Support referencing DB password in a secret

[holzman]

Allows us to (optionally) pull the external DB password from a secret rather than including it in plaintext in values.yaml

[0xThresh]

Hi @holzman, this is already possible using extraEnvFrom such as:

extraEnvVars:
  - name: DATABASE_PASSWORD
    valueFrom:
      secretKeyRef:
        name: db-secrets
        key: db_password

However, since databaseUrl is a dedicated value, I see the benefit of adding your PR. Please check the Contributing Guide for additional steps you need to take before I can merge, and also please fix your PR trying to remove this unrelated value: https://github.com/open-webui/helm-charts/pull/306/files#diff-f923dfcf40b056769f08b1c67dd4b43fde108d4ddbea3c27e725070d28e9003dL306

[holzman]

Hi @0xThresh,

Good point - alternatively I could just change this PR to explicitly document setting DATABASE_* using extraEnvVars - let me know your preference.

FWIW it was the helm-docs run that purged the fullnameOverride, but I can change it back.