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This article covers how to install and use Logwatch on Ubuntu Linux System. Logwatch is a system log analyzer and send that report to email. It generates a summarized log report which contains sshd - authentication failures, sudo - sessions opened, vsftp failures, postfix, failed logins, disk space and more. To find more information, visit the Logwatch man page.

Logwatch can be installed simply from the Ubuntu repository. First update the system.

$ sudo apt-get update

To install Logwatch, execute the command:

$ apt-get install logwatch



This article covers Zoom client's installation procedure. You can now proceed and start or join meetings with the security and reliability that Zoom provides.



This article covers how to install the KONG API Gateway on Ubuntu 20.04. These Gateways provides services like Authentication, rate-limiting, analysis, logging etc., to your API endpoints.

To Start kong API, run the following commands:

$ kong migrations up #runs the database migrations
$ sudo kong start
$ curl -i http://localhost:8001

To Stop and see status of kong API, run the following commands:

$ sudo kong stop #stop kong
$ sudo kong health #kong status



This article covers to install and configuren Graylog in ubuntu. With this, you can work with the log using the Graylog server. Graylog is an open-source tool that offers an integrated platform for collecting, indexing, and analyzing log data. The system essentially consists of the Graylog web interface, the Graylog servers, the Elasticsearch nodes, and a Mongo database.


How to Access Graylog Web interface ?

Open a browser on your local system or remote that can access the Ubuntu 20.04 server Ip-address. And type the http://your-server-ipaddress:9000

Replace your-server-ip-address with the actual IP address of your Server where Graylog has been installed.



This article covers easy steps to install the NtopNG utility on your Linux Mint 20 system. Once it is installed on your system, you can start using it for network traffic monitoring after configuring it according to the specifications of your machine.

To check whether NtopNG is installed or not, run the command:

$ systemctl status ntopng

To start NtopNG service, execute the command:

$ systemctl start ntopng



This article covers how to start, stop and restart the httpd service on CentOS 8 system with the help of the systemctl command. Using this utility, you can easily control any systemd and server-wide service on your system. 

Linux provides fine-grained control over system services through systemd, using the systemctl command. Services can be turned on, turned off, restarted, reloaded, or even enabled or disabled at boot. If you are running Debian 7, CentOS 7, or Ubuntu 15.04 (or later), your system likely uses systemd.



This article covers how to quickly install the Siege tool on your Linux system and use it to test any specific web server. Siege is an open-source multi-threaded regression test and benchmark utility with a primary focus on load testing and benchmarking. It can stress test a single URL with a user-defined number of simulated users or read many URLs into memory and stress them simultaneously. The program reports the total number of hits recorded, bytes transferred, response time, concurrency, and return status.


To Install Siege Benchmarking Tool on Ubuntu / Debian,

1. Check and update your Ubuntu 20.04 operating system:

$ sudo apt update && sudo apt upgrade -y

2. Install Siege execute the following command:

$ sudo apt install siege -y

3. Confirm the siege version to make sure it's installed and to compare it to the current version from Siege's official website:

$ siege --version



This article covers the Installation process of NodeJS on Rocky Linux. Nodejs is a JavaScript runtime built on Chrome's V8 JavaScript engine and is designed to build scalable network applications.



This article covers how to install the Logwatch utility on your Linux server. With Logwatch, you will be able to keep an eye on your server logs and hence, you can quickly figure out any possible issues.

You can easily customize Logwatch to your preference by modifying the parameters in the /etc/logwatch/conf path. It also provides something extra in the way of pre-written PERL scripts for making log parsing easier.

All the default settings are defined in the /usr/share/logwatch/default.conf/logwatch.conf file. The recommended practice is to leave this file intact and instead create your own configuration file at the /etc/logwatch/conf/ path by copying the original config file and then define your custom settings.


Logwatch comes with a tiered approach and there are 3 main locations where configuration details are defined:

  • /usr/share/logwatch/default.conf/*
  • /etc/logwatch/conf/dist.conf/*
  • /etc/logwatch/conf/*


To install Logwatch on your server.

On Ubuntu:

$ sudo apt-get install logwatch

On Debian:

$ apt-get install logwatch



This article covers how you can install Dropbox on the CentOS system and sync your local files and folders with Dropbox cloud storage. Dropbox is a useful file-sharing and syncing service that lets you sync files between different machines over the Internet for free. It's very useful for backing up your important documents, pictures, MP3 files, video files, and other data.



This article covers how to install Grafana on Ubuntu OS using two methods: using the APT repository and the .deb package. Grafana is multi-platform open-source analytics and interactive visualization web application that integrates with complex data from sources like Prometheus, InfluxDB, Graphite, and ElasticSearch. It provides charts, graphs, and alerts for the web when connected to supported data sources. It is expandable through a plug-in system.


Features of Grafana:

  • Data Visualization: Allows for fast and flexible visualization with many options and settings.
  • Dynamic Dashboards: Provides the ability to create dynamic and reusable panels with templated variables.
  • Metrics Exploration: Explore your data with ad-hoc queries and dynamic drill-down by splitting the view and comparing different time ranges and sources.
  • Data Logs: Provides tremendous opportunities to use data metrics in a log with labels and filters saved, which can be studied, viewed, and broadcasted.
  • Extensive Alert Capabilities: Visually define alert rules for your most important metrics. Grafana will continuously evaluate and send notifications to systems such as Slack, PagerDuty, VictorOps, and OpsGenie.
  • Mixed Data Sources: Mix different data sources on the same graph and for each query.



This article covers the process of migrating to AlmaLinux from CentOS 8. AlmaLinux OS is a new RHEL fork from the team at CloudLinux. It is meant to be a free Linux Operating System, developed in close co-operation with the community, and for the community. As of this article update, the release of AlmaLinux available is not stable fit for production use. AlmaLinux OS is now stable and can be used in Production environments.


To Migrate from CentOS 8 To AlmaLinux 8.4.

1. Download the almalinux-deploy.sh script:

$ curl -O https://raw.githubusercontent.com/AlmaLinux/almalinux-deploy/master/almalinux-deploy.sh

2. Give the script execution bits:

$ chmod +x almalinux-deploy.sh

3. Then run the script with the commands below:

$ sudo bash ./almalinux-deploy.sh



This article covers how to add users into the sudoers group. Also you will learn how to edit rules in the sudoers configuration file through the command. You can customize the sudoers file based on the user requirements. Sudo stands for superuser do. Sudo is a command used in Unix-like systems to allow a regular user to execute a program as another user. In most cases, it is the root user.

The sudo command allows authorized users to perform commands as another user, which is by default the root user. 

This option gives you administrator-level permissions to run programs on your machine. It is an alternative to using the su command.



This article covers how you can easily install Cockpit on your CentOS system and manage other Linux servers. With Cockpit, you can have a quick glance at the performance of all your added servers. Also, you can monitor system resources, start and stop services, shut down the system, install updates, view network activity (send/received). create or remove user accounts, access Terminal, and much more on the remote servers. Cockpit helps to save a lot of time by letting the administrators manage the remote servers that are spread across the network using a lightweight and intuitive interface. 


Benefits of Cockpit in our GNU/Linux servers:

  • It consists of systemd service manager for ease.
  • It has a Journal log viewer to perform troubleshoots and log analysis.
  • Storage setup including LVM was never easier before.
  • Basic Network configuration can be applied with Cockpit
  • We can easily add and remove local users and manage multiple servers.


To Install  and enable Cockpit packages from repository, run the command:

$ sudo yum install cockpit

Type "y" and it will start downloading and installing the required packages.

To enable the Cockpit with the following command:

# sudo systemctl start cockpit

or

$ sudo systemctl enable --now cockpit.socket


To confirm the status of Cockpit, run the command:

# sudo systemctl status cockpit



This article covers how to easily migrate to Rocky Linux 8.4 from CentOS 8. Rocky Linux is a community enterprise operating system designed to be 100% compatible with RedHat Enterprise Linux. Rocky Linux dev team has created a migration script called migrate2rocky to easily convert an existing CentOS 8 system to Rocky Linux 8.


To Upgrade the current CentOS 8 Linux system to latest available version, run the command:

$ sudo dnf --refresh upgrade

After update is completed, Reboot your system:

$ sudo reboot



This article covers how to install LAMP stack on Rocky Linux 8.4. You can now proceed to test or host your website and applications. A LAMP stack is a group of open-source software that is typically installed together to enable a server to host dynamic websites and web apps. This term is actually an acronym which represents the Linux operating system, with the Apache web server. The site data is stored in a MySQL database, and dynamic content is processed by PHP.


How to Install  and configure Apache Web Server ?

1. First, we will start by installing the Apache web server. To complete the installation, use the following command:

$ yum install httpd httpd-tools

2. Once the installation is complete, enable Apache (to start automatically upon system boot), start the web server and verify the status using the commands below:

$ systemctl enable httpd
$ systemctl start httpd
$ systemctl status httpd

3. To make your pages available to public, you will have to edit your firewall rules to allow HTTP and HTTPS requests on your web server by using the following commands:

$ firewall-cmd --permanent --zone=public --add-service=http 
$ firewall-cmd --permanent --zone=public --add-service=https 
$ firewall-cmd --reload
4. Verify that the web server is running and accessible by accessing your server’s IP address:
$ echo "Hello there, Apache webserver is now running" > /var/www/html/index.html

5. And restart tht Web Server to reflect the changes made:

$ systemctl restart httpd

From your browser,

http://IP_address


How to Install PHP on CentOS ?

1. To install PHP on your RHEL 8 use the command below:

$ yum install -y php-mysqlnd php-dom php-simplexml php-xml php-xmlreader php-curl php-exif php-ftp php-gd php-iconv  php-json php-mbstring php-posix php-sockets php-tokenizer

2. Now restart your web server so that Apache knows that it will be serving PHP requests as well:

$ systemctl restart httpd



This article covers how you can easily install the GIMP image editor on your CentOS system. GIMP is the acronym for GNU Image Manipulation Program. It is free and open source raster graphics editor used for image retouching and editing, free form drawing, converting between image formats and many more tasks. It is released under GPL3 license and is available for Linux, Microsoft Windows and MacOS.


How to Install and use Gimp graphical editor on Linux?

You can install gimp package by using the dnf command:

# dnf install gimp

You can Start Gimp graphical editor from your menu or by executing the following command:

$ gimp



This article covers how to install and configure OpenLiteSpeed webserver. OpenLiteSpeed is an easy-to-use, open-source web server. It offers unbeatable features and performance to your sites along with top-notch security. Also, it understands all the apache rewrite rules and has intelligent cache acceleration features that let you implement the fastest caching on your server. Apart from all these, you get to install a customized PHP processor that is optimized for the OpenLiteSpeed server.


OpenLiteSpeed server's Frontend (default page) is located at:

http://<your-server-public-IP>:8088

It's backend (admin console) is located at:

https://<your-server-public-IP>:7080



This article covers the installation methods( Yum package manager or via direct download method), you can easily install Apache Maven on CentOS. Apache Maven is basically a software project management and comprehension tool. 


How to check Apache Maven on Linux?

Use the following command to check the version of installed Maven on your system:

$ mvn -version



This article covers method to permanently disable SELinux on CentOS 7. SELinux, also known as Security-Enhanced Linux, is a security feature embedded in the Linux kernel. SELinux leverages Mandatory Access controls (MAC) to confine users to certain rules and policies and prevents them from performing unauthorized tasks on the Linux system as specified by the IT administrator

To Check SELinux status, simply run the command:

# sestatus



This article covers PostgreSQL 13 installation on Rocky Linux 8.4. Basically, PostgreSQL is the world's most advanced open source database system. And with the release of PostgreSQL 13 there are significant improvements to the indexing and lookup system that benefit large databases, and faster response times for queries that use aggregates or partitions.


How to Enable and Start PostgreSQL Service ?

To enable and start the PostgreSQL database service so that it can start automatically with system boot:

$ sudo systemctl start postgresql-13
$ sudo systemctl enable postgresql-13

To confirm everything is working fine, check the status of PostgreSQL service:

$ sudo systemctl status postgresql-13



This article covers how to install Gitea on Ubuntu 20.04 LTS. Gitea is a self-facilitated open-source git worker written in Go. It is a fork of Gogs . Gitea incorporates a store record supervisor, venture issue following, clients administrations, notices, implicit wiki, and considerably more. 

To Install Git on Linux, run the commands: 

$ sudo apt update
$ sudo apt install git

To Confirm Git Installation, execute the command: 

$ git --version



This article covers the installation of a puppet server on both master and client nodes and how to connect them. Ensure that you sign the puppet agent node certificate for both the master and client-side.

Puppet is a free and open-source automated administrative engine for Linux, Unix, and Windows operating systems. It is used for deploying, configuring, and managing servers and performs administrative tasks such as adding users, installing packages, and many more. It helps system admins to free up time and mental space by automating tasks on thousands of physical and virtual machines. It uses a client-server model. Where Puppet master controls configuration information for Puppet agents while Puppet agents talk to and pull down configuration profiles from the Puppet master.



This article covers the installation steps of Flatpak on the CentOS 8 system. With Flatpak, users can easily install new packages or applications from the flathub repository in an isolated space.

Flatpak is a package management system that aims to enable  users and developers to install and manage software packages on Linux systems regardless of the Linux distribution, runtime, dependencies and the type of package management. A flatpak application runs in a sandboxed environment. This is an isolated environment that is bundled with all the dependencies, libraries and everything that is needed for the app to run smoothly. 


How to Enable Flatpak in Red Hat / CentOS / Fedora ?

For RedHat / CentOS 8 and Fedora 22 and later versions, invoke the command below to enable flatpak:

$ sudo dnf install flatpak

For earlier versions of Red Hat and CentOS use the YUM package manager:

$ sudo yum install flatpak



This article covers how to Install Monit monitoring server on the Ubuntu 20.04 system. Monit is an open-source utility used to supervise the processes and restart the services which are configured for it and have failed. Monit supervises the processes and restarts them on failure detection. Apart from the processes, Monit can also be used to monitor CPU, RAM, Disk, File Size and trigger alerts on out-of-bound values. It also shows how to trigger alert emails using custom templates. 

Now you can easily monitor your system using this lightweight tool.


To Install Monit on Ubuntu, run the following commands:

$ sudo apt update
$ sudo apt install monit



This article covers how to add and remove users in the sudo group to manage the sudo privileges of the users. sudo is a command-line program that allows trusted users to execute commands as root or another user.



This article covers how to Install JFrog Artifactory on Ubuntu. JFrog Artifactory is the world’s most advanced repository manager designed to integrate with the majority of continuous integration and delivery tools. With JFrog Artifactory, delivering an end to end automated solution with artifacts tracking from development to production becomes a reality.

Jfrog provides you with an interactive, responsive user interface. It has more features than other artifactory management tools. For more information please visit the official site of JFrog. https://jfrog.com/open-source



This article covers how to enable SSH on a CentOS machine and connect to it using a client machine. If you want to make your remote access secure, Read our post on the Best Ways to Secure Your SSH Server.

SSH provides the ability to transfer files between remote systems. When a user logs into a remote system using SSH, they receive a command prompt allowing them to enter commands on the remote system as if they were sitting at the remote system and had opened a terminal session.


How to Install OpenSSH Server Software Package ?

Enter the following command from your terminal to start the installation process:

$ sudo yum –y install openssh-server openssh-clients

This command installs both the OpenSSH client applications, as well as the OpenSSH server daemon, sshd.



This article covers different methods to install the emacs editor on CentOS 8 system. Emacs is one of the oldest and most versatile text editors available for Linux and UNIX-based systems. It's been around for a long time (more than twenty years for GNU emacs) and is well known for its powerful and rich editing features. Emacs is also more than just a text editor; it can be customized and extended with different "modes", enabling it to be used like an Integrated Development Environment (IDE) for programming languages like Java, C or Python.


To Install Emacs via EPEL repository, Run the following command:

$ sudo dnf update
$ sudo dnf install epel-release
$ sudo dnf install emacs



This article covers the installation and basic configuration of Elasticsearch on the CentOS system. For how to use Elasticsearch, visit the Quick start guide available on its website. Elasticsearch is an open source search and analytics engine that allows you to store, search, and analyze big volumes of data in real time. Elasticsearch powers millions of Applications that rely on intensive search operations such as e-commerce platforms and big data applications. 

Elasticsearch supports RESTful operations. This means that you can use HTTP methods (GET, POST, PUT, DELETE, etc.) in combination with an HTTP URI (/collection/entry) to manipulate your data. The intuitive RESTful approach is both developer and user friendly, which is one of the reasons for Elasticsearch's popularity.



This article covers How to Install kdevelop in Ubuntu Linux System. KDevelop is a robust IDE that includes useful extensions, and also several high-quality features. KDevelop is a great option of IDE for Linux distributions due because of its stability and security.

To Install kdevelop software package in Ubuntu, run the following command:

$ sudo apt-get update
$ sudo apt-get install kdevelop



This article covers how to add a user as well as how to remove it in case you no longer need it. We also described how to add and remove a user to and from a group. If you are using Ubuntu distribution, visit how to add or remove users in Ubuntu

You may need to create separate account for every user want to connect this system. To add new users in system there are two commands available in your system, useradd and adduser. adduser command is the enhanced version of useradd command. adduser command uses useradd command in backend. 



This article covers how to Run Jenkins Server in Docker Container with Systemd. Jenkins is an opensource automation server that is designed to help software developers build, test and deploy applications and thereby streamline the continuous integration and delivery process. 

To create a system group for Jenkins, run the command:

$ sudo groupadd --system jenkins

Then create Jenkins system user:

$ sudo useradd -s /sbin/nologin --system -g jenkins jenkins

And finally add Jenkins user to docker group as shown:

$ sudo usermod -aG docker jenkins

To confirm that Jenkins user is added to the docker group, run the id command as shown:

$ id jenkins



This article covers how to change the ssh port on Ubuntu Linux server. You can easily change the SSH Port for Your Linux server. For better security, consider using SSH passwordless authentication with SSH public/private key pair.

The ssh port defined in sshd_config file. This file located in /etc/ssh/sshd_config location.

To open the new port run the following commands on Fedora/CentOS/RHEL/Oracle Linux using FirewallD:

$ sudo firewall-cmd --permanent --zone=public --add-port=2222/tcp
$ sudo firewall-cmd --reload


How to Restart the sshd service ?

Type the following command on a CentOS/RHEL/Fedora Linux:

$ sudo service sshd restart

OR if you are using CentOS/RHEL/Fedora Linux with systemd:

$ sudo systemctl restart sshd

OR if you are using Ubuntu/Debian/Mint Linux:

$ sudo service ssh restart

OR if you are using Ubuntu/Debian/Mint Linux with systemd:

$ sudo systemctl restart ssh

Or if you are using FreeBSD Unix, enter:

$ sudo service sshd restart



This article covers the three different methodologies of installing Thunderbird in Ubuntu. Thunderbird is available for various distributions like macOS, Linux, Microsoft Windows etc. thereby making it a cross platform application.

To Install Thunderbird through apt:

1. First update Ubuntu repository,

$ sudo apt update

2. Now, to install Thunderbird issue the following in terminal,

$ sudo apt install thunderbird

3. Lastly, Thunderbird can accessed either through System's main Menu or from terminal (Run "thunderbird" in terminal to run the application).



This article covers how to install harbor on Ubuntu. The process is the same for all the other distribution of Linux. Harbor is a component of vSphere with Kubernetes. Harbor provides an enterprise-class registry service. 

Harbor is deployed in a dedicated system namespace on the Supervisor Cluster and is composed of several vSphere Pods. 

Image registries provide a centralized repository for an organization to store container images. 

Public image registries can be used to store container images. However, for security reasons, it is better to use an on-premises image registry. 

You use an on-premises image registry for the following purposes: 

Store container images securely. 

Control access to container images. 

vSphere with Kubernetes is integrated with Harbor and is also compatible with other container image registries. 


Harbor key features includes:

  • Security and vulnerability analysis.
  • Content signing and validation.
  • Extensible API and web UI.
  • Image replication.
  • Role-based access control.
  • Multitenant.


After Harbor installation has succeeded, access Harbor web console on https://registry_domain.

Then Login with:

  • Username: admin
  • Password: Set-in-harbor.yml



This article covers the different methods to install Emacs on Debian OS. Emacs is a widely used open-source text editor for Linux. It exists for many years now and can be used for basic word processing, code editing, and scripting, etc.


How to Install Emacs editor on Debian ?

1. To start the installation process, login with root and update the package repository with the following command.

$ apt-get update

2. Next, run the following command on the terminal and wait for the operation to complete. This can take several minutes. When you are asked for confirmation, press Y from your keyboard.

$ apt-get install emacs



This article covers how to install notepadqq on Ubuntu 20.04 Linux system. Notepad is a similar copy of the most popular editor notepad++. Basically, Notepadqq is a text editor that is designed by developers for the developers. It supports more than 100 languages and useful to note down daily tasks.


How to Install Notepadqq on Debian / Ubuntu?

1. Add Repository

$ sudo add-apt-repository ppa:notepadqq-team/notepadqq  

2. Update Repository

$ sudo apt-get update  

3. Install Notepadqq

$ sudo apt-get install notepadqq  

4. After installation, we can access it either via terminal by typing notepadqq or by searching from the application manager. Run Notepadqq:

$ notepadqq 



This article covers how to install elasticsearch in the stable version of Ubuntu 20.04. Now you can use the hosted elasticsearch server for doing searches.

If your application generates a huge amount of data and the search procedures are slow, then using elasticsearch will be best.



This article covers how to Install putty on CentOS 8. With putty, you can easily connect your Linux system to a remote system. Putty is a free and open source ssh & telnet client. Putty is available for Windows, Linux, Unix and macOS. Using putty, we can access the remote servers and switches over ssh protocol. It can also be used to take serial console of remote systems.


How to perform Putty Installation on CentOS / RHEL / Fedora ?

Putty package is available in the default CentOS and RHEL repositories. So, to install putty run:

$ sudo yum install putty -y

Or

$ sudo dnfs install putty -y



This article covers methods to install Nmap on your CentOS machine. Nmap is a handy utility for network scanning and security auditing. Nmap contains variety of options for scanning remote hosts. Have a look at the 15 Mostly Used Nmap Commands for Scanning Remote Hosts.



How to Install Nmap on Debian / Ubuntu ?

1. Install Nmap on Ubuntu by entering the following command:

$ sudo apt-get install nmap

2. The system prompts you to confirm the installation by typing y.

3. After the installation is finished, verify the installed version of Nmap by entering:

$ nmap –version



This article covers how to install Go on CentOS 8. Go language was designed to resolve the common criticisms of other languages while maintaining their positive characteristics and most widely used for writing servers these days.


Run the below command to see the version of the Go language:

$ go version



This article covers how to install GitLab on your local devices or server. Also, you will learn how to integrate the GitLab CE into our local Ubuntu system. GitLab CE, or Community Edition, is an open-source application primarily used to host Git repositories, with additional development-related features like issue tracking. It is designed to be hosted using your own infrastructure, and provides flexibility in deploying as an internal repository store for your development team, a public way to interface with users, or a means for contributors to host their own projects.



This article covers the installation of Apache NetBeans on the CentOS system. Here, you will learn the entire procedure for the installation of NetBeans that includes downloading, installation, and launching of NetBeans. At the end, you also learned to uninstall Apache NetBeans if you ever have to do that.

Apache NetBeans is a very powerful Integrated Development Environment (IDE) tool that enables you as a Developer create Desktop, Web and Mobile Applications from its modular framework. It supports Java, PHP, HTML, JavaScript, C, C++, Ajax, JSP, Ruby on Rails and other programming languages using extensions.



This article covers how to install the Wireshark network analyzer tool on CentOS 8 system. Once Wireshark installed on your system, you can capture incoming and outgoing data packets over the network. Wireshark is free & Open source network packet analyzer that is used for network analysis, troubleshooting, etc. Wireshark is a cross-platform software that is available for various Linux/UNIX distributions, Mac-OS, Solaris, BSD & Windows, etc. It uses GTK to implement user interface & captures packets using PCAP. For additional help or useful information, we recommend you to check the official Wireshark website.


To Install package called Whireshark using the dnf command. For a GUI Wireshark application execute:

# dnf install wireshark

To install Wireshark command line tool only execute:

# dnf install wireshark-cli



Features of Wireshark includes:

  • Live packet capture & offline analysis.
  • A number of display filters.
  • Support for hundreds of protocol.
  • Rich VOIP analysis.
  • Read/write feature various file formats.
  • Live data can be read from ethernet port, Bluetooth, USB, Token rings tec.



This article covers how you can monitor the temperature of your CPU cores, hard drive and other components attached to the motherboard.

When your PC is overheating, consider disassembling your PC and blowing it with a blower to get rid of all the dust which might be blocking the ventilation vents.

Also, ensure your laptop is placed on a hard surface and not on a cushy surface such as on a bed where the vents can easily get blocked.

Lastly, enable power saving mode and close any unnecessary applications.



This article covers how to install vim, followed by some basics on using vim and then uninstalling it. Vim (Vi IMproved) is a text editor that is upwards compatible to Vi. It can be used to edit all kinds of plain text. It is especially useful for editing config files and programs written in shell, python, perl, c/c++ and more. 

Among the various text editors in the world of Linux, Vim (or Vi IMproved) stands out for its versatility and for the functions it offers. In fact, Vim is able to speed up code writing, providing some shortcuts to perform all the operations of modification, deletion or replacement of the text. 

Vim Text Editor also allows you to install different plugins through which transforming this simple text editor into a real IDE for programming in different languages.


How to Install vim using apt on Linux ?

1. Open terminal application. You can also press CTRL+ALT+T keyboard shortcut.

2. Update package database by typing the sudo apt update command.

3. Search for vim packages run: sudo apt search vim.

4. Install vim on Ubuntu Linux, type: sudo apt install vim.

5. Verify vim installation by typing the vim --version command.



This article covers how to install the Nginx server on a CentOS machine and add a firewall rule to allow traffic coming towards the Nginx server. Also, we've discussed how to remove Nginx from CentOS.

The Nginx is a free, open source, lightweight and high-performance web server designed for high-traffic use cases. It is also acting as a popular Web server behind the Apache Web server and Microsoft's IIS. Nginx is more resource-friendly than Apache. It can be served in front of other web servers as a reverse proxy.


How to Install Nginx Web Server ?

1. Install the nginx package with:

$ sudo dnf install nginx

2. After the installation is finished, run the following commands to enable and start the server:

$ sudo systemctl enable nginx
$ sudo systemctl start nginx

This will make Nginx start at system boot.



This article covers how to install and manage multiple Java versions on CentOS 7 system. At the end you also learned how to set default Java version. Java is used for developing anything from lightweight mobile to desktop applications.


How to Install Java 8 on CentOS ?

1. Update the system before installing any new programs:

$ yum -y update

2. Install Java 8:

$ yum install java-1.8.0-openjdk

3. Verify Java is Installed

$ java -version



This article covers how to get CentOS version using different methods. There are several ways on how to check what version of CentOS is running on your system. The simplest way to check for the CentOS version number is to execute the cat /etc/centos-release command. Identifying the accurate CentOS version may be required to help you or your support team to troubleshoot your CentOS system.


Different commands to check CentOS version:

  • $ rpm -q centos-release - CentOS version valid for CentOS 6 and higher. Causes to reveal major, minor and asynchronous CentOS version.
  • $ lsb_release -d - Requires redhat-lsb package to be installed before execution.
  • $ rpm -E %{rhel} - RPM macro to reveal a major CentOS version.
  • $ rpm --eval %{centos_ver} - RPM macro to display a major version of CentOS.
  • $ cat /etc/centos-release - Linux cat command to output content of the /etc/centos-release .to query CentOS version. Works with CentOS 6 and higher.



This article covers how to install the Curl command-line tool on CentOS 8 system. Through the curl command, users can download and upload files over the network. curl is a powerful command-line tool for transferring data from or to a remote server. With curl you can download or upload data using various network protocols, such as HTTP, HTTPS, SCP , SFTP , and FTP .


How to Install curl on CentOS ?

Curl package is available in the standard CentOS 8 repositories. 

To install it run the following command:

$ sudo dnf install curl

Once the installation is complete, verify it by typing curl in your terminal:

$ curl



This article covers how to install Arduino IDE on CentOS machine either via the direct download method or the snap method. Also, you will learn how to uninstall Arduino. Arduino IDE stands for the "Arduino Integrated Development Environment". Arduino is used to create electronic devices that communicate with their environment using actuators and sensors. Arduino IDE contains an editor that is used for writing and uploading programs to the Arduino board. Before starting to create projects through Arduino, the user needs to set up an IDE for the programmable board.


How to Launch Arduino IDE on CentOS Linux System ?

Now, you will launch the Arduino IDE from the desktop. Click on 'Activities' and select show application form where you will launch Ardunio IDE to double click on the application icon.

You can also launch using the search bar, click on the 'Activities' where you can see a search bar. You will type 'Arduino' in the search bar.



This article covers how to Install phpMyAdmin with Nginx on Ubuntu 18.04 system. When developing a website or web application, many users need the functionality of a database system like MySQL. However, interacting with the system solely from the MySQL command-line client requires familiarity with Structured Query Language — more commonly referred to as SQL — which can present a major hurdle for some users. phpMyAdmin was created to allow users to interact with MySQL through an intuitive web interface, running alongside a PHP development environment. 


How to Secure phpMyAdmin with Let's Encrypt SSL ?

Before starting, you will need to install the Certbot client to download and install Let's Encrypt SSL.

1. First, add the Certbot repository with the following command:

$ add-apt-repository ppa:ahasenack/certbot-tlssni01-1875471

2. Next, update the repository and install the Certbot client using the following command:

$ apt-get update -y
$ apt-get install certbot python3-certbot-nginx -y

3. Once the Certbot has been installed, run the following command to download and install the Let's Encrypt SSL for your domain:

$ certbot --nginx -d phpmyadmin.domain.com



This article covers how to install LAMP stack on CentOS 7. LAMP is a stack of applications that work together on a web server to host a website. With that being said, each individual program serves a different purpose.

In LAMP: 

  • Linux serves as the server's operating system that handles all the commands on the machine.
  • Apache is a web server software that manages HTTP requests to deliver your website's content.
  • MySQL is a relational database management system (RDBMS) whose function is to maintain user's data on a server.
  • PHP is a scripting language for server-side communication.


To install Apache easily using CentOS's package manager, yum:

1. Run the command.

$ sudo yum install httpd

2. Once it installs, you can start Apache on your server.

$ sudo systemctl start httpd.service

3. You can do a spot check right away to verify that everything went as planned by visiting your server's public IP address in your web browser.

http://your_server_IP_address/


Important PHP Modules:

  • php-bcmath.x86_64 : A module for PHP applications for using the bcmath library.
  • php-cli.x86_64 : Command-line interface for PHP.
  • php-common.x86_64 : Common files for PHP.
  • php-dba.x86_64 : A database abstraction layer module for PHP applications.
  • php-devel.x86_64 : Files needed for building PHP extensions.
  • php-embedded.x86_64 : PHP library for embedding in applications.
  • php-enchant.x86_64 : Enchant spelling extension for PHP applications.
  • php-fpm.x86_64 : PHP FastCGI Process Manager.
  • php-gd.x86_64 : A module for PHP applications for using the gd graphics library.



This article covers how to install Skype on your CentOS 7 desktop system. Running Skype on CentOS/Fedora allows you to make Skype calls, group video calls, instant messaging, phone number calls, and screen sharing.


How to Install Skype on CentOS | Fedora ?

The easiest and quickest way to install Skype on Fedora 34/33/32/31/30 is by using the RPM package. 


1. Download the package using wget command:

$ wget https://repo.skype.com/latest/skypeforlinux-64.rpm

2. Install Skype by running the commands:

### On CentOS and Red Hat systems ###
$ sudo yum localinstall skypeforlinux-64.rpm
### On Fedora 22+ systems ###
$ sudo dnf localinstall skypeforlinux-64.rpm

3. Use the following command to launch Skype from the command line and accept terms and conditions for the first time.

$ skypeforlinux



This article covers how to create a new SSH key pair and set up an SSH key-based authentication. You can set up same key to multiple remote hosts on CentOS system. Also, you will learn how to disable SSH password authentication.

SSH, or secure shell, is an encrypted protocol used to administer and communicate with servers. When working with a CentOS server, chances are, you will spend most of your time in a terminal session connected to your server through SSH.

SSH keys are typically configured in an authorized_keys file in . ssh subdirectory in the user's home directory. Typically a system administrator would first create a key using ssh-keygen and then install it as an authorized key on a server using the ssh-copy-id tool.

The public key should be stored in the ~/. ssh/authorized_keys file on the server.


To Create the RSA Key Pair:

1. Execute the command below to create a key pair on the client machine (usually your computer):

$ ssh-keygen

2. Press ENTER to save the key pair into the .ssh/ subdirectory in your home directory, or specify an alternate path.


Best Practices to improve SSH Key Security:

  • Discover all SSH Keys and Bring Under Active Management.
  • Ensure SSH Keys Are Associated With a Single Individual.
  • Enforce Minimal Levels of User Rights Through PoLP.
  • Stay Attentive to SSH Key Rotation.
  • Eliminate Hardcoded SSH Keys.
  • Audit All Privileged Session Activity.



This article covers how to stop and disable FirewallD on your CentOS 7 system. Firewalld is a complete firewall solution that has been made available by default on all CentOS 7 servers. It is highly recommended that you have another firewall protecting your network or server before, or immediately after, disabling firewalld.


How to manage Firewalld ?

1. To disable firewalld, run the following command as root:

$ systemctl disable firewalld

2. To Stop Firewalld, execute the following command as root:

$ systemctl stop firewalld

3. To check the status of firewalld, run the following command as root:

$ systemctl status firewalld



This article covers how to install Apache Cassandra on Ubuntu 20.04 LTS. Apache Cassandra is an open-source non-relational database that delivers high performance, linear scalability, and continuous availability. All these features make Cassandra an ideal platform for mission-critical data.

To learn more about Apache Cassandra, visit its official documentation site.


How to install Java on Ubuntu ?

1. To check whether Java is installed, run the command:

$ java -version

2. To install OpenJDK, execute the following apt command:

$ sudo apt install openjdk-8-jdk

3. Once again, confirm that Java is installed by running the command:

$ java -version


How to Install Apache Cassandra in Ubuntu ?

1. First, install the apt-transport-https package to allow access of repositories via the https protocol:

$ sudo apt install apt-transport-https

2. Next, Import the GPG key using following wget command as shown:

$ wget -q -O - https://www.apache.org/dist/cassandra/KEYS | sudo apt-key add -

3. Then add Apache Cassandra's repository to the system’s sources list file as shown:

$ sudo sh -c 'echo "deb http://www.apache.org/dist/cassandra/debian 311x main" > /etc/apt/sources.list.d/cassandra.list'

4. Before installing Apache Cassandra, you need to update the package list first:

$ sudo apt update

5. Then install the NoSQL database using the command:

$ sudo apt install cassandra

6. Usually, Apache Cassandra starts automatically. To confirm its status, run the following command:

$ sudo systemctl status cassandra

7. Additionally, you can verify the stats of your node by running the command:

$ sudo nodetool status



This article covers how to change timezone in CentOS 7. A time zone is basically a region of the globe that observes a uniform standard time for constitutional, business and cultural purposes.

To get detailed information your CentOS server's date, time, and timezone you use the timedatectl command:

$ timedatectl

To Delete the current /etc/localtime file or symlink:

$ sudo rm -rf /etc/localtime



This article covers how to change the hostname on CentOS 7 using different methods. By default, your server is started with the server's given name as the hostname. Some software such as cPanel requires a valid fully qualified domain name (FQDN) for the hostname to be used during their licensing verification system.


To Change a server's hostname:

1. Using a text editor, open the server's /etc/sysconfig/network file. The following example shows how to open this file in the GNU nano text editor:

# sudo nano /etc/sysconfig/network

2. Modify the HOSTNAME= value to match your FQDN hostname, as shown in the following example:

HOSTNAME=myserver.domain.com

3. Open the file at /etc/hosts. To update the information for internal networking, change the host that is associated with the main IP address for your server, as shown in the following example:

127.0.0.1      localhost localhost.localdomain
123.45.67.89   hostname.domain.com   hostname

4. Run the hostname command. This command enables you to change the hostname on the server that the command line remembers, but it does not actively update all of the programs that are running under the old hostname. The following code provides an example:

# hostnamectl set-hostname hostname.domain.com
# hostname
hostname.domain.com
#

5. Use the following command to restart networking on your server to ensure that changes persist on restart:

# /etc/init.d/network restart



This article covers how to change SSH port on your Linux system. SSH (Secure shell) is a cryptographic network protocol used to connect to a remote server securely and it transfer the data in encrypted form between the host and the client.

The default TCP port for SSH is 22, and by changing this default port to the other, it can prevent automated bots and malicious users from being brutally forced into the server.

Before changing the default SSH port number, can check the current port with the below command:

# netstat -ntlp | grep ssh


To change the SSH port:

1. Open the main SSH daemon configuration file /etc/ssh/sshd_config:

# vi /etc/ssh/sshd_config

2. Now search line begins with Port 22 and add hashtag (#) in front of that line. 

3. Then add a new Port line below with the custom port.

Note: Replace the sample port number with the custom port number that needs to be set.

4. Save and exit.


How to Restart the SSH daemon for the changes to take effect ?

Run the below commands to restart the SSH daemon and verify that the port changed:

# systemctl restart sshd
# netstat -ntlp | grep ssh



This article covers how to install Git on your Debian server and how to Setting up Git. With versioning tools such as Git, you can track changes, revert to previous stages, and branch to create alternate versions of files and directories.


How to Install Git with Default Packages on Debian?

1. First, use the apt package management tools to update your local package index. 

After updating the system, you can download and install Git:

$ sudo apt update
$ sudo apt install git

2. You can confirm that you have installed Git correctly by running the following command:

git --version



This article covers how to disable FirewallD and install and iptables on CentOS 7 server. The iptables service stores configuration in /etc/sysconfig/iptables and /etc/sysconfig/ip6tables , while firewalld stores it in various XML files in /usr/lib/firewalld/ and /etc/firewalld/ . 

Note that the /etc/sysconfig/iptables file does not exist as firewalld is installed by default on Red Hat Enterprise Linux.

FirewallD is a complete firewall solution that can be controlled with a command-line utility called firewall-cmd. If you are more comfortable with the Iptables command line syntax, then you can disable FirewallD and go back to the classic iptables setup.


To Install and Use Iptables Linux Firewall:

1. Connect to your server via SSH.

2. Execute the following command one by one: 

$ sudo apt-get update 
$ sudo apt-get install iptables

3. Check the status of your current iptables configuration by running:

$ sudo iptables -L -v


Location of iptables rules on CentOS ?

CentOS 7 uses FirewallD by default. If you would like to manage iptables/ip6tables rules directly without using FirewallD, you may use the old good iptables-services service which will load the iptables/ip6tables rules saved in /etc/sysconfig/iptables and /etc/sysconfig/ip6tables when it is started during boot time.



This article covers how to configure and manage the FirewallD service on your CentOS system. A Linux firewall used to protect your workstation or server from unwanted traffic. You can set up rules to either block traffic or allow through. You can add or delete or update firewall rules without restarting the firewall daemon or service. The firewall-cmd act as a frontend for the nftables. In CentOS 8 nftables replaces iptables as the default Linux network packet filtering framework. 


To Start and enable firewalld, run the commands:

$ sudo systemctl start firewalld
$ sudo systemctl enable firewalld

To Stop and disable firewalld, run the commands:

$ sudo systemctl stop firewalld
$ sudo systemctl disable firewalld

To Check the firewalld status, run the command:

$ sudo firewall-cmd --state

To Command to reload a firewalld configuration when you make change to rules, run the command:

$ sudo firewall-cmd --reload

To Get the status of the firewalld service, run the command:

$ sudo systemctl status firewalld



This article covers how to install and Secure MariaDB on a CentOS 7 server. MariaDB is a fork of MySQL managed by the original MySQL developers. It's designed as a replacement for MySQL, uses some commands that reference mysql, and is the default package on CentOS 7.


To Install MariaDB 5.5 on CentOS 7:

1. Install the MariaDB package using the yum package manager: 

$ sudo yum install mariadb-server

2. Once the installation is complete, start the MariaDB service and enable it to start on boot using the following commands: 

$ sudo systemctl start mariadb 
$ sudo systemctl enable mariadb


To install MariaDB on CentOS 8:

1. Open the terminal application. Another option is to log in using the ssh command:

 ssh user@centos-8-server-ip

2. Install the MariaDB on CentOS 8 by running the command:

$ sudo yum install mariadb-server

3. Secure the MariaDB server in CentOS 8 by running the command:

$ sudo mysql_secure_installation

4. Finally test MariaDB installation by running the command:

$ mysql -u root -p


MariaDB vs MySQL:

Even though MariaDB is a fork of MySQL, these two database management systems are still quite different: 

MariaDB is fully GPL licensed while MySQL takes a dual-license approach.

MariaDB supports a lot of different storage engines. 

In many scenarios, MariaDB offers improved performance.



This article covers how to install PHP 7.3 on Ubuntu 18.04 server. Also, you will learn how to configure PHP with Apache and Nginx web servers. 


How to Install PHP 7.4 on Ubuntu ?

Use the following set of commands to enable PPA for PHP 7.4 in your Ubuntu system and install it. You can use this version for production use also.

$ sudo apt-get install software-properties-common
$ sudo add-apt-repository ppa:ondrej/php
$ sudo apt-get update
$ sudo apt-get install -y php7.4

Now use the following command to check installed php version on your system.

$ php -v 


How to Install PHP 7 Modules ?

You can install the required PHP modules on your system as below command:

$ sudo apt-get install php7.2-mysql php7.2-curl php7.2-json php7.2-cgi php7.2-xsl



This article covers how to install certbot client, obtain Let's Encrypt SSL certificate and configured to Nginx to use the certificates. Also, you will learn how to set up a cronjob for automatic certificate renewal.

Let's Encrypt is a Certificate Authority (CA) that provides an easy way to obtain and install free TLS/SSL certificates, thereby enabling encrypted HTTPS on web servers. 


To Install Certbot on Ubuntu:

1. First, add the repository.

$ sudo add-apt-repository ppa:certbot/certbot

You'll need to press ENTER to accept.

2. Install Certbot's Nginx package with apt:

$ sudo apt install python-certbot-nginx



This article covers how to install LEMP stack on CentOS 7. LEMP stands for the Linux operating system, with the ENginx web server (which replaces the Apache component of a LAMP stack). The site data is stored in a MySQL-based database, and dynamic content is processed by PHP.

A LEMP software stack is basically a group of open source software that is typically installed together to enable a server to host dynamic websites and web apps.


To install Nginx on CentOS:

1. Add the CentOS 7 EPEL repository, run the following command:

$ sudo yum install epel-release

2. Now that the EPEL repository is installed on your server, install Nginx using the following yum command:

$ sudo yum install nginx

3. Once the installation is finished, start the Nginx service with:

$ sudo systemctl start nginx



This article covers how to install phpMyAdmin with Nginx on CentOS 7 system. phpMyAdmin helps to handle the database administration of MySQL, MariaDB and Drizzle servers over the web. It basically provides the intuitive web interface and supports most of the MySQL features to create and drop databases, create/drop/alter tables, delete/edit/add columns, execute any SQL statement and to manage indexes on columns.


To install phpMyAdmin, run the following commands:

# yum install epel-release
# yum install phpmyadmin


To restart nginx, mariadb and php-fpm services, run the following commands:

# systemctl restart mariadb.service
# systemctl restart nginx.service
# systemctl restart php-fpm.service



This article covers how to Install phpMyAdmin with Apache on CentOS 7 system. phpMyAdmin is a database utility used for managing MySQL databases through a graphical web-based interface. It can be configured to manage a local database (on the same system), or a remote database (over a network).


To Install EPEL Repository:

1. Get access to the EPEL repository – the Extra Packages for Enterprise Linux, by running the command.

$ sudo yum install -y epel-release

2. Once that operation finishes, it's a good idea to refresh and update the EPEL repository.

$ sudo yum –y update


To Install Apache Web Server:

1. Install Apache on CentOS use the command.

$ yum install httpd -y

2. Verify the status of Apache by running with the command.

$ systemctl status httpd


To install PHPMyAdmin on CentOS, enter the command:

$ sudo yum -y install phpmyadmin



This article covers how to create an Nginx server blocks to host multiple website on a single Debian machine. Nginx is a very popular high-performance web server that combines the power of reverse proxying, load balancing, caching and so much more. Depending on how it is configured, it can act as a reverse proxy as well as a load balancer for HTTP/HTTPS servers.


To install Nginx on Debian:

1. Update the Debian 10 Package Repository.

$  sudo apt update -y

2. Install Nginx on Debian 10.

$ sudo apt install nginx -y

3. To check the status of Nginx, execute:

$ systemctl status nginx



This article covers how to install Nginx on your Debian 9 server. Now you can deploy your applications and use Nginx as a web or proxy server. Nginx is more resource-friendly than Apache in most cases and can be used as a web server or reverse proxy.


To install Nginx on Debian:

1. Update our local package index so that we have access to the most recent package listings:

$ sudo apt update

2. We can now install nginx:

$ sudo apt install nginx

When prompted to confirm the installation, hit Enter to proceed. After that, apt will install Nginx and any required dependencies to your server.


Profiles available for Nginx:

  • Nginx Full: This profile opens both port 80 (normal, unencrypted web traffic) and port 443 (TLS/SSL encrypted traffic).
  • Nginx HTTP: This profile opens only port 80 (normal, unencrypted web traffic).
  • Nginx HTTPS: This profile opens only port 443 (TLS/SSL encrypted traffic).



This article covers how to use the certbot Let’s Encrypt client to obtain a free SSL certificate and use it with Nginx on CentOS 7. 

Let's Encrypt is a new Certificate Authority (CA) that provides an easy way to obtain and install free TLS/SSL certificates, thereby enabling encrypted HTTPS on web servers. It simplifies the process by providing a software client, Certbot, that attempts to automate most (if not all) of the required steps. 

Currently, the entire process of obtaining and installing a certificate is fully automated on both Apache and Nginx web servers.


To Install the Certbot Let's Encrypt Client:

1. Enable access to the EPEL repository on your server by typing:

$ sudo yum install epel-release

2. Once the repository has been enabled, you can obtain the certbot-nginx package by typing:

$ sudo yum install certbot-nginx


How to Install Nginx on CentOS ?

1. To install Nginx, run the command:

$ sudo yum install nginx

2. Then, start Nginx using systemctl:

$ sudo systemctl start nginx


How to configure firewall on CentOS ?

If you have a firewall enabled, make sure port 80 and 443 are open to incoming traffic.

1. If you have a firewalld firewall running, you can open these ports by typing:

$ sudo firewall-cmd --add-service=http
$ sudo firewall-cmd --add-service=https
$ sudo firewall-cmd --runtime-to-permanent

2. If have an iptables firewall running, the commands you need to run are highly dependent on your current rule set. For a basic rule set, you can add HTTP and HTTPS access by typing:

$ sudo iptables -I INPUT -p tcp -m tcp --dport 80 -j ACCEPT
$ sudo iptables -I INPUT -p tcp -m tcp --dport 443 -j ACCEPT



This article covers how to create an Nginx server block configuration to host multiple website on a single CentOS server.

Server Blocks, often referred to as Nginx virtual host are a feature of the Nginx web server that allows you to host multiple websites on one server.

To Test NGINX configuration file, run the command:

$ sudo nginx --t

If the syntax is OK, the output tells you the test was successful.


To restart your Nginx web server and confirm that it's running as expected:

$ sudo systemctl restart nginx
$ sudo systemctl status Nginx


To Enable HTTPS on Domain Hosted on Nginx:

You may consider encrypting your domain using Lets Encrypt SSL to add a layer of protection and secure traffic to and from the webserver:

$ sudo dnf install certbot python3-certbot-nginx
$ sudo certbot --nginx



This article covers how to Install and configure Nginx on your CentOS 7 server. Now you can deploy your applications and use Nginx as a web or proxy server. 

Nginx is a high performance web server software. It is a much more flexible and lightweight program than Apache HTTP Server.


To Install Nginx Web Server on CentOS 8:

1. Install the nginx package with:

$ sudo dnf install nginx

When prompted, enter y to confirm that you want to install nginx. After that, dnf will install Nginx and any required dependencies to your server.

2. After the installation is finished, run the following commands to enable and start the server:

$ sudo systemctl enable nginx
$ sudo systemctl start nginx

This will make Nginx start at system boot.


To configure Firewall Rules on CentOS for Nginx:

1. Run the following command to permanently enable HTTP connections on port 80:

$ sudo firewall-cmd --permanent --add-service=http

2. To verify that the http firewall service was added correctly, you can run:

$ sudo firewall-cmd --permanent --list-all

3. To apply the changes, you'll need to reload the firewall service:

$ sudo firewall-cmd --reload



This article covers how to install MariaDB on Ubuntu 18.04 server. Also, you will learn how to secure and connect to MariaDB server. MariaDB is an open-source relational database management system, commonly used as an alternative for MySQL as the database portion of the popular LAMP (Linux, Apache, MySQL, PHP/Python/Perl) stack. Basically, It is intended to be a drop-in replacement for MySQL.


How to Install MariaDB ?

1. To install it, update the package index on your server with apt:

$ sudo apt update

2, Then install the package:

$ sudo apt install mariadb-server



This article covers how to secure Apache with Let's Encrypt SSL on CentOS 7 using Certbot client. Also, you will learn how to set up a cronjob for automatic certificate renewal. Basically, A security certificate is critical for securing traffic sent from web browsers to web servers. Let's Encrypt certificate is a free, open and automated certificate authority that you can use to encrypt your site. The certificate expires after every 90 days and auto-renews at absolutely no cost.


To Install Certbot in CentOS 8.

Certbot is a client that automates the installation of the security certificate. It fetches the certificate from Let's encrypt authority and deploys it on your web server without much of a hassle.

1. Before downloading certbot, first, install packages that are necessary for the configuration of an encrypted connection:

$ sudo dnf install mod_ssl openssl

2. Download certbot using the curl command:

$ sudo curl -O https://dl.eff.org/certbot-auto

3. Next, move the certbot file to the /usr/local/bin directory and assign the execute file permissions:

$ sudo mv certbot-auto /usr/local/bin
$ sudo chmod 755 /usr/local/bin/certbot-auto


To Assign the permissions to the Document root of a domain:

$ sudo chown -R apache:apache /var/www/domain.com

For the changes to come into effect, restart the Apache service:

$ sudo systemctl restart httpd



This article covers how to install and secure a MySQL server on a CentOS 7 server. MySQL is one of the most widely used database management systems for websites and server applications.


To start the MySQL server daemon with the following command:

$ sudo systemctl start mysqld

systemctl doesn't display the outcome of all service management commands, so to be sure we succeeded, we'll use the following command:

$ sudo systemctl status mysqld

To configure MySQL, run the following command:

$ sudo mysql_secure_installation

To Current MySQL Version, run the command:

$ mysql -u root -p


Terms used in Managing MySQL User Permissions:

  • SELECT – users can read through the database using the select command.
  • CREATE – they can generate new tables.
  • DROP – allows users to remove tables.
  • DELETE – users can take out rows from tables.
  • INSERT – lets users add in rows into tables.
  • UPDATE – enable them to update the rows.
  • GRANT OPTION – they can grant or remove the privileges of other users.



This article covers method to easily configure Apache virtual hosts. You repeat same procedure for multiple domain.

You can use yum to install Apache through CentOS's default software repositories:

$ sudo yum -y install httpd

Next, enable Apache as a CentOS service so that it will automatically start after a reboot:

$ sudo systemctl enable httpd.service


How to Set Up Local Hosts File ?

If you are on a Mac or Linux computer, edit your local hosts file with administrative privileges by typing:

$ sudo nano /etc/hosts

The details that you need to add are the public IP address of your VPS followed by the domain that you want to use to reach that VPS:

127.0.0.1   localhost
127.0.1.1   guest-desktop
server_ip_address example.com
server_ip_address example2.com

This will direct any requests for example.com and example2.com on our local computer and send them to our server at server_ip_address.



This article covers how to install specific version of PHP 7 on CentOS 7 Linux server. PHP is a programming language often used to automate server tasks. It is part of the LAMP (Linux, Apache, MySQL, PHP) stack, which is a bundle of software used for running internet servers and services. PHP handles dynamic content, database requests, and processing and displaying data.


To Verify PHP Version:

You can Check which version of PHP you are running with the command:

$ php –v


To Install PHP with Apache on CentOS:

1. Start by installing the yum-utils package by entering the following command in a terminal window:

$ sudo yum install yum-utils –y

2. Then, enable the epel-release repository by entering the following:

$ sudo yum install epel-release –y

3. Finally, add the following software repositories that contain the PHP packages:

$ sudo yum install http://rpms.remirepo.net/enterprise/remi-release-7.rpm

4. For PHP 7.3, you can enable PHP 7.3. Install the release with the following commands:

$ sudo yum-config-manager ––enable remi–php73
$ sudo yum install php php-common php-opcache php-mcrypt php-cli php-gd php-curl php-mysql –y



This article covers how to install Apache on your CentOS 7 system. You can now ready to start deploying your applications and use Apache as a web server.

Basically, The Apache HTTP server is the most widely-used web server in the world. It provides many powerful features including dynamically loadable modules, robust media support, and extensive integration with other popular software.


To Install Apache on CentOS:

1. Update the local Apache httpd package index to reflect the latest upstream changes:

$ sudo yum update httpd

2. Once the packages are updated, install the Apache package:

$ sudo yum install httpd

3. Enable firewalld's http service with the following command:

$ sudo firewall-cmd --permanent --add-service=http

4. Configure Apache to serve content over HTTPS, you will also want to open up port 443 by enabling the https service:

$ sudo firewall-cmd --permanent --add-service=https

5. Finally, reload the firewall to put these new rules into effect:

$ sudo firewall-cmd --reload



This article covers how to create a user with sudo privileges. You can now log in to your CentOS server with this user account and use sudo to run administrative commands.

Performing server administration as a non-root user is a best practice.

For security, your first task when deploying a CentOS instance is to create a non-root user with sudo access.


How to Add a New User Account on CentOS Linux System ?

1. To Create a new user account with the adduser command:

# adduser example_user

2. Set a strong password for the new user (new_user) with passwd.

# passwd new_user



This article covers the installation procedure of Go language on a Linux Mint 20 system. Also, we dealt with an easy way to remove Go language from a Linux Mint 20 system.

To Verify Go Language Installation, run the command:

$ go version 


Features of Go Programming

  • Statically type and compiled programming language.
  • Concurrency support and Garbage collection.
  • Strong library and toolset.
  • Multiprocessing and High-performance networking.
  • Known for readability and usability (Like Python).



This article covers how to install WordPress on Ubuntu 20.04 with Nginx HTTP Server and Let's Encrypt wildcard SSL Certificates. WordPress is a free, open-source, and most popular content management system that allows you to create a blog on the Internet.


You can install nginx, MariaDB, PHP and all the required PHP extensions with the following command:

$ apt-get install nginx mariadb-server php php-curl php-mysql php-gd php-intl php-mbstring php-soap php-xml php-xmlrpc php-zip php-fpm -y

Once the LEMP server is installed, start the Nginx and MariaDB service with the following command:

$ systemctl start nginx
$ systemctl start mariadb


Nginx's inbuilt features includes:

  • Nginx is built to work on low memory usage.
  • It can support extremely high concurrency.
  • Is Ipv6 enabled.
  • Supports reverse proxy with efficient caching.
  • Provides an inbuilt load balancer.
  • Supports WebSockets.
  • Optimized handling of index files, static files and provides auto indexing.
  • Is accompanied with FastCGI for efficient caching.



This article covers how to create a user with sudo privileges. You can now log in to your Ubuntu server with this user account and use sudo to run administrative commands.

Basically, The sudo command provides a mechanism for granting administrator privileges, ordinarily only available to the root user, to normal users. 



This article covers how to clear the cache and buffer memory of the physical memory along with clearing the swap space when needed.

Every Linux System has three options to clear cache without interrupting any processes or services.


If you want to clear Swap space, you may like to run the below command.

$ swapoff -a && swapon -a


To Clear PageCache, dentries and inodes:

$ sync; echo 3 > /proc/sys/vm/drop_caches


To Clear PageCache only:

$ sync; echo 1 > /proc/sys/vm/drop_caches


To Clear dentries and inodes:

$ sync; echo 2 > /proc/sys/vm/drop_caches



This article covers methods to install WordPress on Ubuntu Linux System. WordPress is undoubtedly one of the most popular Content Management Systems (CMS) available in the market. You can easily install WordPress on Ubuntu 18.04 because it is configured to work with Apache or NGINIX, MySql, PHP in a LAMP or a LEMP stack. 

It also features an extensive plugin framework, and theme system that allows site owners to use the simple and powerful publishing tools.


To Configure Maximum File Size Upload Setting to Allow Larger Files on Ubuntu:

By default, PHP restricts web uploads to under two megabytes.

To allow larger file uploads through the web interface, configure the upload_max_filesize setting in php.ini:

Apache: /etc/php/7.2/apache2/php.ini.
NGINX: /etc/php/7.2/fpm/php.ini.

; Maximum allowed size for uploaded files.

; http://php.net/upload-max-filesize

upload_max_filesize = 2M



This article covers how to install and configure the Memcached caching server on CentOS 8 system through the command-line tool.

Now, you can easily install and configure the Memcached server on your CentOS 8 system easily. 

Memcached is a free and open-source high-performance in-memory key-value data store.

Typically, it used as a caching system to speed up applications by caching various objects from the results of database calls.


To install memcached on CentOS, perform the following tasks as a user with root privileges:

1. Install memcached and its dependencies:

$ yum -y update
$ yum install -y libevent libevent-devel
$ yum install -y memcached
$ yum install -y php-pecl-memcache

2. Change the memcached configuration setting for CACHESIZE and OPTIONS:

i. Open /etc/sysconfig/memcached in a text editor.

ii. Locate the value for CACHESIZE and change it to at least 1GB. For example

CACHESIZE="1GB"

iii. Locate the value for OPTIONS and change it to localhost or 127.0.0.1

3. Save your changes to memcached and exit the text editor.

4. Restart memcached.

$ service memcached restart

5. Restart your web server.

For Apache:

$ service httpd restart



This article covers the different methods through which you can install the Speedtest utility on your CentOS 8 system. 

Also, we have also shown how to test the internet speed through the Speedtest-cli utility and how to generate URLs to share with others.


To Install Speedtest-cli on CentOS 8:

1. Open the terminal to make sure that Python is installed and working properly. Type the following command to check Python version:

$ python --version

If python is not installed on your system then first you will install python on your system. 

For this purpose, you need to run the below-mentioned command on the terminal to install python on CentOS 8.

$ sudo yum install python2

2. Download the speedtest_cli.py file using 'wget' command:

$ wget -O speedtest-cli https://raw.githubusercontent.com/sivel/speedtest-cli/master/speedtest.py

After successfully saved the downloaded file, you will type the following command on the terminal:

$ chmod +x speedtest-cli



This article covers how to download, configure, and install Moodle powered by the LAMP stack on RHEL 8.

Moodle is the world’s most popular learning management system for building robust online learning sites.

How to open HTTP and HTTPS for Moodle Learning Platform in CentOS 8 ?
To open HTTP and HTTPS services in the firewall to allow traffic to the NGINX web server, run the commands below:

# firewall-cmd --permanent --zone=public --add-service=http 
# firewall-cmd --permanent --zone=public --add-service=https

# firewall-cmd --reload



This article covers how to run Xrdp over Xorg protocol, which far most secure and recommended over the XVNC protocols.
Also, we covered the sessions manager that how you can manage your remote connections by tweaking its configuration parameters which sometimes come in a challenging phase.



This article covers how to install Tig on your Ubuntu 20.04 system and hence interacting with Git all the more efficiently.
However, you can get rid of this utility any time you want by following the uninstallation procedure that we have shared with you in this guide.
Tig is a text-mode interface for git. It mainly serves as a Git repository browser. It can also assist in staging changes for commit at the chunk level.

Features of Tig:
1. Browses the commits in the current branch
2. Displays the commits for one or more specific branches
3. Compares two branches
4. Helps to see the changes for a single file
5. Displays the list of stashes
6. Shows references for branches, tags and remotes

To install tig on Ubuntu:
1. First update the system, run:

# sudo apt update

2. To install tig on ubuntu, run:

# sudo apt install tig


To uninstall tig on Ubuntu:
To completely remove tig from your Ubuntu machine, type;

# sudo apt remove tig -y



This article covers how to install the AWS CLI very conveniently on your Linux Mint 20 system and use it for managing the Amazon Web Services very efficiently.
The AWS or Amazon Web Service command line interface is a command line tool for manage our Amazon web services.
AWS CLI provides direct access to the Amazon Web Services public API.
As it is a command line tool, it can also be used to create scripts to automate your Amazon web services.

To the AWS CLI on Ubuntu With APT:
1. First we update the package listing cache with the following command in the terminal (Ctrl + Alt + T):

# sudo apt-get update

2. Now we are going to install the AWS CLI using the command:

# sudo apt-get install awscli

3. We will can check if AWS CLI is working correctly with the following command:

# aws --version



This article covers the different methods to perform the installation of NodeJS on the CentOS 8 system.

Now that NodeJS is installed on your CentOS 8 system, you can use it to deploy a NodeJS application on the system.
Node.js is a cross-platform, runtime environment that was built on Chrome's JavaScript. This environment is designed to execute JavaScript code on the server-side.

To check Node version number, run the command:

# node --version



This article covers how to setup an SSH key-based authentication as well how to connect to your Linux server without entering a password.
To set up a passwordless SSH login in Linux all you need to do is to generate a public authentication key and append it to the remote hosts ~/.ssh/authorized_keys file.

To Disable SSH Password Authentication
To add an extra layer of security to your server you can disable the password authentication for SSH.
Before disabling the SSH password authentication make sure you can log in to your server without a password and the user you are logging in with has sudo privileges.
The following steps describe how to configure sudo access:
1. Log into your remote server with SSH keys, either as a user with sudo privileges or root:

# ssh sudo_user@server_ip_address

2. Open the SSH configuration file /etc/ssh/sshd_config, search for the following directives and modify as it follows:

/etc/ssh/sshd_config
PasswordAuthentication no
ChallengeResponseAuthentication no
UsePAM no

3. Once you are done save the file and restart the SSH service.
On Ubuntu or Debian servers, run the following command:

# sudo systemctl restart ssh

On CentOS or Fedora servers, run the following command:

# sudo systemctl restart sshd



This article covers how to install atom editor on CentOS 8 using the command-line application.

Atom is a free and open-source text and source code editor for OS X, Linux, and Windows with support for plug-ins written in Node.js, and embedded Git Control, developed by GitHub

To install latest version of Atom using .rpm package on your CentOS 8 machine:
1. First, go to the Atom official website and download the Atom .rpm package:

# sudo curl -SLo atom.x86_64.rpm  https://atom.io/download/rpm

2. You can now install Atom using dnf command:

# sudo dnf localinstall atom.x86_64.rpm

3. Now that Atom is installed on your CentOS system you can launch it from the command line by typing atom or by clicking on the Atom icon (Applications -> Programming -> Atom).



This article covers how to install the latest Gradle version on CentOS 8 system. 

Also you will learn how to set up the environment variable in the Gradle configuration file.

Gradle is an open-source build automation system.

It supports multiple programming languages such as Java, C++, and Python development. It is based on the concepts of Apache Ant and Apache Maven.


To verify if Gradle is installed properly use the gradle -v command which will display the Gradle version:

# gradle -v




This article covers how to install the RPM package on the CentOS 8 system.

Now you can easily download, install, update and erase Rpm packages on your CentOS system.
While working in Linux, you may have seen downloadable files with the .rpm extension.
Rpm files are designed to be downloaded and installed independently, outside of a software repository.
RPM Package Manager (RPM) is a free and open-source package management system for installing, uninstalling and managing software packages in Linux.

How to Download RPM Installation File on Linux ?
1. To install wget in CentOS, enter the following in a terminal window:

$ sudo yum install wget

2. To install weget in Fedora, enter the following:

$ sudo dnf install wget

3. Now, you can use the wget command to download the .rpm file you want.

Enter the following:

$ wget http://some_website/sample_file.rpm


To check the .rpm file for dependencies using the following command:

# sudo rpm –qpR sample_file.rpm

The system should list all the dependencies:
i. –q – This option tells RPM to query the file
ii. –p – This option lets you specify the target package to query
iii. –R – This lists the requirements for the package


How to install a .rpm file to your Linux CentOS or Fedora system ?
You can use the yum package manager to install .rpm files.
Enter the following:

# sudo yum localinstall sample_file.rpm

The localinstall option instructions yum to look at your current working directory for the installation file.



This article covers how to install the flameshot application on CentOS 8.

You will also learn how you can remove it from your CentOS 8 if you don’t need more on your system.

Main features of flameshot includes:
1. Supports graphical and CLI mode.
2. Edit images instantly.
3. Image uploads to Imgur.
4. Export and import configuration.
5. Easy to use and customizable.

To Install Flameshot in Linux:
Flameshot can be installed using package managers. Before installing through this method make sure you verify the version that ships with your OS:

$ sudo dnf install flameshot  # Rhel, Centos, Fedora
$ sudo apt install flameshot  # Debian, Ubuntu-based distro 

OR
# Ubuntu based distribution

$ wget https://github.com/flameshot-org/flameshot/releases/download/v0.9.0/flameshot-0.9.0-1.ubuntu-20.04.amd64.deb
$ dpkg -i flameshot-0.9.0-1.ubuntu-20.04.amd64.deb

# Rhel based distribution

$ wget https://github.com/flameshot-org/flameshot/releases/download/v0.9.0/flameshot-0.9.0-1.fc32.x86_64.rpm
$ rpm -i flameshot-0.9.0-1.fc32.x86_64.rpm



This article covers how you can easily change the sudo password timeout by adding a single entry in the sudoers file. If you are using Vi instead of Nano, follow the instructions described here.
You use sudo for some command in the terminal, it asks for the password.

You enter the password, the command runs.
For the subsequent commands, even if they need superuser privileges, you don't need to enter the password again.
After a certain amount of time, when you try to use sudo, it asks for the password again.
It happens because there is a default timeout in Ubuntu and other Linux system for Sudo. In Ubuntu, this default sudo timeout is 15 minutes.
If you think 15 minute is too short or too long you can even change the sudo password timeout in Ubuntu.

To Change sudo password timeout in Ubuntu:
1. Open a terminal (Ctrl+Alt+T) and use the following command:

$ sudo visudo

It will open a file in nano text editor that contains some settings related to sudo.
In here look for the following line:

Defaults        env_reset

Replace above line with this one:

Defaults        env_reset, timestamp_timeout=XX

Where XX is the new timeout value in minutes.
Of course you have to replace the XX with the desired timeout value.
2. Once you are done changing the default sudo password timeout, use Ctrl+X to exit the editor.
It will give you option to save or cancel the changes.

Use Y to save the changes.



This article covers how you can install Jenkins on Ubuntu OS. For further information about Jenkins, visit its official documentation.

Jenkins is an open-source automation server that can be used to easily set up continuous integration and continuous delivery (CI/CD) pipelines.

Continuous integration (CI) is a DevOps practice in which team members regularly commit their code changes to the version control repository, after which automated builds and tests are run. 

Continuous delivery (CD) is a series of practices where code changes are automatically built, tested, and deployed to production.


To install Jenkins on Ubuntu 20.04 as a standalone service:

1. Run the following commands as root or user with sudo privileges or root to install OpenJDK 11:

$ sudo apt update
$ sudo apt install openjdk-11-jdk

2. Once the installation is complete, verify it by checking the Java version:

# java -version

3. Import the GPG keys of the Jenkins repository using the following wget command:

# wget -q -O - https://pkg.jenkins.io/debian/jenkins.io.key | sudo apt-key add -

4. Next, add the Jenkins repository to the system with:

# sudo sh -c 'echo deb http://pkg.jenkins.io/debian-stable binary/ > /etc/apt/sources.list.d/jenkins.list'

5. Once the Jenkins repository is enabled, update the apt package list and install the latest version of Jenkins by typing:

# sudo apt update
# sudo apt install jenkins

6. Jenkins service will automatically start after the installation process is complete. You can verify it by printing the service status:

# systemctl status jenkins



This article covers how to install the VS code package on CentOS 8 using the command line application. Visual Studio Code is a free and open-source, cross-platform IDE or code editor that enables developers to develop applications and write code using a myriad of programming languages such as C, C++, Python, Go and Java to mention a few.


To Install Visual Studio Code on Debian, Ubuntu and Linux Mint:

1. Update your system by running the command.

$ sudo apt update

2. Once updated, proceed and install dependencies required by executing.

$ sudo apt install software-properties-common apt-transport-https

3. Next, using the wget command, download the repository and import Microsoft’s GPG key as shown:

$ wget -qO- https://packages.microsoft.com/keys/microsoft.asc | gpg --dearmor > packages.microsoft.gpg
$ sudo install -o root -g root -m 644 packages.microsoft.gpg /etc/apt/trusted.gpg.d/
$ sudo sh -c 'echo "deb [arch=amd64 signed-by=/etc/apt/trusted.gpg.d/packages.microsoft.gpg] https://packages.microsoft.com/repos/vscode stable main" > /etc/apt/sources.list.d/vscode.list'

4. Once you’ve enabled the repository, update the system and install Visual Studio Code by running the command:

$ sudo apt update
$ sudo apt install code



This article covers how you can copy and paste text in the Linux Terminal. This saves the time that spends in typing the long commands and text.

When you enter a long command into the Terminal window that you found on the web or in a document, you can save yourself some time by easily copying and pasting the command at the prompt.


To Copy and Paste Text into the Linux Terminal:

1. To begin, highlight the text of the command you want on the webpage or in the document you found. 

2. Press Ctrl + C to copy the text.

3. Press Ctrl + Alt + T to open a Terminal window, if one is not already open. Right-click at the prompt and select "Paste" from the popup menu.

4. The text you copied is pasted at the prompt. 

5. Press Enter to execute the command.

6. You can also copy text from the Terminal window to paste into other programs. 

7. Simply highlight the text, right-click on it, and select "Copy" from the popup menu. 

You can paste this text into a text editor, word processor, and so on.



This article covers CouchDB installation on CentOS Linux System. 

Apache CouchDB is an open-source database management system, developed by Apache Software Foundation. It is a NoSQL document-store database developed in ErLang.

CouchDB uses multiple formats and protocols to store, transfer, and process its data, it uses JSON (JavaScript Object Notation) to store data, JavaScript as its query language using MapReduce, and HTTP for an API.

Unlike a relational database, a CouchDB database does not store data and relationships in tables. Instead, each database is a collection of independent documents. Each document maintains its own data and self-contained schema.

CouchDB software includes a native web interface i.e. Fauxton for administration of CouchDB database server.


To Install CouchDB Yum Repository on CentOS 8:

1. Create a repo file by using vim editor.

# vi /etc/yum.repos.d/bintray-apache-couchdb-rpm.repo

2. And add following directives in this file.

[bintray--apache-couchdb-rpm]
name=bintray--apache-couchdb-rpm
baseurl=http://apache.bintray.com/couchdb-rpm/el$releasever/$basearch/
gpgcheck=0
repo_gpgcheck=0
enabled=1

3. Build cache for newly installed yum repositories.

# dnf makecache

4. Now we can install CouchDB software by using dnf command.

# dnf install -y couchdb



This article covers how to install and configure Ansible on Ubuntu 20.04. Ansible is a widely used automation tool in DevOps and used by thousands of developers and sysadmins to configure and deploy applications on servers.

It saves time and minimizes the effort required to handle a multitude of servers in a complex IT infrastructure. 


To install Ansible on Ubuntu:

1. First, refresh your system’s package index with:

# sudo apt update

2. Following this update, you can install the Ansible software with:

$ sudo apt install ansible

Press Y when prompted to confirm installation.


To check if Ansible is able to connect to these servers and run commands via SSH:

From your local machine or Ansible control node, run:

$ ansible all -m ping -u root

This command will use Ansible's built-in ping module to run a connectivity test on all nodes from your default inventory, connecting as root.

The ping module will test:

i. if hosts are accessible;

ii. if you have valid SSH credentials;

iii. if hosts are able to run Ansible modules using Python.



This article covers how to install and use Mono on CentOS 8 system. Mono is a platform for developing and running cross-platform applications based on the ECMA/ISO Standards. 

It is a free and open-source implementation of Microsoft’s .NET framework.


To Verify the installation by running the following command that prints the Mono version:

$ mono --version



This article covers the installation of Fail2ban and the configuration of an sshd filter. There are so many options to configure but we focused on the basic ones. Feel free to peruse the Fail2ban man pages by running man fail2ban to discover what more you can do with it.

Fail2ban is a free, open-source and widely used intrusion prevention tool that scans log files for IP addresses that show malicious signs such as too many password failures, and much more, and it bans them (updates firewall rules to reject the IP addresses). 

By default, it ships with filters for various services including sshd.


To install  and configure Fail2ban on CentOS/RHEL 8:

1. After logging into your system, access a command-line interface, then enable the EPEL repository on your system:

# dnf install epel-release

OR

# dnf install https://dl.fedoraproject.org/pub/epel/epel-release-latest-8.noarch.rpm

2. Afterward, install the Fail2ban package by running the following command:

# dnf install fail2ban

3. To start and enable the fail2ban service for now and check if it is up and running using the following systemctl command:

# systemctl start fail2ban
# systemctl enable fail2ban
# systemctl status fail2ban



This article covers the installation of the LAMP stack (i.e., Linux, Apache, MariaDB, and PHP) on RHEL 8.

LAMP stands for Linux, Apache, MariaDB/MySQL and PHP, all of which are open source.


With the yum commands below, install LAMP stack:

# Will automatically update

$ sudo yum -y update

# Will automatically install Apache/HTTPD

$ sudo yum -y install httpd


To Install MariaDB Database Server on CentOS 8/RHEL 8:

1. Enter the following command to install MariaDB on CentOS 8/RHEL 8.

# dnf install mariadb-server mariadb -y

2. After it's installed, we need to start it.

# systemctl start mariadb

3. Enable auto start at system boot time.

# systemctl enable mariadb

4. Check status:

# systemctl status mariadb



This article covers how to install and use the Docker-compose on CentOS 8 system. By using the Docker-compose, you can deploy multiple Docker applications with container services through a single command. 

Basically, Docker Compose is a tool that can be used to define and run multiple containers as a single service. With Docker Compose, you can link multiple containers and deploy an application from a single command. 

It is mainly used in the development, testing and staging environment. 

Docker Compose uses a YAML file to define a complex stack in a file and running it with a single command.


To install Docker on CentOS:

1. Before starting, make sure you have Docker installed on your server. If not installed, you will need to add Docker-CE repository to your system. 

You can add it with the following command:

$ dnf config-manager --add-repo=https://download.docker.com/linux/centos/docker-ce.repo

2. Once the repository is added, install the latest version of docker using the following command:

# dnf install docker-ce --nobest -y
# systemctl start docker
# systemctl enable docker

3. You can verify the docker version with the following command:

$ docker --version



This article covers how to install ansible AWX on Ubuntu 20.04. You have got a basic idea about managing hosts, inventories, and projects from AWX ansible.

Ansible AWX is an open source tool which provides a web-based user interface, REST API, and task engine for easy and collaborative management of Ansible Playbooks and Inventories.

AWX allows you to centrally manage Ansible playbooks, inventories, Secrets, and scheduled jobs from a web interface. 


To Install Ansible on Ubuntu:

Run the following commands,

# sudo apt update
# sudo apt install ansible



This article covers how to add a user to sudoers using different methods, limit root access with sudo and remove a user from sudoers.

Sudo is a very handy tool for system administrators that allow them to provide root access to a user with granularity.


Steps to Add Sudo User on Ubuntu ?

1. Log into the system with a root user or an account with sudo privileges.

2. Open a terminal window and add a new user with the command:

# adduser newuser

The adduser command creates a new user, plus a group and home directory for that user.

You may get an error message that you have insufficient privileges. (This typically only happens for non-root users.) Get around it by entering:

# sudo adduser newuser

3. You can replace newuser with any username you wish. The system will add the new user; then prompt you to enter a password. Enter a great secure password, then retype it to confirm.


To Add User to Sudo Group:

1. In a terminal, enter the command:

# usermod -aG sudo newuser

Replace newuser with the username that you entered in Step 1.

Again, if you get an error, run the command with sudo as follows:

# sudo usermod -aG sudo newuser

The -aG option tells the system to append the user to the specified group. (The -a option is only used with G).



This article covers how to install Apache OpenOffice on CentOS 8. Apache OpenOffice is a software bundle which contains various software tools like word processor, spreadsheet, database management, and so on. It is very much similar to other popular editors like Libreoffice and NeoOffice. 


Main features and tools provided by OpenOffice:

1. Writer a word processor you can use for anything from writing a quick letter to producing an entire book.

2. Calc a powerful spreadsheet with all the tools you need to calculate, analyze, and present your data in numerical reports or sizzling graphics.

3. Impress the fastest, most powerful way to create effective multimedia presentations.

4. Draw lets you produce everything from simple diagrams to dynamic 3D illustrations.

5. Base lets you manipulate databases seamlessly. Create and modify tables, forms, queries, and reports, all from within Apache OpenOffice.

6. Math lets you create mathematical equations with a graphic user interface or by directly typing your formulas into the equation editor.



This article covers MongoDB installation on CentOS 8 system.

Instead, it uses JSON-like documents with dynamic schemas, meaning that, unlike relational databases, MongoDB does not require a predefined schema before you add data to a database. 

You can alter the schema at any time and as often as is necessary without having to set up a new database with an updated schema.


How to Start the MongoDB Service and Test the Database on Ubuntu?

1. Run the following systemctl command to start the MongoDB service:

# sudo systemctl start mongod

2. Then check the service's status:

# sudo systemctl status mongod

This command will return output like the following, indicating that the service is up and running

3. After confirming that the service is running as expected, enable the MongoDB service to start up at boot:

# sudo systemctl enable mongod


How to Managing the MongoDB Service on Ubuntu?

1. The systemctl status command checks the status of the MongoDB service:

# sudo systemctl status mongod

2. You can stop the service anytime by typing:

# sudo systemctl stop mongod

3. To start the service when it’s stopped, run:

# sudo systemctl start mongod

4. You can also restart the server when it’s already running:

# sudo systemctl restart mongod

5. If you ever wish to disable this automatic startup, type:

# sudo systemctl disable mongod

6. Then to re-enable it to start up at boot, run the enable command again:

# sudo systemctl enable mongod



This article covers how to perform Docker installation and Configuration. Also, you will learn how to install Docker CE on the CentOS 8 system. Docker container technology allows you to run applications in a specific and isolated environment.

Docker Community Edition (CE) is the new name for the free Docker product.

To Install Docker CE on Linux:
1. Remove all existing docker applications (that might currently be installed) in order to make sure we are using a clean installation.:

# yum remove docker docker-client docker-client-latest docker-common docker-latest docker-latest-logrotate docker-logrotate docker-engine

2. Add an external repository that will help us obtain the Docker software:

# dnf config-manager --add-repo=https://download.docker.com/linux/centos/docker-ce.repo

3. Check what versions of docker we have in the repository:

# dnf list docker-ce

4. Install the version that best matches our CentOS server version:

# dnf install docker-ce --nobest

5. We can double-check if the installation was successful by using the version command:

# docker -v



This article covers how  to setup Gitlab on CentOS Linux.

Gitlab is an application tool that is used for source code management. It allows you to plan your development process; code, and verify; package software, and release it with an in-built continuous delivery feature; automate configurations management, and monitor software performance.


To be able to access the GitLab interface you'll need to open ports 80 and 443. 

To do so run the following commands:

$ sudo firewall-cmd --permanent --zone=public --add-service=http
$ sudo firewall-cmd --permanent --zone=public --add-service=https
$ sudo firewall-cmd --reload



To install Postfix service to send notification emails, and enable it to start at system boot, then check if it is up and running using following commands:

# yum install postfix
# systemctl start postfix
# systemctl enable postfix
# systemctl status postfix



This article covers how to install and configure Netdata on Ubuntu 20.04 LTS and different metrics visualized in it. Netdata provides an excellent solution for monitoring your single node in real-time. You can configure alarms and notifications which can be triggered when a certain event or threshold is exceeded.


To install Netdata on Ubuntu:

1. You can install netdata on Ubuntu by running the following commands.

$ sudo apt update 
$ sudo apt install netdata 

Press 'y' if confirmation prompted by the installer.

2. Edit netdata configuration file in your favorite text editor.

$ sudo vim /etc/netdata/netdata.conf 

3. After modifying its configuration file, you can Save your file and restart netdata service:

$ sudo systemctl restart netdata 



This article covers how to Install MySQL Version 8 on Red Hat Enterprise Linux 8. Now, you should now have a fully functioning MySQL server version 8 running on your Server.


To Install MySQL 8.0 On CentOS 8 / RHEL 8:

1. Install MySQL 8.0 from MySQL Dev Community

Add the official repository of MySQL to install the MySQL community server:

$ rpm -ivh https://dev.mysql.com/get/mysql80-community-release-el8-1.noarch.rpm

Make sure the MySQL repository has been added and enabled by using the following command:

$ yum repolist all | grep mysql | grep enabled


To Manage MySQL server Service on Linux:

1. After the installation of MySQL, start MySQL server service using the following command:

$ systemctl start mysqld

2. The below command will Enable MySQL server at system startup:

$ systemctl enable mysqld

3. Verify that MySQL server is started using the following command:

$ systemctl status mysqld



This article covers how to secure Red Hat Enterprise Linux 8 with UFW. UFW may not be intended to provide complete firewall functionality, but it does provide an easy way to create and manage simple firewall rules.

A firewall is a way to protect machines from any unwanted traffic from outside. 

It enables users to control incoming network traffic on host machines by defining a set of firewall rules. 

These rules are used to sort the incoming traffic and either block it or allow through.

Note that firewalld with nftables backend does not support passing custom nftables rules to firewalld, using the --direct option.


How to start, stop, restart firewalld service on an RHEL 8?

By now you know about firewalld zones, services, and how to view the defaults. It is time to activate and configure our firewall.

1. Start and enable firewalld

$ sudo systemctl start firewalld
$ sudo systemctl enable firewalld

2. Stop and disable firewalld

$ sudo systemctl stop firewalld
$ sudo systemctl disable firewalld

3. Check the firewalld status

$ sudo firewall-cmd --state

4. Command to reload a firewalld configuration when you make change to rules

$ sudo firewall-cmd --reload

5. Get the status of the firewalld service

$ sudo systemctl status firewalld


When to use firewalld, nftables, or iptables:

1. firewalld: Use the firewalld utility for simple firewall use cases. The utility is easy to use and covers the typical use cases for these scenarios.

2. nftables: Use the nftables utility to set up complex and performance critical firewalls, such as for a whole network.

3. iptables: The iptables utility on Red Hat Enterprise Linux 8 uses the nf_tables kernel API instead of the legacy back end. 

The nf_tables API provides backward compatibility so that scripts that use iptables commands still work on Red Hat Enterprise Linux 8. For new firewall scripts, Red Hat recommends to use nftables.



This article covers LibreOffice installation on CentOS 8 distribution. LibreOffice is a powerful and open-source office suite that can be used on Linux, Mac as well as on Windows.

It provides various features such as word documentation, spreadsheets, data processing, drawing, presentation design, Math calculation, and more.


How to uninstall Old LibreOffice or OpenOffice Versions ?

If any previously installed LibreOffice or OpenOffice versions you have, remove it using following command.

# yum remove openoffice* libreoffice* [on RedHat based Systems]
$ sudo apt-get remove openoffice* libreoffice*	[On Debian based Systems]



This article covers the complete installation guide of VirtualBox on the CentOS 8 system.

Oracle VirtualBox is a virtualization software solution that allows you to create and run virtual machines on a single hardware machine.

With VirtualBox, your existing operating system stays unaffected by the virtual environment.


To Start VirtualBox on Linux:

Use the command:

$ VirtualBox

The VirtualBox manager interface will prompt you.

Alternatively, you can use the graphical interface and access the application:

Application >> System Tools >> Oracle VM VirtualBox



This article covers how to flush the DNS cache on Ubuntu. If the sites are not loading properly or you are receiving outdated sites, try to flush the DNS cache to see if the issue resolves. 

Remember, after the DNS cache is flushed, sites will first load slightly slower. 

But once the DNS cache is re-populated, sites will be loaded faster.


Facts about flushing DNS cache on Ubuntu:

1. DNS cache is a temporary database that stores information about previous DNS lookups. 

2. Whenever you visit a website, your OS and web browser will keep a record for the domain and the corresponding IP address. 

3. Flushing DNS cache eliminates the need for repetitive queries to the remote DNS servers and allows your OS or browser to resolve the website's URL quickly.


How to use dns-clean to flush DNS-Cache ?

You can clear the DNS cache is by starting the dns-clean utility. Run the following command in your Terminal to do so:

$ sudo /etc/init.d/dns-clean start



This article covers how you can download YouTube videos on Linux using the youtube-dl utility. The youtube-dl is a handy utility with a large feature set. However, there is a lot more you can do with this utility. To explore more features, visit its official documentation . To play the downloaded videos, you can use any media players like VLC , FFmpeg , and so on.

youtube-dl is a command-line program that lets you easily download videos and audio from more than a thousand websites. 


youtube-dl is a Python based small command-line tool that allows to download videos from YouTube.com, Dailymotion, Google Video, Photobucket, Facebook, Yahoo, Metacafe, Depositfiles and few more similar sites. 

It written in pygtk and requires Python interpreter to run this program, it's not platform restricted. It should run on any Unix, Windows or in Mac OS X based systems.


To Install YouTube-DL in RHEL/CentOS and Fedora:

The youtube-dl program can be installed by enabling epel repository under your systems. Once enabled, you can install using 'yum' package manager tool:

$ yum install youtube-dl

Also, if you wish to add any third party repository, you can still install it right away using curl or wget command:

$ curl https://yt-dl.org/latest/youtube-dl -o /usr/local/bin/youtube-dl

OR

$ wget https://yt-dl.org/downloads/latest/youtube-dl -O /usr/local/bin/youtube-dl

Your system must have curl or wget packages installed to fetch the recent version youtube-dl file. If you don't have them, you may yum to get it.

After fetching the file, you need to set a executable permission on the script to execute properly:

$ chmod a+rx /usr/local/bin/youtube-dl


To Install YouTube-DL in Ubuntu/Linux Mint and Debian:

$ sudo add-apt-repository ppa:nilarimogard/webupd8
$ sudo apt-get update
$ sudo apt-get install youtube-dl

Also, instead using any third party PPA, you can use curl or wget command to install latest version of youtube-dl script:

$ sudo curl https://yt-dl.org/latest/youtube-dl -o /usr/local/bin/youtube-dl

OR

$ sudo wget https://yt-dl.org/downloads/latest/youtube-dl -O /usr/local/bin/youtube-dl

After downloading the script, set the executable permission:

$ sudo chmod a+rx /usr/local/bin/youtube-dl


To Update YouTube-DL,

Youtube-dl itself can be updated to the latest version using the following command:

$ youtube-dl -U



This article covers how to install Cockpit on Ubuntu 20.04 system. Cockpit is a free and open source web console tool for Linux administrators and used for day to day administrative and operations tasks. 


To Install the Cockpit package on Ubuntu 20.04 LTS Server, run the command:

$ sudo apt update
$ sudo apt install cockpit -y

Once cockpit package is installed successfully then start its service using the following systemctl command,

$ sudo systemctl start cockpit

Run the following to verify the status of cockpit service,

$ sudo systemctl status cockpit


Features of Cockpit:

Cockpit allows you to perform:

1. Service Management – Start, stop, restart, reload, disable, enable, mask e.t.c

2. User Account Management – Add users, delete, Lock, assign Administrator role, set password, force password change, Add Public SSH keys e.t.c.

3. Firewall Management

4. Cockpit Container management

5. SELinux Policy management

6. Journal v2

7. iSCSI Initiator configurations

8. SOS-reporting

9. NFS Client setup

10. Configure OpenConnect VPN Server

11. Privileged Actions – Shutdown, Restart system

12. Join Machine to Domain

13. Hardware Device Management

14. System Updates for dnf, yum, apt hosts

15. Manage the Kubernetes Node



This article covers how to install XAMPP on your CentOS system. XAMPP is an easy to install and use Apache distribution packaged with MariaDB, PHP, and Perl.

XAMPP was first developed by a project team called Apache Friends. As an open-source Apache distribution of a PHP development environment, it consists of cross-platform software (X): Apache (A), MariaDB (M), PHP (P) and Perl (P). 


To install XAMPP on CentOS 8 Linux system:

1. Update system

Ensure your CentOS system is updated.

$ sudo dnf -y update
$ sudo dnf -y install libnsl

2. Download XAMPP on CentOS 8

Install wget on CentOS 8:

$ sudo dnf -y install wget

Download XAMPP installer. Choose the installer matching the PHP version you want to have.

### PHP 8.0 ###

$ wget https://www.apachefriends.org/xampp-files/8.0.1/xampp-linux-x64-8.0.1-0-installer.run

### PHP 7.4 ###

$ wget https://www.apachefriends.org/xampp-files/7.4.14/xampp-linux-x64-7.4.14-0-installer.run

### PHP 7.3 ###

$ wget https://www.apachefriends.org/xampp-files/7.3.26/xampp-linux-x64-7.3.26-0-installer.run

3. The binary installer should be executable.

### PHP 8.0 ###

$ chmod a+x xampp-linux-x64-8.0.1-0-installer.run

### PHP 7.4 ###

$ chmod a+x xampp-linux-x64-7.4.14-0-installer.run

### PHP 7.3 ###

$ chmod a+x xampp-linux-x64-7.3.26-0-installer.run

4. Then run the XAMP installer:

### PHP 8.0 ###

$ sudo ./xampp-linux-x64-8.0.1-0-installer.run

### PHP 7.4 ###

$ sudo ./xampp-linux-x64-7.4.14-0-installer.run

### PHP 7.3 ###

$ sudo ./xampp-linux-x64-7.3.26-0-installer.run


How to Start and use XAMPP on CentOS 8:

XAMPP is installed to /opt/lampp/. To start XAMPP services, run:

$ sudo /opt/lampp/lampp start

To verify installation of XAMPP on CentOS 8 visit the Apache web page:

http://localhost


Stopping and Uninstalling XAMPP on CentOS 8:

To stop XAMPP services run:

$ sudo /opt/lampp/lampp stop

To uninstall XAMPP on CentOS 8, run:

$ cd /opt/lampp
$ sudo ./uninstall
$ sudo rm-rf /opt/lampp



This article covers how you can install Memcached on Ubuntu 20.04. Memcached has proved to be a very reliable caching system since its inception in 2003 and continues to be a favorite among developers in speeding up web applications. 

Memcached is a high-performance, distributed memory object caching server. It is free and open source software intended for use in speeding up dynamic web applications by mitigating database load.


To install and configure memcached on Ubuntu:

1. Update your Ubuntu server:

$ sudo apt update
$ sudo apt upgrade

2. Install memcached server on Ubuntu:

Run apt command as follows:

$ sudo apt install memcached

3. Configure memcached server:

Edit config file named /etc/memcached.conf using a text editor such as nano command or vim command:

$ sudo nano /etc/memcached.conf

OR

$ sudo vi /etc/memcached.conf


How to restart, stop, reload memcached server on Ubuntu:

To Stop service - $ sudo systemctl stop memcached

To start Service - $ sudo systemctl start memcached

To restart Service - $ sudo systemctl restart memcached

To check the status - $ sudo systemctl status memcached



This article covers method to Install and Use Firewalld in CentOS in order to increase the security of your Linux system. Note that the host-based firewall like firewalld is recommended by compliances like PCI DSS. 

FirewallD is a complete firewall solution that manages the system's iptables rules and provides a D-Bus interface for operating on them. Starting with CentOS 7, FirewallD replaces iptables as the default firewall management tool.

Firewalld services are predefined rules that apply within a zone and define the necessary settings to allow incoming traffic for a specific service.


How to install Firewalld on CentOS?

Firewalld is installed by default on CentOS 7, but if it is not installed on your system, you can install the package by running the command:

$ sudo yum install firewalld

Firewalld service is disabled by default. You can check the firewall status with:

$ sudo firewall-cmd --state

If you just installed or never activated before, the command will print not running. Otherwise, you will see running.

To start the FirewallD service and enable it on boot type:

$ sudo systemctl start firewalld
$ sudo systemctl enable firewalld


To open HTTP and HTTPS ports add permanent service rules to the dmz zone:

$ sudo firewall-cmd --permanent --zone=dmz --add-service=http
$ sudo firewall-cmd --permanent --zone=dmz --add-service=https

Make the changes effective immediately by reloading the firewall:

$ sudo firewall-cmd --reload

Zones provided by FirewallD:

1. drop: All incoming connections are dropped without any notification. Only outgoing connections are allowed.

2. block: All incoming connections are rejected with an icmp-host-prohibited message for IPv4 and icmp6-adm-prohibited for IPv6n. Only outgoing connections are allowed.

3. public: For use in untrusted public areas. You do not trust other computers on the network, but you can allow selected incoming connections.

4. external: For use on external networks with NAT masquerading enabled when your system acts as a gateway or router. Only selected incoming connections are allowed.

5. internal: For use on internal networks when your system acts as a gateway or router. Other systems on the network are generally trusted. Only selected incoming connections are allowed.

6. dmz: Used for computers located in your demilitarized zone that have limited access to the rest of your network. Only selected incoming connections are allowed.

7. work: Used for work machines. Other computers on the network are generally trusted. Only selected incoming connections are allowed.

8. home: Used for home machines. Other computers on the network are generally trusted. Only selected incoming connections are allowed.

9. trusted: All network connections are accepted. Trust all of the computers in the network.



This article covers how to install sublime text editor on the CentOS 8 system through the terminal. Sublime text editor is quite similar to vim editor. Sublime text has a built-in Python API available in Windows, Linux, and Mac OS.


To install Sublime Text on Ubuntu:

1. Install the GPG key:

$ wget -qO - https://download.sublimetext.com/sublimehq-pub.gpg | sudo apt-key add -

2. Ensure apt is set up to work with https sources:

$ sudo apt-get install apt-transport-https

3. Select the channel to use:

i. Stable

$ echo "deb https://download.sublimetext.com/ apt/stable/" | sudo tee /etc/apt/sources.list.d/sublime-text.list

ii. Dev

$ echo "deb https://download.sublimetext.com/ apt/dev/" | sudo tee /etc/apt/sources.list.d/sublime-text.list

4. Update apt sources and install Sublime Text:

$ sudo apt-get update
$ sudo apt-get install sublime-text


To fix yum-config-manager command not found:

You need to Install yum-utils by running the command below:

$ yum install yum-utils



This article covers perform the installation of TeamPass using the LAMP stack on Ubuntu. Now you can easily manage your credentials within your Organization to save credentials and manage access to every individual. 

TeamPass is a Collaborative Passwords Manager used for managing passwords and sharing them among team members.


To Download Teampass on Ubuntu:

1. Start by cloning the Teampass repository to your web server root directory as shown below;

$ git clone https://github.com/nilsteampassnet/TeamPass.git /var/www/html/teampass

2. Set the ownership of the teampass web directory to web server user (www-data)

$ chown -R www-data.www-data /var/www/html/teampass/

3. Next, edit the /etc/php/7.2/apache2/php.ini configuration file and increase the script execution time from 30 to 60 secs.

vim /etc/php/7.2/apache2/php.ini
...
;max_execution_time = 30
max_execution_time = 60
...

4. Restart Apache web server

$ systemctl restart apache2


To Finalize TeamPass installation on Ubuntu:

Final installation of Teampass can be done from the browser. 

Hence, navigate to the browser and enter the Teampass server URL, 

http://Server_IP/teampass

This will redirect you to Teampass welcome page



This article covers how to install TeamViewer on the CentOS system. Additionally, you will learn how to install, launch, and update TeamViewer on CentOS.

We have also covered how to uninstall TeamViewer in case you no longer need it on your system. 

For some more help regarding TeamViewer, run teamviewer help in Terminal.

TeamViewer is a Robust cross-platform solution that provides secure remote access, remote control, and remote support solution across devices. 

The data traffic between devices are encrypted which makes the TeamViewer very secure. 

This software is available for “Linux, Windows, Mac, Chrome OS” and even for mobile devices like "iOS, Android, and so on".


To Install TeamViewer on CentOS 8:

1. Enable EPEL Repo on CentOS 8

You can install EPEL repo using the below command. This command will enable the repo if it is not already installed:

$ sudo yum install https://dl.fedoraproject.org/pub/epel/epel-release-latest-8.noarch.rpm -y

2. Now you can proceed further to install TeamViewer on CentOS 8:

$ sudo yum install teamviewer.x86_64.rpm -y

3. Once the package is installed you can start using team viewer:

$ teamviewer



This article covers how to install skype on the CentOS 8 system. One is using the RPM skype repository and another one is through the snap tool. 

Running Skype on CentOS/Fedora allows you to make Skype calls, group video calls, instant messaging, phone number calls, and screen sharing.


To Install Skype on CentOS:

1. Execute the command;

$ sudo yum localinstall skypeforlinux-64.rpm

2. Press y when prompted to confirm installation.


To Launch Skype on CentOS:

After successful installation, search Skype on your Desktop Environment search bar.



This article covers how to install Nginx on the Ubuntu system. Also, you will learn how to configure the firewall and manage Nginx services. 

Finally, you will see how to uninstall Nginx in case you no longer need it in your system.

Nginx is a free, open-source Linux application for web servers. It works as a reverse proxy server by directing web traffic to specific servers.

Also, Nginx is used for security and load-balancing, but can also function independently as a web server.


To Install Nginx From Ubuntu Repositories:

1. Update Software Repositories

It is important to refresh the repository lists before installing new software. This helps make sure that the latest updates and patches are installed.

Open a terminal window and enter the following:

$ sudo apt-get update

2. Nginx is included in the Ubuntu 20.04 default repositories. Install it by entering the following command:

$ sudo apt-get install nginx


How to manage Nginx on Ubuntu ?

The behavior of Nginx can be adjusted. Use this to start or stop Nginx, or to enable or disable Nginx at boot.

Start by checking the status of the Nginx service:

$ sudo systemctl status nginx

If the status displays active (running), Nginx has already been started. 

Press CTRL+z to exit the status display.

If Nginx is not running, use the following command to launch the Nginx service:

$ sudo systemctl start nginx

To set Nginx to load when the system starts, enter the following:

$ sudo systemctl enable nginx

To stop the Nginx service, enter the following:

$ sudo systemctl stop nginx

To prevent Nginx from loading when the system boots:

$ sudo systemctl disable nginx

To reload the Nginx service (used to apply configuration changes):

$ sudo systemctl reload nginx

For a hard restart of Nginx:

$ sudo systemctl restart nginx

To Test the Configuration

$ sudo nginx –t

The system should report that the configuration file syntax is OK, and that the configuration file test is successful.



This article covers how to install Apache web server on CentOS 8 distribution. With Apache we server, you can host web pages over the network. Apache is available within CentOS's default software repositories, which means you can install it with the dnf package manager.


To install Apache on CentOS:

1. Execute the command below to install the Apache package:

$ sudo dnf install httpd

After confirming the installation, dnf will install Apache and all required dependencies.

2. If you also plan to configure Apache to serve content over HTTPS, you will also want to open up port 443 by enabling the https service:

$ sudo firewall-cmd --permanent --add-service=https

3. Next, reload the firewall to put these new rules into effect:

$ sudo firewall-cmd --reload

After the firewall reloads, you are ready to start the service and check the web server.


To check your Apache Web Server:

1. Apache does not automatically start on CentOS once the installation completes, so you will need to start the Apache process manually:

$ sudo systemctl start httpd

2. Verify that the service is running with the following command:

$ sudo systemctl status httpd

You will receive an active status when the service is running.


To manage the Apache Process on CentOS:

Now that the service is installed and running, you can now use different systemctl commands to manage the service.

1. To stop your web server, type:

$ sudo systemctl stop httpd

2. To start the web server when it is stopped, type:

$ sudo systemctl start httpd

3. To stop and then start the service again, type:

$ sudo systemctl restart httpd

4. If you are simply making configuration changes, Apache can often reload without dropping connections. To do this, use this command:

$ sudo systemctl reload httpd

5. By default, Apache is configured to start automatically when the server boots. If this is not what you want, disable this behavior by typing:

$ sudo systemctl disable httpd

6. To re-enable the service to start up at boot, type:

$ sudo systemctl enable httpd

Apache will now start automatically when the server boots again.



This article covers how to assign multiple IP addresses to a single interface in Mint OS. By following our guide carefully, you can either assign the IP address temporarily or permanently to your network interface.

NIC stands for network interface controller or network interface (controller) card. WNIC is wireless network interface controller or wireless network interface (controller) card. IP Addresses belong to network interfaces, not to the computer itself.


To Restart network service using command:

# systemctl restart network

To Verify the new IP address using command:

# ip addr


How configure multiple IP address in CentOS ?

Now, in order to add additional IP addresses you'll need to edit the configuration file (from hereon called “config file”) for this specific interface. On CentOS 7, the interface config files are located in /etc/sysconfig/network-scripts/ and they are all prefixed with ifcfg-.


How remove secondary IP address Linux?

To add or remove additional IP adresses and keep the configuration persistent, we need to Edit the corresponding /etc/sysconfig/network-scripts/ifcfg-eth[x] configuration file and add/remove as many additional IPADDR[n] and PREFIX[n] entries as additional IP addresses are required.


To configure a static IP address on CentOS  / RHEL :

1. Create a file named /etc/sysconfig/network-scripts/ifcfg-eth0 as follows:

DEVICE=eth0.

BOOTPROTO=none.

ONBOOT=yes.

PREFIX=24.

IPADDR=your_ip_address

2. Restart network service: systemctl restart network.


How do I login as a different user in Linux?

To change to a different user and create a session as if the other user had logged in from a command prompt, type "su -" followed by a space and the target user's username. Type the target user's password when prompted.


What is Nmcli in Linux?

nmcli is a command-line tool which is used for controlling NetworkManager. nmcli commnad can also be used to display network device status, create, edit, activate/deactivate, and delete network connections. Typical Uses: Scripts: Instead of manually managing the network connections it utilize NetworkMaager via nmcli.


Difference between the output of ifconfig and ipconfig:

Functionality: The ipconfig command displays all the currently connected network interfaces whether they are active or not. 

On the other hand, the ifconfig command displays only the enabled network interfaces that are connected to the system.



This article covers how to install Zimbra mail server on CentOS & RHEL systems. Zimbra offers two editions, the commercially supported edition called 'Network Edition' & a free/open-source version called 'Open Source Edition'. 

Zimbra Collaboration Suite (ZCS) is a collaborative software suite that includes a mail & chat server with a web client.


Main components of Zimbra Mail and Collaboration Server are:

1. Zimbra Core: These are basic libraries, utilities, monitoring tools, and basic configuration files.

2. Zimbra LDAP: This has the OpenLDAP LDAP directory server that provides authentication and configs store for users and other zimbra components.

3. Zimbra MTA (mail routing server): Has Postfix mail transfer agent (MTA) that receives email via SMTP and routes each message to the appropriate Zimbra mailbox server using Local Mail Transfer Protocol (LMTP). It also includes the anti-virus and anti-spam components.

4. Zimbra Store (Zimbra server): The mailbox server includes Data store, Message store and Index store for the mailboxes on the server. When a mail arrives, the Zimbra server schedules a thread to have the message indexed in the index store.

5. Zimbra-SNMP: This is an optional component for for monitoring and it runs on every server (Zimbra server, Zimbra LDAP, Zimbra MTA). Swatch is used to watch the syslog output to generate SNMP traps.

6. Zimbra Logger: This is an optional component for the mailbox server. It installs tools for syslog aggregation, reporting, and message tracing. This is required for the message trace feature.


To Edit your hosts file on Ubuntu:

1. $ nano –w /etc/hosts

You should have this line

Ip_address server.domain.com server

Update it as per your server information.

2. Press ctrl key + o to save

3. Press ctrl key + x to exit

4. Restart your server to take effect all the changes

$ reboot


To install Zimbra on Ubuntu server:

1. Install Zimbra prerequisites

$ apt-get update 

$ apt-get install libgmp10 libperl5.18 libaio1 pax sysstat sqlite3

2. Download Zimbra Email Server

$ wget https://files.zimbra.com/downloads/8.6.0_GA/zcs8.6.0_GA_1153.UBUNTU14_64.20141215151116.tgz

3. Unpack the file

tar xzvf zcs-8.6.0_GA_1153.UBUNTU14_64.20141215151116.tgz

4. Go to Zimbra forder

cd zcs-8.6.0_GA_1153.UBUNTU14_64.20141215151116

5. Begin installation

./install.sh

NOTE : While running the install.sh command you will be prompted with the following questions.

Do you agree with the terms of the software license agreements? [N] Y

Install zimbra-ldap [Y] Enter

Install zimbra-logger [Y] Enter

Install zimbra-mta [Y] Enter

Install zimbra-dnscache [Y] N Enter

Install zimbra-snmp [Y] Enter

Install zimbra-store [Y] Enter

Install zimbra-apache [Y] Enter

Install zimbra-spell [Y] Enter

Install zimbra-memcached [Y] Enter

Install zimbra-proxy [Y] Enter

The System will be modified. Continue? [N] Y Enter

NOTE: Do not install dnscache because we already installed bind9.

Sometimes it takes for a while to install some packages.

You will receive this error:

DNS ERROR resolving server.domain.com server

Change hostname [Yes] Enter

Please enter the logical hostname for this host [server.domain.com] domain.com

Ports conflicts detected! – Press Enter /Return key to continue Enter

Setup a password for admin account.



This article covers how to create and run a simple shell script in CentOS 8 system. With this, you can easily create and run even complex scripts and automate repetitive tasks. 

If you are using other Linux distributions, you can visit our posts on how to create and run a shell script in Ubuntu , Debian , and Linux Mint .


An SH file is a script programmed for bash, a type of Unix shell (Bourne-Again SHell). It contains instructions written in the Bash language and can be executed by typing text commands within the shell's command-line interface.


To write and execute a script:

1. Open the terminal. Go to the directory where you want to create your script.

2. Create a file with . sh extension.

3. Write the script in the file using an editor.

4. Make the script executable with command chmod +x <fileName>.

5. Run the script using ./<fileName>.



This article covers how you can easily adjust the time, date, and time zone of your system in CentOS 8.

To change the time zone in Linux systems use the sudo timedatectl set-timezone command followed by the long name of the time zone you want to set.


How to Synchronize Time on Installed Linux Operating Systems ?

1. On the Linux machine, log in as root.

2. Run the ntpdate -u <ntpserver> command to update the machine clock. For example, ntpdate -u ntp-time.

3. Open the /etc/ntp. conf file and add the NTP servers used in your environment.

4. Run the service ntpd start command to start the NTP service and implement you configuration changes.


Importance of man command in Linux:

man command in Linux is used to display the user manual of any command that we can run on the terminal. 

It provides a detailed view of the command which includes NAME, SYNOPSIS, DESCRIPTION, OPTIONS, EXIT STATUS, RETURN VALUES, ERRORS, FILES, VERSIONS, EXAMPLES, AUTHORS.



This article covers how you can easily install slack platform on your CentOS 8 Linux system through the command line. 

Using a slack application, team members of an organization can unify all conversations from different sources.


Slack is one of the most popular collaboration platforms in the world that brings all your communication together. 

Conversations in Slack are organized in channels. 

You can create channels for your teams, projects, topics, or any other purpose. 

You can search through everything that's been posted in channels or your messages. 

Slack also allows you to talk with your teammates over audio or video calls and share documents, images, videos, and other files.


To Install Slack on CentOS:

1. Update system

sudo yum -y update

2. Download and Install Slack on CentOS

sudo yum -y install wget

wget https://downloads.slack-edge.com/linux_releases/slack-3.4.0-0.1.fc21.x86_64.rpm

sudo  yum -y install https://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm

sudo yum localinstall slack-3.4.0-0.1.fc21.x86_64.rpm

3. Start and Use Slack

Now that Slack is installed on your CentOS / RHEL 8 desktop, you can launch it through the command line,

$ slack



This article covers how to install the Opera browser using different ways on CentOS 8. We have also shown how you can install packages by using the wget command. Opera browser is amazing on your CentOS 8 system.


To install Opera browser on CentOS:

1. Add Opera YUM repository

Run the following commands to manually add the Opera RPM repository to your RHEL / CentOS 8 system.

$ sudo tee /etc/yum.repos.d/opera.repo <<RPMREPO

[opera]

name=Opera packages

type=rpm-md

baseurl=https://rpm.opera.com/rpm

gpgcheck=1

gpgkey=https://rpm.opera.com/rpmrepo.key

enabled=1

RPMREPO

2. Install Opera Browser on RHEL 8 / CentOS 8

Use yum package manager command to install Opera Browser on RHEL 8 / CentOS 8.

$ sudo yum -y install opera-stable

3. Wait for the installation to complete then launch the browser from the CLI:

$ opera 



This article covers how to setup the NFS server and client on Mint. You will learn how to install the NFS server and client, configure and share NFS export directories, and mount/unmount the NFS shares on the client.

Network File System (NFS), is a distributed file system that allows various remote systems to access a file share. We all know that files should be stored on a central server for security and ease of backup. NFS provides us with a file sharing service that is easily managed and controls client access to resources.


To Install the NFS Client on the Client Systems:

1. Install the NFS-Common Package. As is the norm, begin by updating the system packages and repositories before anything else.

2. Create a NFS Mount Point on Client.

3. Mount NFS Share on Client System.

4. Testing the NFS Share on Client System.


A Network File System (NFS) allows remote hosts to mount file systems over a network and interact with those file systems as though they are mounted locally. This enables system administrators to consolidate resources onto centralized servers on the network.


Benefits of setting up an NFS server:

1. Enables multiple computers to use the same files, so everyone on the network can access the same data.

2. Reduces storage costs by having computers share applications instead of needing local disk space for each user application.



This article covers how to install Wine on CentOS 8. With the use of this package, you can easily use the native Windows applications on CentOS 8. However, you can also remove this package from your CentOS 8 system to conserve the memory whenever you want.


How to Install Wine 4 on CentOS 8:

Install EPEL Repos on CentOS 8

Wine is not included in the default CentOS 8 repositories but however available on EPEL repos. Therefore, run the command below to install EPEL repos:

$ dnf install https://dl.fedoraproject.org/pub/epel/epel-release-latest-8.noarch.rpm


To run Wine on CentOS 8:

Wine command takes the following syntax.

$ wine program [arguments]

To obtain help on Wine usage;

$ wine --help

Consult man pages for Wine for more insight.

$ man wine

Before you can use Wine to run Windows applications, reboot your system to setup the Wine environment.

$ systemctl reboot



This article covers the key Google Chrome extensions which will definitely enhance your browsing experience and will make Google Chrome even more helpful and useful for you. Google Chrome extensions are programs that can be installed into Chrome in order to change the browser's functionality.

Adding to do lists or notes to Chrome. Password management. Making it easier to copy text from a site. Protect your privacy and making web browsing more secure.

Some extensions can be ethically dubious or even malicious, but Chrome features new restrictions on extension developers that should help mitigate that problem.



This article covers how to use the unzip command on the CentOS 8 Linux system.

Also, you will learn various uses of the unzip command through which you can list ZIP archive content and extract files. You can utilize the unzip command according to your needs.


How to Create a ZIP File with the zip Command ?

To create a ZIP file, you need to tell zip the name of the archive file and which files to include in it. 

You don't need to add the ".zip" extension to the archive name, but it does no harm if you do.

To create a file called source_code.zip containing all the C source code files and header files in the current directory, you would use this command:

$ zip source_code *.c *.h


How to Unzip a ZIP File With the unzip Command ?

To extract the files from a ZIP file, use the unzip command, and provide the name of the ZIP file. 

Note that you do need to provide the ".zip" extension.

$ unzip source_code.zip


To Unzip on the Linux command line:

The simplest option that will extract the contents to current directory:

$ unzip backup.zip


To change the target directory for extracted material, use -d option followed by the desired directory:

$ unzip backup.zip -d ./restore-directory


To preview contents of zip file:

$ unzip -l backup.zip


If you don't want to unzip the whole file, then add the specific files to extract at the end:

$ unzip backup.zip file1 subdirectory/file2


The inverse of the above command. Unzip every file EXCEPT the ones specified after the -x modifier:

$ unzip backup.zip -x file1 subdirectory/file2


Unzipping a password protected file:

$ unzip -p mypassword backup.zip



This article covers how to install python2 and python3 on CentOS 8. By default, python2 and python3 are not installed on CentOS 8. To install both, you need to install all python packages separately according to python versions. Also, you can run python2 and python3 environments on your system. 

The 'alternatives --auto python' command is used to set any python version as the default. 


To run Python in Linux:

A widely used way to run Python code is through an interactive session. 

To start a Python interactive session, just open a command-line or terminal and then type in python, or python3 depending on your Python installation, and then hit Enter .


Python comes preinstalled on most Linux distributions, and is available as a package on all others. 

However there are certain features you might want to use that are not available on your distro's package. 

You can easily compile the latest version of Python from source.


Installing Python 3 on Linux:

1. To see which version of Python 3 you have installed, open a command prompt and run

$ python3 --version

2. If you are using Ubuntu 16.10 or newer, then you can easily install Python 3.6 with the following commands:

$ sudo apt-get update

$ sudo apt-get install python3.6

3. If you're using another version of Ubuntu (e.g. the latest LTS release) or you want to use a more current Python, we recommend using the deadsnakes PPA to install Python 3.8:

$ sudo apt-get install software-properties-common

$ sudo add-apt-repository ppa:deadsnakes/ppa

$ sudo apt-get update

$ sudo apt-get install python3.8

4. If you are using other Linux distribution, chances are you already have Python 3 pre-installed as well. If not, use your distribution's package manager. For example on Fedora, you would use dnf:

$ sudo dnf install python3


To see if pip is installed, open a command prompt and run:

$ command -v pip



This article covers how to #install Chrony on Linux Mint 20. Once it will be installed on your system, its daemon will silently work in the background to synchronize your system's clock with the #NTP server. 

However, if you do not want Chrony to perform this job any longer, then you can simply uninstall it as well.

Chrony is a flexible implementation of the Network Time Protocol (NTP). 

It is used to synchronize the system clock from different NTP servers, reference clocks or via manual input.


Chrony comes with two programs:

1. chronyc – command line interface for chrony

2. chronyd – daemon that can be started at boot time


How to Install #Chrony in #Linux :

On some systems, chrony may be installed by default. Still if the package is missing, you can easily install it. 


You can install chrony Using your default package manager tool on your respective Linux distributions using following command:

# yum -y install chrony    [On CentOS/RHEL]

# apt install chrony       [On Debian/Ubuntu]

# dnf -y install chrony    [On Fedora 22+]


To check the status of chronyd use the following command:

# systemctl status chronyd      [On SystemD]

# /etc/init.d/chronyd status    [On Init]


If you want to enable chrony daemon upon boot, you can use the following command:

# systemctl enable chronyd       [On SystemD]

# chkconfig --add chronyd        [On Init]


How to Check Chrony Synchronization in Linux ?

To check if chrony is actually synchronized, we will use it's command line program chronyc, which has the tracking option which will provide relevant information:

# chronyc tracking


To check information about chrony’s sources, you can issue the following command:

# chronyc sources



This article Covers how to install the TermRecord application on CentOS 8. The TermRecord application allows you to better enjoy the recorded #Terminal content. 

TermRecord is a simple, open source, terminal session recorder with easy-to-share self-contained HTML output.

#TermRecord Stores these files as your own notes, email them to collaborators, use them as instructional examples, or whatever you wish.

TermRecord consumes output from the script command with timing information and can create a self-contained HTML file which replays the recorded session without needing to load anything from the web. 

These term sessions can be emailed and viewed on practically any device (including iPads etc.). 

The end user only needs a modern browser.


Features of TermRecord includes:

1. User friendly.

2. Detects the terminal size.

3. Nest sessions.

4. Cross-platform HTML-based output.

5. Stores the output as either JSON, embeddable JavaScript, or a static HTML file.

6. Written in Python.


To install on TermRecord #CentOS:

1. First of all, connect to your server via SSH and make sure that all of your system software is up to date. 

Run the following command to update the package list and upgrade all of your system software to the latest version available:

$ sudo yum update -y

2. Install Pip. 

Add the EPEL Repository:

$sudo yum install epel-release

Install pip:

$ sudo yum install python-pip

Once the installation has completed, you can verify that it was successful by using the following command:

$pip -V

3. Install TermRecord

Install TermRecord using the Python package manager (pip):

$sudo pip install TermRecord


How to use TermRecord on CentOS system ?

Taking a video of the terminal with TermRecord is rather simple, just run the following command (be attentive to capital letters):

TermRecord -o record.html

Note: We specify the output file in which the video will be recorded using the -o option. the .html format is the default format.

For more complex operations check out TermRecord --help



This article covers how to assign and remove multiple IP addresses to and from a single NIC. Based on your preferences, you can either assign the multiple IP addresses temporarily or permanently.

There's no simple command that you can run to determine whether the IP address on a Linux system is assigned by DHCP or static. 

If it changes when the system restarts, it's clearly dynamically assigned, but even a dynamic address has some resistance to change. 

The best way is to look at the configuration file.


To add a static route in Linux:

1. Use the route command with the –p option to add a persistent route: # route -p add default ip-address.

2. Use the route command with the –name option to add a persistent route by specifying a name rather than destination and gateway: # route -p add destination-address gateway-address -name name.


What is ip route command in Linux?

ip route is used to manipulate entries in the kernel routing tables. 

Route types: 

1. unicast - the route entry describes real paths to the destinations covered by the route prefix. 

2. unreachable - these destinations are unreachable. 

Packets are discarded and the ICMP message host unreachable is generated.



This article will cover how to install and remove the PostgreSQL server and create a database in PostgreSQL on CentOS 8. Also you will learn how to add tables in the database by using the SQL query.

PostgreSQL is available from CentOS 8's default AppStream software repository, and there are multiple versions which you can install. 

You can choose between these versions by enabling the appropriate collection of packages and dependencies that align with the version you want to install, with each collection referred to as a module stream.


To List out the available streams for the postgresql module using the dnf command:

$ dnf module list postgresql



This article covers the different methods for the installation of Google Chrome on the CentOS 8 system using the terminal commands and graphical method. 

Once the installation of chrome is complete, now you can feel free to add chrome extensions and favorite themes from the web store of Google Chrome.


To install Google Chrome 78 on a RHEL/CentOS/Fedora Linux:

1. Open the Terminal application. Grab 64bit Google Chrome installer.

2. Type the following command to download 64 bit version of Google Chrome:

wget https://dl.google.com/linux/direct/google-chrome-stable_current_x86_64.rpm

3. Install Google Chrome and its dependencies on a CentOS/RHEL, type:

sudo yum install ./google-chrome-stable_current_*.rpm

4. Start Google Chrome from the CLI:

google-chrome &


To upgrade Google Chrome from an older version:

You can simply update it by typing the following yum command:

$ sudo yum update google-chrome-stable

OR use the following dnf command to update it on a Fedora Linux:

$ sudo dnf update google-chrome-stable


To uninstall Chrome from Ubuntu:

1. Open the Terminal: It should be present on your desktop or taskbar.

2. Type sudo apt-get purge google-chrome-stable and press Enter to uninstall the Chrome browser.

3. Type sudo apt-get autoremove and press Enter to clean up the Package Manager to ensure that there are no lingering files.



This article will guide you on how to install MariaDB on your CentOS 8 system. Now you can create new databases and grant privileges to other database users. Also, you can add users and create new databases for web or desktop applications which will be written in PHP, Python, and so on.

In MariaDB replication is faster whereas in MySQL replication is slower. 

MariaDB is Open Source whereas MySQL uses some proprietary code in its Enterprise Edition. 

MariaDB doesn't support Data Masking and Dynamic column while MySQL supports it. Comparatively MariaDB is faster than MySQL.


To uninstall MariaDB and install mysql:

1. Purge mariadb sudo apt purge mariadb-* Remove all databases ('Yes' answer)

2. Purge mysql sudo apt purge mysql-*

3. Remove folders: sudo rm -r /usr/share/mysql/ sudo rm -r /etc/mysql/ sudo rm -r /lib/systemd/system/mysql.service.

4. Now you can try to install oracle mysql: sudo apt install mysql-server.



This article will guide you on how to configure the NTP server on the #Ubuntu machine and then sync a clock of NTP client machine. Now you can easily set up NTP server and connect multiple client machines with it for time synchronization.

The Network Time Protocol (NTP) is a networking protocol for clock synchronization between computer systems over packet-switched, variable-latency data networks.

NTP is intended to synchronize all participating computers to within a few milliseconds of Coordinated Universal Time (UTC).


How do I start #NTP on Linux?

In order to add command line options to the ntpd service (/etc/init. d/ntpd), one has to edit /etc/sysconfig/ntpd file and add the desired option to the OPTIONS variable, and restart the service via 'service ntpd restart'.


What port does NTP use?

NTP time servers work within the TCP/IP suite and rely on User Datagram Protocol (UDP) port 123. NTP servers are normally dedicated NTP devices that use a single time reference to which they can synchronize a network. 

This time reference is most often a Coordinated Universal Time (UTC) source.


To Sync NTP client with server via command line:

1. Edit the /etc/ntp.

2. Search for the lines beginning server .

3. Replace the server entries with the IP address or hostname of the NTP server or servers with which you want to synchronize.

4. Save the file.

5. Configure the NTP client service to start at run level 3 when the appliance boots.