Connection pooler for replica (#1127)

* Enable connection pooler for replica
* Refactor code for connection pooler
  - Move all the relevant code to a separate file
  - Move all the related tests to a separate file
  - Avoid using cluster where not required
  - Simplify the logic in sync and other methods
  - Cleanup of duplicated or unused code
* Fix labels for the replica pods
* Update deleteConnectionPooler to include role
* Adding test cases and other changes
   - Fix unit test and delete secret when required only
   - Make sure we use empty fresh cluster for every test case.
* enhance e2e test
* Disable pooler in complete manifest as this is source for e2e too an creates unnecessary pooler setups.

Co-authored-by: Rafia Sabih <rafia.sabih@zalando.de>
Co-authored-by: Jan Mussler <janm81@gmail.com>

pkg/cluster/connection_pooler_new_test.go

@@ -0,0 +1,45 @@
+package cluster
+
+import (
+	"testing"
+
+	"context"
+
+	appsv1 "k8s.io/api/apps/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+
+	"k8s.io/apimachinery/pkg/labels"
+
+	"k8s.io/client-go/kubernetes/fake"
+)
+
+func TestFakeClient(t *testing.T) {
+	clientSet := fake.NewSimpleClientset()
+	namespace := "default"
+
+	l := labels.Set(map[string]string{
+		"application": "spilo",
+	})
+
+	deployment := &appsv1.Deployment{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "my-deployment1",
+			Namespace: namespace,
+			Labels:    l,
+		},
+	}
+
+	clientSet.AppsV1().Deployments(namespace).Create(context.TODO(), deployment, metav1.CreateOptions{})
+
+	deployment2, _ := clientSet.AppsV1().Deployments(namespace).Get(context.TODO(), "my-deployment1", metav1.GetOptions{})
+
+	if deployment.ObjectMeta.Name != deployment2.ObjectMeta.Name {
+		t.Errorf("Deployments are not equal")
+	}
+
+	deployments, _ := clientSet.AppsV1().Deployments(namespace).List(context.TODO(), metav1.ListOptions{LabelSelector: "application=spilo"})
+
+	if len(deployments.Items) != 1 {
+		t.Errorf("Label search does not work")
+	}
+}