Securely provide password to postgres-backend (helm config)

Vault
2

I think you should be able to add your credentials to a Kubernetes secret, and reference those in the Helm chart.

Something like..

spec:
  template:
    spec:
      containers:
        - name: app
          env:
            - name: DB_PASSWORD
              valueFrom:
                secretKeyRef:
                  name: db-creds
                  key: password

There is also this Helm plugin, but I have never used it so please perform due diligence on this plugin and ensure it complies with your companies security policies:

If you maintain multiple clusters, you can also reference secrets from Vault (e.g. you have a management cluster, and separate cluster(s) for different environments.