Add a readiness probe for the pgAdmin pod

This will ensure that the pod is only ready if pgAdmin is accessible on
port 5050 at the path `/login`. The basic pgadmin test is updated to
ensure that probe exists on the pgadmin pod. The tests already check for
readiness on the pod.

Author: jmckulk

internal/controller/standalone_pgadmin/pod.go

@@ -154,6 +154,26 @@ func pod(
 			},
 		},
 	}
+
+	// Creating a readiness probe that will check that the pgAdmin `/login`
+	// endpoint is reachable at the specified port
+	readinessProbe := &corev1.Probe{
+		ProbeHandler: corev1.ProbeHandler{
+			HTTPGet: &corev1.HTTPGetAction{
+				Port:   *initialize.IntOrStringInt32(pgAdminPort),
+				Path:   "/login",
+				Scheme: corev1.URISchemeHTTP,
+			},
+		},
+	}
+	gunicornData := inConfigMap.Data[gunicornConfigKey]
+	// Check the configmap to see  if we think TLS is enabled
+	// If so, update the readiness check scheme to HTTPS
+	if strings.Contains(gunicornData, "certfile") && strings.Contains(gunicornData, "keyfile") {
+		readinessProbe.ProbeHandler.HTTPGet.Scheme = corev1.URISchemeHTTPS
+	}
+	container.ReadinessProbe = readinessProbe
+
 	startup := corev1.Container{
 		Name:            naming.ContainerPGAdminStartup,
 		Command:         startupCommand(),

internal/controller/standalone_pgadmin/pod_test.go

@@ -111,6 +111,11 @@ containers:
   - containerPort: 5050
     name: pgadmin
     protocol: TCP
+  readinessProbe:
+    httpGet:
+      path: /login
+      port: 5050
+      scheme: HTTP
   resources: {}
   securityContext:
     allowPrivilegeEscalation: false
@@ -291,6 +296,11 @@ containers:
   - containerPort: 5050
     name: pgadmin
     protocol: TCP
+  readinessProbe:
+    httpGet:
+      path: /login
+      port: 5050
+      scheme: HTTP
   resources:
     requests:
       cpu: 100m

testing/kuttl/e2e/standalone-pgadmin/files/00-pgadmin-check.yaml

@@ -26,6 +26,14 @@ metadata:
     postgres-operator.crunchydata.com/data: pgadmin
     postgres-operator.crunchydata.com/role: pgadmin
     postgres-operator.crunchydata.com/pgadmin: pgadmin
+spec:
+  containers:
+  - name: pgadmin
+    readinessProbe:
+      httpGet:
+        path: /login
+        port: 5050
+        scheme: HTTP
 status:
   containerStatuses:
   - name: pgadmin