Running desktop apps on Docker containers: X11 forwarding

Table of Contents

• With SSH
• Without SSH
• Complete desktop environment

If you want to do X11 forwarding from your container to your host, you can type these simple commands (these methods work on a local machine, if you are connecting to a remote machine with SSH, it won’t work).

Podman users: you can run these commands with podman, just replace docker with podman.

With SSH

In this method, we are going to install an SSH server on the container. Then, we are going to forward the Thunar File Manager.

docker run -it --rm -e DISPLAY=172.17.0.1:0.0 debian

• For the DISPLAY variable, run ip r and look for the IP of docker0 interface.
• --rm removes the container when you exit from it.

Inside the container:

1. Install SSH server, a text editor and the graphical application

apt update
apt install -y openssh-server thunar nano

2. Edit /etc/ssh/sshd_config to enable X11 forwarding:

nano /etc/ssh/sshd_config

# /etc/ssh/sshd_config
# Modify these lines (uncomment if needed)
X11Forwarding yes
X11UseLocalhost no

3. Run sshd, SSH daemon:

mkdir -p /run/sshd
/usr/sbin/sshd

You can add a user if you don’t want to ssh to the container with the root user:

useradd -m ricardo
passwd ricardo

If you want to use root, first add a password to the root (passwd root), then change this line in /etc/ssh/sshd_config (uncomment if needed):

PermitRootLogin yes

From the host:

1. Connect to the container (using container IP)

ssh -X root@172.17.0.2

2. Run the graphical application:

thunar

Without SSH

docker run -it --rm --net=host -v $HOME/.Xauthority:/root/.Xauthority:ro debian

Inside the container (I’m going to install xterm, a terminal emulator):

export DISPLAY=:0.0
apt update
apt install xterm
xterm

Complete desktop environment

Check How to add a desktop environment via Docker to find some Docker images that include a desktop environment.

If you have any suggestion, feel free to contact me via social media or email.