Move traefik service setup into it's own docker-compose file

[g7morris]

From Islandora-Devops/isle-dc#6

Comment from @nikathone

"Also it might be a good idea to move the traefik service setup in it's own docker-compose file cause ideally they should only be one traefik service per local host."

We should discuss how to do this post-merge.

[g7morris]

@dannylamb & @nigelgbanks Do we want to optimize towards this on isle-buildkit?

[nigelgbanks]

Might be tricky, I think traefik needs access to the bridge network(s) created by docker-compose to properly redirect the traffic, not sure if it's possible to do this. Might be able to "import" the network and set all of the containers in the docker-compose file to use the "imported" network, but then there wouldn't be any isolation, do the same as using the default network everywhere.

[nigelgbanks]

Looks like we can define the network explicitly, but only one: https://docs.traefik.io/providers/docker/#network

[nigelgbanks]

Found an example of the shared network approach: traefik/traefik#3599 (comment)

[nigelgbanks]

Oh reading though the isle-dc repo I think I misunderstood the use case here. There would be two or more docker-compose.yml files in the same folder so they would run under the same network. Or was the intention for it to work across folders?

[nigelgbanks]

This is covered by Islandora-Devops/isle-dc#83, now users can use a single traefik instance and spin up multiple environments, where can control traefik via INCLUDE_TRAEFIK_SERVICE