Allow to add custom backends in HAProxy

[Cédric Jeanneret deactivated]

Dear Stacker,

In order to get a proper metric flow using prometheus, we need to add a new HAProxy backend on our controllers, exposing an HTTP port with some basic authentication.

In order to do so, I think the best way would be to:
- modify tripleo::haproxy::endpoint in order to allow to add some basic authentication
- modify tripleo::haproxy in order to add a "create_resources(tripleo::haproxy::endpoint, hiera('tripleo::haproxy::endpoints', {})

The first one would require some basic validation and the modification of the call of haproxy::listen (no big deal), and the second one will allow to get, in our custom environment, something like:
ControllerExtraConfig:
  tripleo::haproxy::endpoints:
    custom1:
      <standard parameters>

This would also allow to get a really nice feature, like allowing to move all the code for the creation of the endpoints from tripleo::haproxy to hiera, and use some "merge" feature (hiera_merge I think, or something like that).

I can provide the first step, meaning the two "simple" modification in tripleo::haproxy and tripleo::haproxy::listen - maybe the second step as well in a second time.

Do you agree with that modification and steps? Is that something that might be integrated and, at least for the first step, backported in Pike once it's fully validated?

Thank you for your comments :)

Cheers,

C.

[Alex Schultz (alex-schultz)]

So there's already an effort to do this by refactoring the haproxy to allow for dynamic creation. See https://review.openstack.org/#/q/topic:haproxy-dynamic-endpoints+(status:open+OR+status:merged)

[Cédric Jeanneret deactivated (cjeanneret-c2c-deactivated)]

Oh, thanks for the pointer. I'll check with Juan if he needs any help on that (although it seems on good tracks).