We a HaProxy docker image that uses Lua for configuration files, in order to change configuration settings dynamically based on services that have been published within docker cloud with the VIRTUAL_HOST environment variable.
... We currently have Tutum's (Docker Cloud) HaProxy image working with Docker Cloud using service discovery, however it is not using Lua scripting. (It was implemented for our front end web server in order to achieve HA). ... We understand that the later versions of HaProxy do have support for Lua. We are using Docker Cloud's stander HaProxy image for our web site:
We have another reverse proxy server setup with the OpenResty bundle (Nginx + Lua) that is used for our web application.