Need a way to "version" our Docker containers [0.17.3]

[mikeschinkel]

So it seems like we have a Docker container versioning issue. Since we are using the versions of the container service or executable we can't differentiate between their versions and our version.

I am wondering is use DockerHub Web Hooks to call an API of our implementation on a container push where the web hook would update a JSON file with a "last updated" date for the container and commit that update to a Github repo. The box could then pull that JSON file down periodically and compare with the current containers and provide the user a notification that a new version of the container was available.

Or some other approach Thoughts?