Make env var overwrite configmap setting for watching namespaces

cmd/main.go

@@ -27,14 +27,9 @@ func init() {
 	flag.BoolVar(&config.NoTeamsAPI, "noteamsapi", false, "Disable all access to the teams API")
 	flag.Parse()
 
-	config.Namespace = os.Getenv("WATCH_NAMESPACE")
-	if config.Namespace == "" {
-		config.Namespace = "default"
-	}
-
-	configMap := os.Getenv("CONFIG_MAP_NAME")
-	if configMap != "" {
-		err := config.ConfigMapName.Decode(configMap)
+	configMapRawName := os.Getenv("CONFIG_MAP_NAME")
+	if configMapRawName != "" {
+		err := config.ConfigMapName.Decode(configMapRawName)
 		if err != nil {
 			log.Fatalf("incorrect config map name")
 		}

manifests/configmap.yaml

@@ -4,6 +4,7 @@ metadata:
   name: postgres-operator
 data:
   # assumes the ns exists before the operator starts
+  # the env var with the same name may overwrite it in the operator pod
   # watched_namespace: development
   service_account_name: operator
   cluster_labels: application:spilo

manifests/postgres-operator.yaml

@@ -15,9 +15,10 @@ spec:
         image: registry.opensource.zalan.do/acid/postgres-operator:c17aabb
         imagePullPolicy: IfNotPresent
         env:
-        - name: WATCH_NAMESPACE
-          valueFrom:
-            fieldRef:
-              fieldPath: metadata.namespace
+        # uncomment to overwrite a similar setting from operator configmap
+        # - name: WATCHED_NAMESPACE
+        #  valueFrom:
+        #    fieldRef:
+        #      fieldPath: metadata.namespace
         - name: CONFIG_MAP_NAME
           value: "postgres-operator"

pkg/controller/controller.go

@@ -97,9 +97,21 @@ func (c *Controller) initOperatorConfig() {
 		c.logger.Infoln("no ConfigMap specified. Loading default values")
 	}
 
-	if configMapData["watched_namespace"] == "" { // Namespace in ConfigMap has priority over env var
-		configMapData["watched_namespace"] = c.config.Namespace
+	// env var takes priority over the same param from the operator ConfigMap
+	watchedNamespace := os.Getenv("WATCHED_NAMESPACE")
+	if watchedNamespace != "" {
+		c.logger.Infof("Watch the %q namespace specified in the env variable WATCHED_NAMESPACE\n", watchedNamespace)
+		configMapData["watched_namespace"] = watchedNamespace
 	}
+
+	if configMapData["watched_namespace"] == "" {
+		c.logger.Infoln("No namespace to watch specified. Fall back to watching the 'default' namespace.")
+		configMapData["watched_namespace"] = v1.NamespaceDefault
+	}
+
+	// display the actual namespace in case someone checks the value manually
+	os.Setenv("WATCHED_NAMESPACE", configMapData["watched_namespace"])
+
 	if c.config.NoDatabaseAccess {
 		configMapData["enable_database_access"] = "false"
 	}