Update Rancher API integration to go-rancher client v2.

[rawmind0]

Description

• Update Rancher API integration to go-rancher client v2, to use stacks not environments.
• Allow the use of labels to autogenerate endpoint, accesskey and secretkey with labels

io.rancher.container.agent.role: environment
io.rancher.container.create_agent: true

• Set default service name and host rule to <service_name>.<stack_name>.<domain> on rancher integration (api and metadata), to match default dns Rancher naming.

[ldez]

@rawmind0 Could you manage the vendor files?
https://github.com/containous/traefik/blob/master/CONTRIBUTING.md#setting-up-glide-and-glide-vc-for-dependency-management

[ldez]

@rawmind0 I will manage the glide part 😄

[rawmind0]

Thanks @ldez ...Tell me if you need anything else... :)

[ldez]

@rawmind0 done!

[rawmind0]

Thanks so much @ldez .. :)

[ldez]

I do not know enough about Rancher to know if the <service_name>. <Stack_name>. <Domain> change is breaking, could you tell me?

[ldez]

In this case, the order is different from <service_name>. <stack_name>, could you explain why?

[rawmind0]

Because one thing is how system establish context hierarchy names for services stack/service set by container label io.rancher.stack_service.name

Another thing is the dns name for the servicesservice.stack.domain to set default traefik Host matcher.. All rancher dns external integrations and internal dns set by default dns entries as service.stack.domain . I think it's useful to make them match by default.

[rawmind0]

This change is just generating default traefik frontend rule to Host: service.stack.domain instead of Host: stack.service.domain , to make it match with default rancher dns entries. You could test that default traefik frontend rule is generated like that.

[mmatur]

LGTM 👏

[nmengin]

LGTM 👏 🐮

[ldez]

LGTM

[ldez]

ping @SantoDE

[SantoDE]

LGTM 👼

I really like that it's a way closer now to match with rancher defaults.

[xaka]

Isn't backward incompatible change? Going from stack.service.domain to service.stack.domain. Curious whether it should be behind a feature flag otherwise going from 1.4 to 1.5 will be painful. Another option is to mention it as a breaking change in changelog. I'd also love to see it as a backport to 1.4 branch to be better prepared. Great stuff!