Propagate annotations to the StatefulSet (#932)

* Initial commit

* Corrections

- set the type of the new  configuration parameter to be array of
  strings
- propagate the annotations to statefulset at sync

* Enable regular expression matching

* Improvements

-handle rollingUpdate flag
-modularize code
-rename config parameter name

* fix merge error

* Pass annotations to connection pooler deployment

* update code-gen

* Add documentation and update manifests

* add e2e test and introduce option in configmap

* fix service annotations test

* Add unit test

* fix e2e tests

* better key lookup of annotations tests

* add debug message for annotation tests

* Fix typos

* minor fix for looping

* Handle update path and renaming

- handle the update path to update sts and connection pooler deployment.
  This way no need to wait for sync
- rename the parameter to downscaler_annotations
- handle other review comments

* another try to fix python loops

* Avoid unneccessary update events

* Update manifests

* some final polishing

* fix cluster_test after polishing

Co-authored-by: Rafia Sabih <rafia.sabih@zalando.de>
Co-authored-by: Felix Kunde <felix-kunde@gmx.de>

pkg/cluster/sync.go

@@ -3,6 +3,7 @@ package cluster
 import (
 	"context"
 	"fmt"
+	"regexp"
 	"strings"
 
 	acidv1 "github.com/zalando/postgres-operator/pkg/apis/acid.zalan.do/v1"
@@ -358,6 +359,8 @@ func (c *Cluster) syncStatefulSet() error {
 				}
 			}
 		}
+		annotations := c.AnnotationsToPropagate(c.Statefulset.Annotations)
+		c.updateStatefulSetAnnotations(annotations)
 
 		if !podsRollingUpdateRequired && !c.OpConfig.EnableLazySpiloUpgrade {
 			// even if desired and actual statefulsets match
@@ -397,6 +400,30 @@ func (c *Cluster) syncStatefulSet() error {
 	return nil
 }
 
+// AnnotationsToPropagate get the annotations to update if required
+// based on the annotations in postgres CRD
+func (c *Cluster) AnnotationsToPropagate(annotations map[string]string) map[string]string {
+	toPropagateAnnotations := c.OpConfig.DownscalerAnnotations
+	pgCRDAnnotations := c.Postgresql.ObjectMeta.GetAnnotations()
+
+	if toPropagateAnnotations != nil && pgCRDAnnotations != nil {
+		for _, anno := range toPropagateAnnotations {
+			for k, v := range pgCRDAnnotations {
+				matched, err := regexp.MatchString(anno, k)
+				if err != nil {
+					c.logger.Errorf("annotations matching issue: %v", err)
+					return nil
+				}
+				if matched {
+					annotations[k] = v
+				}
+			}
+		}
+	}
+
+	return annotations
+}
+
 // checkAndSetGlobalPostgreSQLConfiguration checks whether cluster-wide API parameters
 // (like max_connections) has changed and if necessary sets it via the Patroni API
 func (c *Cluster) checkAndSetGlobalPostgreSQLConfiguration() error {
@@ -939,6 +966,11 @@ func (c *Cluster) syncConnectionPoolerWorker(oldSpec, newSpec *acidv1.Postgresql
 		}
 	}
 
+	newAnnotations := c.AnnotationsToPropagate(c.ConnectionPooler.Deployment.Annotations)
+	if newAnnotations != nil {
+		c.updateConnectionPoolerAnnotations(newAnnotations)
+	}
+
 	service, err := c.KubeClient.
 		Services(c.Namespace).
 		Get(context.TODO(), c.connectionPoolerName(), metav1.GetOptions{})