Add new solr collection resource type

[apache]

Add new solr collection resource type

[HoustonPutman]

Hey Aaron, thanks for reaching out.

So far the operator only really manages solr nodes. Solr has a CollectionsApi to manage collections, so I would imagine that this would just be a wrapper to call that endpoint. What additional features would you want from a Collection CRD?

[AceHack]

The ability to backup and restore collections, the ability to split shards when scaling out, the proper management of ensuring shards are spread across availability zones, just to name a few. The ability to define a schema and migrate a schema over time.

Thanks for the awesome operator.

[HoustonPutman]

I think that's a good point with availability zones and shard splitting, etc. And it would definitely allow for better horizontal scaling (as mentioned in Phase V Auto Pilot, from you other issue).

I'm currently working on the backup and metrics collector CRDs, but I'll loop back around to this after that. Feel free to take a stab and create a PR though!

I do imagine that this CRD would change what the backup CRD would look like, but we can cross that bridge when we get to it.

[AceHack]

One other feature I would like is a CollectionShardDisruptionBudget. It would work just like a PodDisriuptionBudget but when draining a node it would make sure at most only x replicas are down for any collection shard.

[HoustonPutman]

I definitely agree. Would you make a separate issue for that? Cause PodDisruptionBudgets need to be supported as well.

[sepulworld]

I can take a stab at creating the Collection CRD.

[sepulworld]

Initial feature CRD for collections setup and tested here #17

[sepulworld]

We can probably close this now. Initial support in place for collections CRD.