Guide to Install VNC Server on AlmaLinux 9

Virtual Network Computing (VNC) is a desktop sharing protocol allowing you to remotely control a computer using VNC client software. VNC is working on GUI (Graphical User Interface) environments, it transmits movements of your mouse and keyboard input over the network using the Remote Frame Buffer (RFB) protocol.

Commonly, VNC is used for technicians to control client desktops or by someone who needs to access their Desktops in the office from their home. VNC can be used securely through a VPN network or SSH tunneling connection.

The following guide will walk you through installing a VNC Server on an AlmaLinux 9 server. You will set up VNC Server with TigerVNC and XFCE on your AlmaLinux server.

Prerequisite

To complete this guide, ensure you have the following:

An AlmaLinux 9 server - This demo will be using AlmaLinux 9 server with hostname alma9 and IP address 192.168.10.20.
A non-root user with administrator privileges.

Installing Desktop Environment

The first step you need to do before installing VNC Server is to decide which Desktop Environment you want to use. On Linux, there are multiple Desktop Environments that you can use, each DE has pros and cons.

If you're running a Linux server within 2/4 of memory, you can use lightweight DEs such as XFCE, Mate, and Cinnamon. But, if you have more memory like 8 GB, then you can use Gnome as your default DE on your server.

The rest of this guide will show you how to set up VNC Server with XFCE as the default DE, which is suitable for any resources that you have. It can run lightweight with small memory on your server.

First, run the dnf command below to add the EPEL repository to your system. When prompted, input y to confirm and press ENTER.

sudo dnf install epel-release

Now, run the following command to install your system's XFCE Desktop and Xorg packages. Input y to confirm the installation, then press ENTER to proceed.

sudo dnf groupinstall "Xfce" "base-x"

Furthermore, if prompted to confirm the GPGP key for the EPEL repository, input y, and press ENTER again.

Once the XFCE and Xorg are installed, run the following command to set up the default startup of your server to use GUI or a graphical environment.

sudo systemctl set-default graphical

If you prefer to use another Desktop Environment, use the following command to install it:

Install Gnome Desktop Environment.

sudo dnf groupinstall "Server with GUI"

Installing KDE Desktop Environment.

sudo dnf groupinstall "KDE Plasma Workspaces"

Installing and Configuring TigerVNC Server

After installing the Desktop Environment, the next step is to install the VNC Server on your AlmaLinux server. In this example, you will be using TigerVNC Server to create your VNC Server.

Below are some step-by-steps that you must do:

Adding New User
Installing TigerVNC Server
Configuring VNC Server with TigerVNC Server

Adding New User

First, you need to create a new user that will be used to run the VNC Server. The following example will show you how to create a new user and set up sudo privileges on your system.

Run the following command to create a new user and password. In this demo, you will create a new user bob.

sudo useradd -m -s /bin/bash bob
sudo passwd bob

Now execute the following command to add user bob to the group wheel. This action allows the user bob to run and execute the sudo command to get the root privileges.

sudo usermod -aG wheel bob

Installing TigerVNC Server

With the new user created, you now will be installing the TigerVNC Server package to your system. The package is available by default on the appstream repository, you can install it via the DNF package manager.

Next, run the dnf command below to install the TigerVNC Server package to your system.

sudo dnf install tigervnc-server

Input y to confirm the installation and press ENTER.

With the new user created and TigerVNC Server installed you're now ready to set up VNC Server via TigerVNC Server.

Configuring VNC Server with TigerVNC Server

In the following section, you will set up VNC Server on your AlmaLinux server with TigerVNC and XFCE Desktop.

Execute the following command to log in as user bob.

su - bob

Run the following command to create a new directory ~/.vnc/ and a new VNC configuration file ~/.vnc/config.

mkdir -p ~/.vnc/
nano ~/.vnc/config

Insert the following configuration. In the session parameter, you can specify the Desktop Environment that will be used. Check the list of files within /usr/share/xsessions directory to get the list of available Desktop Environments on your system.

session=xfce
securitytypes=vncauth,tlsvnc
geometry=1920x1200
localhost
alwaysshared

Save and close the file when you're done.

Next, run the vncpasswd command below to create a new password for your VNC Server.

vncpasswd

Input the new password and repeat. When asked to set up a view-only password, input n to disable it or y to configure it.

Now run the following command to set up the SELinux context for the /home/bob/.vnc directory.

restorecon -RFv /home/bob/.vnc

After that, open the file /etc/tigervnc/vncserver.users using the following nano editor command.

sudo nano /etc/tigervnc/vncserver.users

Add the following line to the file. With this, you will create the VNC Server for display :1 for the user bob.

:1=bob

Save the file and close the editor when finished.

Next, run the systemctl command below to reload the systemd manager.

sudo systemctl daemon-reload

Then start and enable the VNC Server for display :1 using the command below. At the end of the service name is the display number of the VNC Server, and it allows you to create multiple displays on a single server such as vncserver@:2 for VNC Server display :2 and so on.

sudo systemctl start vncserver@:1
sudo systemctl enable vncserver@:1

Lastly, run the following command to verify the VNC Server status for display :1.

sudo systemctl status vncserver@:1

If everything goes well, you should see the VNC Server display :1 status active (running).

Configuring Firewalld

If you followed this guide so far, you have finished the configuration of the VNC Server with TigerVNC and XFCE Desktop. The next step that you must do is to open the VNC Server port on firewalld.

Be sure that the firewalld is activated, or you can run the following command to start it.

sudo systemctl start firewalld

Now run the firewall-cmd commands below to add the vnc-server to the firewalld and reload the firewalld to apply the changes.

sudo firewall-cmd --add-service=vnc-server --permanent
sudo firewall-cmd --reload

Then verify the list of enabled services on firewalld using the command below. The output should indicate that the vnc-server is added to firewalld.

sudo firewall-cmd --list-all

Accessing VNC Server via SSH Tunneling

In this section, you will learn how to connect to VNC Server securely via SSH tunneling. So, before you begin, ensure that the VNC Client software is installed on your local machine. You can use VNC Clients like UltraVNC for Windows or RealVNC if you are using Linux or macOS.

On your local machine, run the ssh command below to create an SSH tunneling to the VNC Server. In this demo, the VNC Server has an IP address of 192.168.10.20 and we'll be using user bob to create the tunneling.

ssh -L 5901:127.0.0.1:5901 -N -f -l bob 192.168.10.20

When the password for user bob when prompted.

Now, open the VNC client application on your local machine and connect to 127.0.0.1 with port 5901. You can access the VNC Server via localhost because you have created a secure SSH tunnel to the VNC Server with port 5901.

When you get the warning about unencrypted connections, click Continue.

Input the VNC Server password when prompted and click OK to confirm.

If you have the correct password for your VNC Server, you should get the default Desktop Environment that you're using. In this demo, the default Desktop Environment is XFCE.

Conclusion

And with that, you've successfully installed VNC Server with TIgerVNC Server and XFCE Desktop on your AlmaLinux 9 machine. You have also learned how to connect to VNC Server securely with SSH Tunneling from your local machine. You can now start using your VNC Server for your main working space.