• Debian

Install and Configure VNC on Debian 9 - Step by Step Process ?

This article covers how to install and configure VNC on Debian Linux System. Also, you will learn how to connect it from Linux, MacOS and Windows local system and manage your Debian 9 server easily using a graphic interface.
VNC (Virtual Network Computing) is a technology for remote desktop sharing. VNC enables the visual desktop display of one computer to be remotely viewed and controlled over a network connection. It is similar to MSTSC on windows. It uses the Remote Frame Buffer protocol (RFB) to remotely control another computer.

To install VNC and XFCE on Debian, run the following commands:

$ apt-get update
$ apt-get install xfce4 xfce4-goodies gnome-icon-theme tightvncserver

To Create a VNC User on Debian:
1. Create a user named vnc by using this command.

$ adduser vnc

$ apt-get install sudo

$ gpasswd -a vnc sudo

$ su - vnc

• CentOS

Install Skype on CentOS 7 System - Step by Step Process ?

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

• Ubuntu

Change Timezone on Ubuntu 18.04 - Step by Step Process ?

This article covers how to change timezone in Ubuntu 18.04. If you have set up your Ubuntu system to fetch Automatic Time Zone, it will sync your system through the internet so that it will have the time zone of your closest location.

Most modern distributions such as Fedora, Debian, Ubuntu, Arch, CentOS v.7.x+, and other Unix-based systems use the timedatectl utility. This command allows you to control and edit time and date settings using the command line.

To display the current time and date information use the command:

$ timedatectl

You can set your Ubuntu system to synchronize to the NIST atomic clock:

$ timedatectl set-ntp yes

If you need to turn off NTP synchronizing to be able to adjust the time and date manually, use:

$ timedatectl set-ntp no

• CentOS

Set Up SSH Keys on CentOS 7 - Step by Step Process ?

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.

• Ubuntu

Change Hostname on Ubuntu 18.04 - How to do it ?

This article covers how to change the hostname on Ubuntu 18.04 system using multiple methods. HostName is also referred to as the computer name of your system. It is used to identify the device in various forms of electronic communication in the computer network. Hostname helps you to access local web pages and other authorized data on your system.

The host name or computer name is usually at system startup in /etc/hostname file.

How to change the computer name on Ubuntu Linux ?

1. Type the following command to edit /etc/hostname using nano or vi text editor:

$ sudo nano /etc/hostname

Delete the old name and setup new name.

2. Next Edit the /etc/hosts file:

$ sudo nano /etc/hosts

Replace any occurrence of the existing computer name with your new one.

3. Reboot the system to changes take effect:

$ sudo reboot

• Ubuntu

Install Node.js and npm on Debian 9 - Step by Step Process ?

This article covers how to install nodejs and npm on your Debian system with different methods. Also, you will learn how to uninstall npm from your Debian system. Node.js is a JavaScript platform for general-purpose programming that allows users to build asynchronous network applications quickly. By leveraging JavaScript on both the front and backend, Node.js can make web application development more consistent and integrated.

To Install the Official Debian Node.js Package:

1. To get Node.js from the default Debian software repository, you can use the apt package manager. First, refresh your local package index:

$ sudo apt update

2. Then install the Node.js package, and npm the Node Package Manager:

$ sudo apt install nodejs npm

3. To verify that the install was successful, run the node command with the -v flag to get the version:

$ node -v

To Remove Node.js:

1. To remove either of these versions, type the following:

$ sudo apt remove nodejs

2. To uninstall a version of Node.js that you have enabled using nvm, first determine whether or not the version you would like to remove is the current active version:

$ nvm current

3. If the version you are targeting is not the current active version, you can run:

$ nvm uninstall node_version

This command will uninstall the selected version of Node.js.

4. If the version you would like to remove is the current active version, you must first deactivate nvm to enable your changes:

$ nvm deactivate