Base Image for Desktop Applications on lightweight OpenBox Window Manager - (desktopcontainers/base-alpine) [x86 + arm]

This container is created, to make it easy to use Desktop Applications on Systems that can run Docker Containers. It is based on _/alpine and comes with various way to use your X11 applications:

• VNC (port: 5900, no password)
• HTTP VNC (port: 80, no password)
• HTTPS VNC (port: 443, no password)
• SSH X11 Forwarding (user: app, no password)
  • use it with ssh -X -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no app@127.0.0.1 -p 2222 /container/scripts/app (exported port 22 to 2222 on localhost)
  • use it with ssh -X -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no app@<CONTAINER IP ADRESS> /container/scripts/app
• Local Native X11
  • start container using docker run --rm -ti -v "/tmp/.X11-unix:/tmp/.X11-unix" -v "$HOME/.Xauthority:/home/app/.Xauthority" -e "DISPLAY=$DISPLAY" -h $HOSTNAME --net=host --entrypoint=/container/scripts/app --user=app desktopcontainer/...

Changelogs

• 2020-11-12
  • default VNC_SCREEN_DEPTH to 24
• 2020-11-10
  • added kiosk mode
  • VNC_SCREEN_DEPTH support
• 2020-11-09
  • initial creation on alpine

Environment variables and defaults

General

• SERVER_NAME

  • optional dns name for certificate generation
  • default: localhost

• ENABLE_SUDO

  • set this to enable to allow the user to use sudo
  • default: not set

• ENABLE_KIOSK

  • set this to enable to enable Kiosk mode
    • only run app and make sure it will always restart
    • it is advised to not combine with ENABLE_SUDO - but it's still possible to use with sudo enabled.
  • default: not set
  • perfect for (fullscreen) software like rdesktop, vncviewer, Browser etc.

VNC Settings

• VNC_SCREEN_DEPTH

  • set the screen depth for the xfvb x-server
  • default: 24
  • other possible values:
    • 8
    • 16
    • 24

• VNC_SCREEN_RESOLUTION

  • set this to a specific resolution like '1280x1024' if you want a specific default one
  • default: 1280x1024
  • depth is configured with VNC_SCREEN_DEPTH env
  • other possible values:
    • 640x480
    • 800x600
    • 1024x768
    • 1280x1024
    • 1280x720
    • 1280x800
    • 1280x960
    • 1360x768
    • 1400x1050
    • 1600x1200
    • 1680x1050
    • 1900x1200
    • 1920x1080
    • 1920x1200

Volumes

• /certs/
  • store your certs with the $SERVER_NAME.[key|crt] here.
  • store your ssh host key ssh_host_rsa_key & ssh_host_rsa_key.pub here.
  • if they are missing, they get created

FAQ

• use X11 Forwarding on a new macOS
  • install XQuartz (https://www.xquartz.org/)
  • add XAuthLocation /usr/X11/bin/xauth to your ~/.ssh/config

API

If you wan't to use this container as base for your own containerized Desktop Applications, you can use the following informations to get it done.

It's best to configure everything in a Dockerfile and not at runtime.

Your custom Application

add all your code used for starting your application/s to /container/scripts/app.

Note: There are applications which get in trouble running in multiple instances. Since your Application get's started on container start on the VNC X11 Server, it might collide with the one which is started via SSH. If your application can only run once, make sure the app script kills all other instances before starting a new instance.

Init Points

Add commands to init phase of of entrypoint (only on first run/creation).

sed -i 's/# INIT PHASE/# INIT PHASE\nYOUR_COMMANDS_HERE/g' /container/scripts/entrypoint.sh

Add commands to run phase of of entrypoint (on every run).

sed -i 's/# PRE-RUN PHASE/# PRE-RUN PHASE\nYOUR_COMMANDS_HERE/g' /container/scripts/entrypoint.sh

Openbox Menu

Rename Menu Entry

sed -i 's/Application/NEW_ENTRY_NAME/g' /etc/xdg/openbox/menu.xml

Add Menu Entry

sed -i '0,/<item/ s,,<item label="NEW_ENTRY_NAME"><action name="Execute"><execute>NEW_ENTRY_COMMAND</execute></action></item>\n<item,' /etc/xdg/openbox/menu.xml