docker-gen

CI is Jenkins, which uses the Docker plugin for creating slaves on-the-fly. The plugin has it's share of problems, so I don't use it to build the images itself - I do this using a generalized bash script, which also pushes it to our private repo. For automatically updating the load-balancer, check out docker-gen (https://github.com/jwilder/docker-gen). I hacked together setup that detects the latest version and points to this-one when a container comes up or goes down. It assumes a lot of things specific to my setup though (versioning of the containers, env vars, ...)

I ran across a similar thing a few months ago named docker-gen[1]. It listens to the docker event stream in the same way Registrator does, but instead of talking to an external service it regenerates a config file from a template and then optionally runs a command. The canonical example is regenerating a host-wide nginx proxy config when containers start and die, and then restarting nginx. Just goes to show how versatile docker can be by exposing that event stream to arbitrary processes. [1]: https://github.com/jwilder/docker-gen