Allow pod environment variables to also be sourced from a secret (#946)

* Extend operator configuration to allow for a pod_environment_secret just like pod_environment_configmap

* Add all keys from PodEnvironmentSecrets as ENV vars (using SecretKeyRef to protect the value)

* Apply envVars from pod_environment_configmap and pod_environment_secrets before doing the global settings from the operator config. This allows them to be overriden by the user (via configmap / secret)

* Add ability use a Secret for custom pod envVars (via pod_environment_secret) to admin documentation

* Add pod_environment_secret to Helm chart values.yaml

* Add unit tests for PodEnvironmentConfigMap and PodEnvironmentSecret - highly inspired by @kupson and his very similar PR #481

* Added new parameter pod_environment_secret to operatorconfig CRD and configmap examples

* Add pod_environment_secret to the operationconfiguration CRD

Co-authored-by: Christian Rohmann <christian.rohmann@inovex.de>

charts/postgres-operator/crds/operatorconfigurations.yaml

@@ -149,6 +149,8 @@ spec:
                   type: string
                 pod_environment_configmap:
                   type: string
+                pod_environment_secret:
+                  type: string
                 pod_management_policy:
                   type: string
                   enum:

charts/postgres-operator/values-crd.yaml

@@ -104,6 +104,8 @@ configKubernetes:
   pod_antiaffinity_topology_key: "kubernetes.io/hostname"
   # namespaced name of the ConfigMap with environment variables to populate on every pod
   # pod_environment_configmap: "default/my-custom-config"
+  # name of the Secret (in cluster namespace) with environment variables to populate on every pod
+  # pod_environment_secret: "my-custom-secret"
 
   # specify the pod management policy of stateful sets of Postgres clusters
   pod_management_policy: "ordered_ready"

charts/postgres-operator/values.yaml

@@ -95,6 +95,8 @@ configKubernetes:
   pod_antiaffinity_topology_key: "kubernetes.io/hostname"
   # namespaced name of the ConfigMap with environment variables to populate on every pod
   # pod_environment_configmap: "default/my-custom-config"
+  # name of the Secret (in cluster namespace) with environment variables to populate on every pod
+  # pod_environment_secret: "my-custom-secret"
 
   # specify the pod management policy of stateful sets of Postgres clusters
   pod_management_policy: "ordered_ready"