Update logic for pgbouncer password modification on creation

If the AddPgBouncer call is invoked as the Operator attempts to
add a new pgBouncer and it is determined that a pgBouncer Secret
already exists, do not attempt to update the password within
PostgreSQL.

This also ensures that an existing Secret storing the pgbouncer
user credential is synchronized to be the password represented
for the pgbouncer user in the database itself.

Issue: [ch9457]

Author: jkatz

operator/cluster/pgbouncer.go

@@ -154,15 +154,30 @@ func AddPgbouncer(clientset *kubernetes.Clientset, restclient *rest.RESTClient,
 		}
 	}
 
-	// set the password that will be used for the "pgbouncer" PostgreSQL account
-	pgBouncerPassword, err := generatePassword()
-
-	if err != nil {
-		return err
-	}
-
 	// only attempt to set the password if the cluster is not in standby mode
+	// and the secret does not already exist. If GetPasswordFromSecret returns
+	// no errors, then we can assume that the Secret does not exist
 	if !cluster.Spec.Standby {
+		secretName := util.GeneratePgBouncerSecretName(cluster.Name)
+		pgBouncerPassword, err := util.GetPasswordFromSecret(clientset, cluster.Namespace, secretName)
+
+		if err != nil {
+			// set the password that will be used for the "pgbouncer" PostgreSQL account
+			newPassword, err := generatePassword()
+
+			if err != nil {
+				return err
+			}
+
+			pgBouncerPassword = newPassword
+
+			// create the secret that pgbouncer will include the pgBouncer
+			// credentials
+			if err := createPgbouncerSecret(clientset, cluster, pgBouncerPassword); err != nil {
+				return err
+			}
+		}
+
 		// attempt to update the password in PostgreSQL, as this is how pgBouncer
 		// will properly interface with PostgreSQL
 		if err := setPostgreSQLPassword(clientset, restconfig, pod, cluster.Spec.Port, pgBouncerPassword); err != nil {
@@ -218,7 +233,8 @@ func DeletePgbouncer(clientset *kubernetes.Clientset, restclient *rest.RESTClien
 	}
 
 	// next, delete the various Kubernetes objects associated with the pgbouncer
-	// these include the Service, Deployment, and the pgBouncer secret
+	// these include the Service, Deployment, Secret and ConfigMap associated with
+	// pgbouncer
 	// If these fail, we'll just pass through
 	//
 	// First, delete the Service and Deployment, which share the same naem