Add options for rails_cache_store

[dgoetz]

This allows to make use of redis as backend, but still defaults to file.

@timogoebel: Can you have a look as the feature was implemented by you and so you perhaps know best if the parameters make sense in this way?

[dgoetz]

I think the failed tests are unrelated, because it is just Debian failing for "install foreman with prometheus" which runs fine on CentOS.

[timogoebel]

Looks good to me.

[ekohl]

If the cache type is redis, it should install the foreman-redis package.

[dgoetz]

@ekohl I have it included now (also in the tests). Tests are still running.

[laugmanuel]

@dgoetz can I support you in any way on getting this merged? I would love to experiment with this in our release environment.

[dgoetz]

@laugmanuel: No, it needs re-review and comments from @ekohl and @ehelms, so I get input for further adjustments if required.

[dgoetz]

Rebased to resolve merge conflicts, tests failing on debian for statsd seem to be unrelated.

[dgoetz]

I rebased and addressed the comments.

• I removed the additional lines from the rebase.
• An example was added.
• I tested how a hash missing a key is handled and it works fine (according to the puppet docs it is simple handled as undef).

[ehelms]

@dgoetz This will need another rebase

[dgoetz]

Rebased and tests are green except from beaker tests for puppet 5 testing journald, statsd and prometheus, not sure if this is related.

[dgoetz]

Tests are green now, and I hope I have addressed everything.

[ekohl]

Thanks!