Can not run appimages inside rootless docker container

Question

I have installed rootless docker on ubuntu 20.04 [https://docs.docker.com/engine/security/rootless/][1]

I have download vscodium appimage from [https://github.com/VSCodium/vscodium/releases/download/1.66.0/VSCodium-1.66.0-1648720116.glibc2.17-x86_64.AppImage][1]

1. i have shared host directory containing this Appimage with rootless docker container. But it doesn't run. When I manually install(apt-get install) any GUI package(ex. firefox) inside the container it runs successfully.

2. output of the command: docker-compose up vscodium

   Creating vscodium ... done
   Attaching to vscodium
   vscodium | codium: error while loading shared libraries: libnss3.so: cannot open shared object file: No such file or directory
   vscodium exited with code 127

3. content of file docker-compose.yml

   version: "3"
   services:

    vscodium:
    image: python:3.10.4-bullseye
    entrypoint: custom-docker-entrypoint.sh
    container_name: vscodium
    environment:
      - DISPLAY=${DISPLAY}
    volumes:
      - /tmp/.X11-unix:/tmp/.X11-unix:ro
      - $HOME/.Xauthority:$HOME/.Xauthority:ro
      - ./custom-docker-entrypoint.sh:/usr/local/bin/custom-docker-entrypoint.sh
      - ./appImages/VSCodium.AppImage:/ide/VSCodium.AppImage
    network_mode: host
   

4. content of file custom-docker-entrypoint.sh

   #!/bin/sh

   chmod a+x /ide/VSCodium.AppImage

   /ide/VSCodium.AppImage --appimage-extract-and-run

Answer 1

A few notes on running AppImages insude docker:

• AppImages require fuse to run which is usually not available/usable on docker
• Extract the AppImage contents and mount that folder on your docker
• missing libnss3.so, you will have to install this on the host system. If it doesn't work you will have to report it to the AppImage author to for them to include it in the bundle.