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Tricks with Containers and Small VMs
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:Author: Dimitry Dukhovny


.. contents::


Behold the silly container tricks.


Run GUI Software on Your Headless UNIX Box
==========================================

.. code-block:: bash
	:linenos:
	:caption: Install x11vnc and xvfb

	# For RHEL-like, e.g. Oracle Linux, Centos, or Fedora
	yum -y install x11vnc xvfb
	# For Debian-like, e.g. Ubuntu, Raspbian, or Devuan
	apt-get install x11vnc xvfb
	
	# Create a credential path for the user you want.  Yes, even root (you idiot).
	mkdir ~/.vnc; chmod 700 ~/.vnc
	x11vnc -storepasswd ~/.vnc/passwd  # This will prompt for a password
	
	# Start the VNC server
	x11vnc -forever -usepw -create

Then, connect to to your VM or container using VNC on port 5900.

Start a Docker container with an X GUI and nothing else
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.. code-block:: docker
	:linenos:
	:caption: Dockerfile

	FROM    ubuntu:18.04
	RUN     apt-get update
	RUN     apt-get install -y x11vnc xvfb firefox
	RUN     mkdir ~/.vnc
	RUN     chmod 700 ~/.vnc
	# Notice the password in plain text.  This is bad-ish.
	RUN     x11vnc -storepasswd VNCPASSWORD ~/.vnc/passwd

Fetch a Docker image and start the container

.. code-block:: bash
	:linenos:

	docker build . 2>&1 | tee /tmp/docker-build.out
	# Given no problems...
	docker image tag `grep "Successfully built" /tmp/docker-build.out | awk '{print $NF}'` ubuntu/vnc 
	docker run -p 6900:5900 -e HOME=/root/ ubuntu/vnc x11vnc -forever -usepw -create

Every time you stop this Docker image and restart it, all user settings will flush.  This makes for a great operational browsing window.