Add Pulpcore repository class

[ekohl]

This class uses the new yum.theforeman.org repos that are versions per Pulpcore release. This allows easy switching between versions. It also properly sets the GPG key validation.

It does switch acceptance testing from staging repositories to stable repositories. Another implication is that it switches to Pulpcore 3.6 by default. This was chosen since 3.7 is not complete yet.

[ekohl]

@evgeni this probably interests you. I do wonder if we should have some first stage where we test a reduced matrix and then a second stage where we test the rest. For example, 3.7 on Puppet 6 (probably both EL7 and EL8) and then all other variations on it.

[evgeni]

Do you mean interests me to test/stage pulpcore, or puppet-pulpcore?

[ekohl]

Also note that currently it doesn't appear to work yet and it doesn't find the custom fact, hence the draft status.

[ekohl]

Do you mean interests me to test/stage pulpcore, or puppet-pulpcore?

I mostly hope to get some help on the Github actions part but also verification of the RPM packages in the repo.

[ekohl]

Note to self: testing with 3.6 shows

System check identified some issues:
  
  WARNINGS:
  ?: (guardian.W001) Guardian authentication backend is not hooked. You can add this in settings as eg: `AUTHENTICATION_BACKENDS = ('django.contrib.auth.backends.ModelBackend', 'guardian.backends.ObjectPermissionBackend')`.

[ekohl]

Ok, the conclusion is that the 3.7 repo is not installable yet but the mechanism works with 3.4 and 3.6. Caching of gems works well, about 10 seconds on a cache hit is nice.

[ekohl]

Updated. I dropped the multi version testing for later and also pointed the repo to 3.6 instead of 3.7 (which isn't done yet).

[ekohl]

Tests should now also pass.

[ekohl]

Once voxpupuli/voxpupuli-acceptance#13 is merged and released in the gem, you can use BEAKER_FACTER_PULPCORE_VERSION=3.7 when running beaker to test out version 3.7. If it's undefined, it falls back to the class default (3.6).