So this image is just supposed to provide an example of how Docker can be used to set up httpd with vhosts.
If you'd like to build the image yourself you can copy the sources down and do the build from https://github.com/V3ckt0r/docker-httpd-proxy ; # docker build --rm -t <username>/httpd-proxy .
My example used ports 80 and 81, so to run do: # docker run -d -p 80-81:80-81 <username>/httpd
You can check to see its running via: # docker ps
To test: # curl http://localhost