This is part of mayfly which demonstrates the concept of testing groups of versions of services in short lived virtual environments.
This is a docker container which uses incrond to reload itself whenever haproxy.cfg changes.
It is updated by haproxy_updater which
mounts the /etc/haproxy folder.
You can build your own version of the container by setting the following environment variable to your docker index username (if you don't it uses mine) and running this bash script:
export DOCKER_ACCOUNT_NAME=<your_name>
sudo -E ./build.sh