Domain switching

[fubarhouse]

This PR basically eliminates the need for hard-coded domains.
Would be handy in the event the domain needed to be changed - it's even configurable.

[tobybellwood]

Can this support multiple domains? IE the default, but also an additional one?

[fubarhouse]

Well, it would be possible to add a second resolver based upon input domains.
Would the idea be that you have an entire stack of pygmy containers for each domain?

Not entirely sure what that would look like, but the idea is that this makes that goal a little easier. It'll remove a blocker for that later down the line, if that is intended.

edit: I remember there is a PR for multiple domain support in haproxy - perhaps that model would be a good starting point. If that was configured then yes, it would require minimal work for pygmy to support.

[fubarhouse]

@tobybellwood see here for example:
amazeeio/docker-haproxy#3

That would be freaking sweet actually and pygmy would do it, but it's not something I have influence over.