Cluster Chart v0.0.1-alpha

[sxd]

Initial prototype of the cluster chart.

The objective of the chart is to provide a really easy to use interface for cluster recovery and a convention over configuration approach.

It is the better approach in my opinion to simply a wrapper with respect to CNPG, as technically a CNPG cluster is just one resource that needs to be configured correctly.

Based on your feedback in #88 I designed the chart to operate in 3 modes:

1. standalone - That would be your initial CNPG cluster
2. recovery - That's a cluster with a recovery bootstrap section
3. replica - For an off-site replica cluster (TODO)

There are three methods for recovery that you can choose from via recovery.method:

1. backup
2. object_store
3. pg_basebackup (TODO)

The chart by default separates the configuration between backup barmanObjectStore and recovery barmanObjectStore so that no conflicts of configuration arise.

I've implemented an initial-backup that is implemented as a post-install hook so that the cluster can provide PITR from its initialization (as opposed to after its first base or scheduled backup).

The chart includes an interface for specifying multiple ScheduledBackups and a PgBouncer.

I've implemented some base configuration for future out-of-the-box support of PostGIS via the type setting.

Closes: #178