Docker container image with "headless" VNC

This Docker image is installed with the following components:

• Desktop environment Xfce4
• VNC-Server (default VNC port 5901)
• noVNC - HTML5 VNC client (default http port 6901)
• Browsers:
  • Chromium

Build

docker build --rm -f "Dockerfile.ubuntu.xfce.vnc" -t onepanel/vnc:latest .

Usage

• Print out help page:

  docker run onepanel/vnc:latest --help
  

• Run command with mapping to local port 5901 (vnc protocol) and 6901 (vnc web access):

  docker run -d -p 5901:5901 -p 6901:6901 onepanel/vnc:latest
  

• Change the default user and group within a container to your own with adding --user $(id -u):$(id -g):

  docker run -d -p 5901:5901 -p 6901:6901 --user $(id -u):$(id -g) onepanel/vnc:latest
  

• If you want to get into the container use interactive mode -it and bash

  docker run -it -p 5901:5901 -p 6901:6901 onepanel/vnc:latest bash
  

Connect & Control

If the container is started like mentioned above, connect via one of these options:

• connect via VNC viewer localhost:5901, default password: vncpassword
• connect via noVNC HTML5 full client: http://localhost:6901/vnc.html, default password: vncpassword
• connect via noVNC HTML5 lite client: http://localhost:6901/?password=vncpassword

Hints

1. Extend a Image with your own software

Example:

## Custom Dockerfile
FROM onepanel/vnc:latest
ENV REFRESHED_AT 2020-06-01

## Install a gedit
RUN yum install -y gedit \
    && yum clean all

2. Change User of running container

You can change the user id as follows:

2.1. Using root (user id 0)

Add the --user flag to your docker run command:

docker run -it --user 0 -p 6911:6901 onepanel/vnc:latest

2.2. Using user and group id of host system

Add the --user flag to your docker run command:

docker run -it -p 6911:6901 --user $(id -u):$(id -g) onepanel/vnc:latest

3. Override VNC environment variables

The following VNC environment variables can be overwritten at the docker run phase to customize your desktop environment inside the container:

• VNC_COL_DEPTH, default: 24
• VNC_RESOLUTION, default: 1280x1024
• VNC_PW, default: my-pw
• VNC_PASSWORDLESS, default: <not set>

3.1. Example: Override the VNC password

Simply overwrite the value of the environment variable VNC_PW. For example in the docker run command:

docker run -it -p 5901:5901 -p 6901:6901 -e VNC_PW=my-pw onepanel/vnc:latest

3.2. Example: Override the VNC resolution

Simply overwrite the value of the environment variable VNC_RESOLUTION. For example in the docker run command:

docker run -it -p 5901:5901 -p 6901:6901 -e VNC_RESOLUTION=800x600 onepanel/vnc:latest

3.3. Example: Start passwordless

Set VNC_PASSWORDLESS to true to disable the VNC password. It is highly recommended that you put some kind of authorization mechanism before this. For example in the docker run command:

docker run -it -p 5901:5901 -p 6901:6901 -e VNC_PASSWORDLESS=true onepanel/vnc:latest

4. View only VNC

It's possible to prevent unwanted control via VNC. Therefore you can set the environment variable VNC_VIEW_ONLY=true. If set, the startup script will create a random password for the control connection and use the value of VNC_PW for view only connection over the VNC connection.

 docker run -it -p 5901:5901 -p 6901:6901 -e VNC_VIEW_ONLY=true onepanel/vnc:latest

5. Known Issues

5.1. Chromium crashes with high VNC_RESOLUTION

If you open some graphic/work intensive websites in the Docker container (especially with high resolutions, e.g. 1920x1080) Chromium can crash without any specific reason. The problem is that size of /dev/shm too small in the container. You can define this size on startup via the --shm-size option:

docker run --shm-size=256m -it -p 6901:6901 -e VNC_RESOLUTION=1920x1080 onepanel/vnc:latest chromium-browser http://map.norsecorp.com/

Acknowledgments

This repository is a fork of https://github.com/ConSol/docker-headless-vnc-container