Fix connection pooler deployment selectors (#1213)

Stick with the existing pooler deployment selector labels to make it compatible with existing deployments.

Make the use of additional labels clear and avoid where not needed.

Deployment Selector and Service Selector now do not use extra labels, pod spec does.

manifests/minimal-fake-pooler-deployment.yaml

@@ -0,0 +1,35 @@
+# will not run but is good enough for tests to fail
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: acid-minimal-cluster-pooler
+  labels:
+    application: db-connection-pooler
+    connection-pooler: acid-minimal-cluster-pooler
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      application: db-connection-pooler
+      connection-pooler: acid-minimal-cluster-pooler
+      cluster-name: acid-minimal-cluster
+  template:
+    metadata:
+      labels:
+        application: db-connection-pooler
+        connection-pooler: acid-minimal-cluster-pooler
+        cluster-name: acid-minimal-cluster
+    spec:
+      serviceAccountName: postgres-operator
+      containers:
+      - name: postgres-operator
+        image: registry.opensource.zalan.do/acid/pgbouncer:master-11
+        imagePullPolicy: IfNotPresent
+        resources:
+          requests:
+            cpu: 100m
+            memory: 250Mi
+          limits:
+            cpu: 500m
+            memory: 500Mi
+        env: []

manifests/postgres-operator.yaml

@@ -2,6 +2,8 @@ apiVersion: apps/v1
 kind: Deployment
 metadata:
   name: postgres-operator
+  labels:
+    application: postgres-operator
 spec:
   replicas: 1
   strategy: