Install VNC on Ubuntu 20.04

Virtual network computing, or VNC, is a graphical desktop sharing system that allows you to control one computer remotely from another. A VNC server transfers keyboard and mouse events, and displays the remote host’s screen via a network connection, which allows you to operate a full desktop environment on your Linode.

This guide explains how to install a graphic desktop environment on your Linode running Ubuntu 20.04 and how to connect to it from your local computer using VNC.

Before You Begin

1. If you have not already done so, create a Linode account and Compute Instance. See our Getting Started with Linode and Creating a Compute Instance guides.

2. Follow our Setting Up and Securing a Compute Instance guide to update your system. You may also wish to set the timezone, configure your hostname, create a limited user account, and harden SSH access.

Install a Desktop and VNC Server on your Linode

1. Ubuntu has several desktop environments available in its repositories. The following command installs the default desktop, Unity, as well as the dependencies that are required for the graphical interface to work properly:

   sudo apt install ubuntu-desktop gnome-panel gnome-settings-daemon metacity nautilus gnome-terminal
   Note

   This will install the full Ubuntu desktop environment, including office and web browsing tools. To install the desktop without these packages, run:

   sudo apt install --no-install-recommends ubuntu-desktop gnome-panel gnome-settings-daemon metacity nautilus gnome-terminal

   During the install process, reply with the defaults to any prompts.

2. Install the VNC server:

   sudo apt install tigervnc-standalone-server

Secure your VNC connection

The VNC server generates a display, or graphical output, identified by a number that is defined when the server starts. If no display number is defined, the server will use the lowest one available. VNC connections take place on port 5900 + display. This guide will use a display number of 1; therefore, you will connect to remote port 5901.

The default VNC connection is unencrypted. In order to secure your passwords and data, you will need to tunnel the traffic through an SSH connection to a local port. You can use the same local port for consistency.

Mac OS X and Linux

1. From your desktop, connect to your Linode with the following command. Be sure to replace user@example.com with your username and your Linode’s hostname or IP address:

   ssh -L 5901:127.0.0.1:5901 user@example.com

2. From your Linode, launch the VNC server to test your connection. You will be prompted to set a password:

   vncserver :1

3. Initiate your connection as per the steps in the Connect to VNC from your Desktop section.

Windows

1. Open PuTTY and navigate to Tunnels under the SSH section in the menu. Add a new forwarded port as shown below, replacing example.com with your Linode’s IP address or hostname:

   

2. Click Add, then return to the ‘Session’ screen. Enter your Linode’s hostname or IP address and a title for your session. Click save to save your settings for future use, and then click open to initiate your SSH tunnel.

3. Launch the VNC server to test your connection. You will be prompted to set a password:

   vncserver :1

4. Initiate your connection as per the steps in the Connect to VNC from your Desktop section.

Connect to VNC from your Desktop

In this section, you will use a VNC client, or viewer, to connect to the remote server. A viewer is the software that draws the graphical display generated by the server and creates the output on your local computer.

Mac OS X and Windows

While there are many options for OS X and Windows, this guide will use RealVNC Viewer.

1. After installing and opening the viewer, connect to the localhost through your VNC client. The format is localhost:#, where # is the display number we used in the Secure your VNC connection section:

2. You will be warned that the connection is unencrypted, but if you have followed the steps above for securing your VNC connection, your session will be securely tunneled to your Linode. To proceed, press Continue.

   

3. You will be prompted to enter the password you specified when first launching the VNC Server. See Secure your VNC Connection if you have not yet started a VNC server on your Linode.

After connecting, you will see a blank gray screen since the desktop processes have not yet been started. In the next section we will configure your Linode to launch a full desktop.

Linux

There are a variety of VNC clients available for Ubuntu desktops. You can find the list here. This guide will use Remmina, which is installed by default.

1. Open Remmina.

   

2. Click the button to Create a new remote desktop profile. Name your profile, specify the VNC protocol, and enter localhost:1 in the server field. The :1 in the server field corresponds to the display number. In the password section fill in the password you specified in Secure your VNC Connection:

   

3. Press Connect.

You’ll see a blank gray screen since the desktop processes have not yet started. In the next section, we will configure your Linode to launch a full desktop.

Configure VNC for a Full Desktop

This section will configure VNC to launch the full Unity desktop when it starts.

1. After you’ve successfully connected, exit the connection. Close the VNC server:

   vncserver -kill :1

2. Create a new file ~/.vnc/xstartup:

   sudo nano ~/.vnc/xstartup

3. Add the following configuration. This starts the desktop dependencies as background processes upon starting the VNC server:

   File: ~/.vnc/xstartup

   1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

   #!/bin/sh # Uncomment the following two lines for normal desktop: # unset SESSION_MANAGER # exec /etc/X11/xinit/xinitrc [ -x /etc/vnc/xstartup ] && exec /etc/vnc/xstartup [ -r $HOME/.Xresources ] && xrdb $HOME/.Xresources xsetroot -solid grey vncconfig -iconic & x-terminal-emulator -geometry 80x24+10+10 -ls -title "$VNCDESKTOP Desktop" & x-window-manager & gnome-panel & gnome-settings-daemon & metacity & nautilus &

4. Save and exit the file.

5. Make the file executable:

   sudo chmod +x ~/.vnc/xstartup

6. Begin another VNC session:

   vncserver :1

7. Connect from your local VNC client using the same steps from the previous section. You should now see the full Ubuntu Desktop:

Starting VNC Server on Boot

This section is optional. Follow these steps to configure the VNC server to start automatically after reboot.

1. Open your crontab. If you’ve never edited it before, you may be prompted to choose a text editor:

   crontab -e

   no crontab for user - using an empty one
   
   Select an editor.  To change later, run 'select-editor'.
     1. /bin/ed
     2. /bin/nano        <---- easiest
     3. /usr/bin/vim.basic
     4. /usr/bin/vim.tiny
   
   Choose 1-4 [2]:

2. Add @reboot /usr/bin/vncserver :1 to the bottom of the file. Your crontab should look like this:

   File: crontab

   1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

   # Edit this file to introduce tasks to be run by cron. # # Each task to run has to be defined through a single line # indicating with different fields when the task will be run # and what command to run for the task # # To define the time you can provide concrete values for # minute (m), hour (h), day of month (dom), month (mon), # and day of week (dow) or use '*' in these fields (for 'any'). # # Notice that tasks will be started based on the cron's system # daemon's notion of time and timezones. # # Output of the crontab jobs (including errors) is sent through # email to the user the crontab file belongs to (unless redirected). # # For example, you can run a backup of all your user accounts # at 5 a.m every week with: # 0 5 * * 1 tar -zcf /var/backups/home.tgz /home/ # # For more information see the manual pages of crontab(5) and cron(8) # # m h dom mon dow command @reboot /usr/bin/vncserver :1

3. Save and exit the file. You can test by rebooting your Linode and connecting to the VNC server. To connect securely to the VNC server see the secure and connect sections.

More Information

You may wish to consult the following resources for additional information on this topic. While these are provided in the hope that they will be useful, please note that we cannot vouch for the accuracy or timeliness of externally hosted materials.

• VNC on Wikipedia
• TigerVNC