Add hashed configs to pod annotations

pkg/zk/generators.go

@@ -11,6 +11,8 @@
 package zk
 
 import (
+	"crypto/sha256"
+	"encoding/hex"
 	"fmt"
 	"reflect"
 	"strconv"
@@ -96,7 +98,7 @@ func MakeStatefulSet(z *v1beta1.ZookeeperCluster) *appsv1.StatefulSet {
 							"kind": "ZookeeperMember",
 						},
 					),
-					Annotations: z.Spec.Pod.Annotations,
+					Annotations: makeZkPodAnnotations(z),
 				},
 				Spec: makeZkPodSpec(z, extraVolumes),
 			},
@@ -105,6 +107,22 @@ func MakeStatefulSet(z *v1beta1.ZookeeperCluster) *appsv1.StatefulSet {
 	}
 }
 
+// makeZkPodAnnotations returns a map of annotations containing hashed zk config
+// and annotations from CR
+func makeZkPodAnnotations(z *v1beta1.ZookeeperCluster) map[string]string {
+	podAnnotationFromCR := z.Spec.Pod.Annotations
+	hashedZkConfig := sha256.Sum256([]byte(makeZkConfigString(z)))
+
+	annotations := []map[string]string{
+		{
+			"zookeeperConfig": hex.EncodeToString(hashedZkConfig[:]),
+		},
+		podAnnotationFromCR,
+	}
+
+	return mergeAnnotations(annotations...)
+}
+
 func makeZkPodSpec(z *v1beta1.ZookeeperCluster, volumes []v1.Volume) v1.PodSpec {
 	zkContainer := v1.Container{
 		Name:  "zookeeper",
@@ -398,6 +416,18 @@ func mergeLabels(l ...map[string]string) map[string]string {
 	return res
 }
 
+// mergeAnnotations merges annotation maps
+func mergeAnnotations(annotations ...map[string]string) map[string]string {
+	res := make(map[string]string)
+
+	for _, a := range annotations {
+		for k, v := range a {
+			res[k] = v
+		}
+	}
+	return res
+}
+
 // Make a copy of map
 func copyMap(s map[string]string) map[string]string {
 	res := make(map[string]string)