Option to configure Prometheus, ClickHouse and Postgres with Secret or ConfigMap

[Jamesits]

Current custom resource implementation only allow setting Prometheus, ClickHouse and Postgres credentials with plain text strings embedded in the CR. Is it possible that we support referencing these credentials from Secret or ConfigMap?

Using the legacy helm chart I can do this:

resource "helm_release" "coroot" {
  name      = "coroot"
  namespace = "coroot"

  repository = "https://coroot.github.io/helm-charts"
  chart      = "coroot"

  atomic          = true
  cleanup_on_fail = true

  set {
    name  = "corootCE.env[0].name"
    value = "PG_CONNECTION_STRING"
  }
  set {
    name  = "corootCE.env[0].valueFrom.secretKeyRef.name"
    value = "postgres"
  }
  set {
    name  = "corootCE.env[0].valueFrom.secretKeyRef.key"
    value = "PG_CONNECTION_STRING"
  }
}