Added CLUSTER_DNS_NAME env variable to customize headless service according to cluster dns (#181)

Author: deveshk0

pkg/controller/mongodb/replica_set_controller.go

@@ -57,6 +57,7 @@ import (
 
 const (
 	agentImageEnv                = "AGENT_IMAGE"
+	clusterDNSName               = "CLUSTER_DNS_NAME"
 	versionUpgradeHookImageEnv   = "VERSION_UPGRADE_HOOK_IMAGE"
 	agentHealthStatusFilePathEnv = "AGENT_STATUS_FILEPATH"
 	mongodbImageEnv              = "MONGODB_IMAGE"
@@ -423,7 +424,7 @@ func (r ReplicaSetReconciler) ensureAutomationConfig(mdb mdbv1.MongoDB) error {
 }
 
 func buildAutomationConfig(mdb mdbv1.MongoDB, mdbVersionConfig automationconfig.MongoDbVersionConfig, currentAc automationconfig.AutomationConfig, modifications ...automationconfig.Modification) (automationconfig.AutomationConfig, error) {
-	domain := getDomain(mdb.ServiceName(), mdb.Namespace, "")
+	domain := getDomain(mdb.ServiceName(), mdb.Namespace, os.Getenv(clusterDNSName))
 
 	builder := automationconfig.NewBuilder().
 		SetTopology(automationconfig.ReplicaSetTopology).