You should be able to indicate explicit Service/Port combos.

[Jascen]

I want to use this image multiple times within a single Compose/Stack file. I was prevented from doing that because Stack has a dependency on Services indicating their explicit SERVICE_PORTS. Without being able to indicate explicit Services on a per-HAProxy (this image) basis, the default behavior would map each HAProxy to every Service that it was linked to (Compose) or had Service Ports designated (Swarm).

I've made modifications to support an explicit ServiceName:Port mapping and submitted it in pull request 233.