Create Documentation for using Postgresql, in addition to (and eventually instead of) Cockroachdb, due to future helm chart deprecation

[jessebot]

Cockroachdb's helm chart is being deprecated (date unknown currently), see cockroachdb/helm-charts#230 and the docs here.

It would be nice to see some instructions for Postgresql. I can help with adding a subchart for Bitnami's Postgres helm chart if you'd like. We use it over at the community run Nextcloud helm chart, and it's been pretty smooth sailing so far.

The other issue is that cockroachdb doesn't let you pass in passwords from an existing secret or env var to their init job's provisioning container. See cockroachdb/helm-charts#242 which has not been responded to by anyone from the project in it's year of being open. This means you have to pass in a plain text password if you want to use passwords, which is a non-starter for certain companies and orgs due to security compliance requiring no plain text passwords, even in private repos.

I changed the original title, because it's not yet clear when the helm chart will be deprecated. Cockroachdb also has an Operator which I believe they want you to use instance, but as of now is only tested on GKE and does not have a helm chart at time of writing.

[eliobischof]

Does the PR #111 address what you need?

[jessebot]

yes, after a quick inspection, thank you! I'll open a new issue if anything doesn't work :)