• Ubuntu

Install PHP Composer on Ubuntu 20.04 - Step by Step Process ?

This article covers how to install PHP Composer on Ubuntu 20.04 system. Composer is a popular dependency management tool for PHP, created mainly to facilitate installation and updates for project dependencies. It will check which other packages a specific project depends on and install them for you, using the appropriate versions according to the project requirements. Composer is also commonly used to bootstrap new projects based on popular PHP frameworks, such as Symfony and Laravel.

To Install PHP Composer on Ubuntu:

1. Update your packages:

$ sudo apt-get update

2. Install the curl utility:

$ sudo apt-get install curl

3. Download the installer:

$ sudo curl -s https://getcomposer.org/installer | php

4. Move the composer.phar file:

$ sudo mv composer.phar /usr/local/bin/composer

5. Use the composer command to test the installation. If Composer is installed correctly, the server will respond with a long list of help information and commands:

# composer

• Linux Mint

Enable a Dark Theme in Linux Mint 20 - How to do it ?

This article covers how to enable a dark theme on a Linux Mint 20 system.

How to change themes in Linux Mint ?

1. Search for themes in the Menu and open the Themes applet (Theme Applet provides an easy way of installing and changing themes).

2. At the applet there's a "Add/Remove" button.

3. To install one, all it's needed to do is click on yours preferred one and wait for it to download. After that, the theme will be available at the "Desktop" option on the first page of the applet.

4. Now, double click on one of the installed themes to start using it.

• Ubuntu

Install Apache Cassandra on Ubuntu 20.04 - Step by Step Process ?

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

• Server Management Service

Change Timezone on CentOS 7 Server - Do it Now ?

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

• Server Management Service

Enable SSH on Ubuntu 18.04 System - How to do it ?

This article covers how to install and Enable SSH service on Ubuntu 18.04 system. You can now login remotely to your server using any SSH client from Linux or Windows system. To increase security of SSH connection by Changing default SSH port to custom one on you system. Get more details about SSH server from official SSH site.

When establishing a remote connection between a client and a server, a primary concern is ensuring security. For Linux users, the best practice of accessing and managing your server remotely is through the cryptographic protocol known as Secure Shell (SSH).

How to Enable SSH on Ubuntu ?

1. To install SSH, first update the package repository cache with:

$ sudo apt-get update

2. Now install the OpenSSH software package by entering:

$ sudo apt-get install openssh-server

If prompted, type in your password and press y (yes) to permit the installation.

3. To verify the installation was successful and SSH is running use the command:

$ sudo service ssh status

The confirmation message that you are looking for is: Active: active (running).

• Server Management Service

Change Hostname on CentOS 7 - How to do it ?

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