Installing a GUI on Ubuntu Server: A Comprehensive Guide

While Ubuntu Server is renowned for its command-line interface, there are scenarios where a graphical user interface (GUI) can significantly enhance usability. Whether you need to run specific applications with graphical interfaces, simplify server management tasks, or prefer a desktop environment for certain operations, adding a GUI to your Ubuntu Server is a viable option. This guide provides a step-by-step approach to installing various levels of GUI on your Ubuntu Server, from minimal setups to full desktop environments.

Understanding Your GUI Options for Ubuntu Server

Before diving into the installation process, it’s crucial to understand the different levels of GUI you can install on Ubuntu Server. Each option caters to different needs and resource considerations:

Minimal GUI: This option provides the bare essentials for a graphical environment. It includes the X Window System (xorg) and a basic window manager like openbox. This is ideal for users who need a GUI for specific applications but want to minimize resource usage.
```
sudo apt install xorg
sudo apt install --no-install-recommends openbox
```
Minimal GUI with Display Manager: Building upon the minimal GUI, this option adds a display manager, such as lightdm. A display manager provides a graphical login screen, making the system more user-friendly, especially after reboots.
```
sudo apt install xorg
sudo apt install --no-install-recommends lightdm-gtk-greeter
sudo apt install --no-install-recommends lightdm
sudo apt install --no-install-recommends openbox
```
Functional Minimal Desktop Environment: For a more complete yet still lightweight experience, you can install a minimal desktop environment like LXDE. LXDE provides essential desktop components, icons, and utilities, making the GUI more functional and visually appealing.
```
sudo apt install xorg
sudo apt install --no-install-recommends lightdm-gtk-greeter
sudo apt install --no-install-recommends lightdm
sudo apt install --no-install-recommends lxde-icon-theme
sudo apt install --no-install-recommends lxde-core
sudo apt install --no-install-recommends lxde-common
sudo apt install --no-install-recommends policykit-1 lxpolkit
sudo apt install --no-install-recommends lxsession-logout
sudo apt install --no-install-recommends gvfs-backends
```
Explanation of LXDE Packages: lxde-icon-theme provides basic icons, lxde-core and lxde-common install core LXDE components, policykit-1 and lxpolkit are necessary for running privileged operations, lxsession-logout ensures the logout menu functions, and gvfs-backends enables features like trash, network browsing, and device support in PCManFM file manager.
Full Lightweight Desktop Environments: If you desire a more feature-rich desktop environment while still maintaining a focus on resource efficiency, you can opt for lightweight desktop environments like Lubuntu Core (LXDE), Xubuntu Core (XFCE), or Ubuntu MATE Core. These options provide a complete desktop experience with a selection of applications and utilities.
```
sudo apt install xorg
```
Then choose one of these options:
```
sudo apt install --no-install-recommends lubuntu-core
```
```
sudo apt install --no-install-recommends xubuntu-core
```
```
sudo apt install --no-install-recommends ubuntu-mate-core
```
Explanation: These *-core metapackages install the base desktop environment (LXDE, XFCE, or MATE) along with essential dependencies like ALSA and LightDM. They include more pre-installed software compared to minimal options but remain lightweight.
Full Desktop Environments (Not Recommended for Most Servers): Installing a full desktop environment like Lubuntu Desktop, Xubuntu Desktop, Ubuntu MATE Desktop, Ubuntu GNOME Desktop, Ubuntu Desktop, or Kubuntu Desktop will provide the complete desktop experience, similar to installing the desktop version of Ubuntu. However, this is generally not recommended for servers as it consumes significant resources and introduces unnecessary software.

Choose one of these options if you understand the resource implications:
```
sudo apt install lubuntu-desktop
```
```
sudo apt install xubuntu-desktop
```
```
sudo apt install ubuntu-mate-desktop
```
```
sudo apt install ubuntu-gnome-desktop
```
```
sudo apt install ubuntu-desktop
```
```
sudo apt install kubuntu-desktop
```
Explanation: These *-desktop metapackages install everything included in the live CD of each Ubuntu flavor. This includes a vast array of applications, media players, and utilities, which are often not needed on a server and can lead to resource wastage and potential security vulnerabilities.

Essential Tips for Ubuntu Server GUI Installation

Tip 1: Using --no-install-recommends with xorg: The --no-install-recommends option is used throughout these commands to install only essential packages and avoid unnecessary recommended packages. Installing xorg first ensures that graphics drivers and core components are installed, which can improve system portability across different hardware.
Tip 2: Network Configuration with Network-Manager: If your chosen GUI option installs network-manager and network-manager-gnome, it’s advisable to use Network Manager for network configuration. To prevent conflicts, remove configurations from /etc/network/interfaces (except for the loopback interface lo).
Tip 3: Remote Desktop with x11vnc: For remote desktop access via x11vnc, options 2 through 6 are suitable. You might need to add -auth guess and -loop options to x11vnc for proper functionality before and after login.
Tip 4: Managing LightDM Autostart: To disable LightDM autostart, use sudo systemctl disable lightdm. Start it manually with sudo systemctl start lightdm. Re-enable with sudo systemctl enable lightdm. If re-enabling fails (shows “static”), reinstall LightDM using sudo apt install --reinstall lightdm.
Tip 5: Desktop Environment Metapackages: Directly installing desktop environment metapackages like lxde, xfce4, mate-desktop-environment, plasma-desktop, unity, or gnome might install more packages than desired, including outdated or less preferred software (e.g., wicd instead of Network Manager in LXDE). Check package details on http://packages.ubuntu.com/ to understand dependencies.
Tip 6: Troubleshooting Greeter Loop: If you encounter a login loop where the greeter returns to the tty prompt, try restarting LightDM with sudo service lightdm restart.

Conclusion: Choosing the Right Ubuntu Server GUI

Adding a GUI to Ubuntu Server offers flexibility and ease of use in certain situations. By understanding the different GUI options and following these steps, you can tailor your server environment to meet your specific needs. For most server tasks, a minimal or functional minimal GUI provides the best balance between usability and resource efficiency. Experiment with the options to find the perfect graphical interface solution for your Ubuntu Server.