[stable/postgresql] postgres user logins fails after uninstall / install cycle

[jdayllon]

Describe the bug

Example commands (and any other) fails using "postgres" user after cycle like that:

• Install a chart with a name, i.e. : my-postgres : helm install my-postgres stable/postgresql
• Uninstall it : helm uninstall my-postgres
• Reinstall with the same name: helm install my-postgres stable/postgresql

And then if you try any example commands will output:
psql: FATAL: password authentication failed for user "postgres"

Version of Helm and Kubernetes:

Helm v3.0.2
Kubernetes 1.14.8 (Docker for Mac distro)

Which chart:
stable/postgresql-8.1.2

What happened:
After a reinstall i can't login postgres user console outs:
password authentication failed for user

What you expected to happen:
Correct login.

How to reproduce it (as minimally and precisely as possible):
Install, uninstall and reinstall with the same name. If other name is used no problems found.

Anything else we need to know:
N/A

[sameersbn]

@jdayllon the stable/postgresql chart deploys statefulsets for the master and slave pods with persistence enabled by default. When the chart is uninstalled, the statefulset by nature does not remove the PVC's that were attached to the master/slave pods. When you install the chart again with the same name, k8s sees that an PVC's already exist and attached them instead of creating new PVC's. As a result the new deployment will have the same data from the previous installation which means that the passwords will be the same as the previous installation.

If you want a fresh install you either remove the existing pvc's or install the chart with a different name

[jdayllon]

@sameersbn thanks! i'm quite new on helm.