We are building our docker image using Dockerfile which copies couple of config files created using Puppet. It would be great if in case any of these config files changes and sends a refresh to the docker::image class, it would rebuild the container image.
Currently this can be (kind of) done by setting ensure to 'latest', but it executes the "docker build" every time, even when there is no change in config files and pollutes the Puppet output in when using --noop.

I think the solution would be to add a refreshonly attribute to the docker::image class, by default set to 'false', and pass this to the Exec["echo 'Update of ${image_arg} complete'"] block which runs in case ensure is set to 'latest'.