Merge pull request #28 from nbalacha/watch

controller: operator now watches own namespace

config/manager/manager.yaml

@@ -52,5 +52,10 @@ spec:
           requests:
             cpu: 100m
             memory: 20Mi
+        env:
+        - name: WATCH_NAMESPACE
+          valueFrom:
+            fieldRef:
+              fieldPath: metadata.namespace
       serviceAccountName: controller-manager
       terminationGracePeriodSeconds: 10

main.go

@@ -18,6 +18,7 @@ package main
 
 import (
 	"flag"
+	"fmt"
 	"os"
 
 	// Import all Kubernetes client auth plugins (e.g. Azure, GCP, OIDC, etc.)
@@ -37,8 +38,9 @@ import (
 )
 
 var (
-	scheme   = runtime.NewScheme()
-	setupLog = ctrl.Log.WithName("setup")
+	scheme               = runtime.NewScheme()
+	setupLog             = ctrl.Log.WithName("setup")
+	watchNamespaceEnvVar = "WATCH_NAMESPACE"
 )
 
 func init() {
@@ -65,10 +67,17 @@ func main() {
 
 	ctrl.SetLogger(zap.New(zap.UseFlagOptions(&opts)))
 
+	watchNamespace, err := getWatchNamespace()
+	if err != nil {
+		setupLog.Error(err, "unable to get WatchNamespace, "+
+			"the manager will watch and manage resources in all namespaces")
+	}
+
 	mgr, err := ctrl.NewManager(ctrl.GetConfigOrDie(), ctrl.Options{
 		Scheme:                 scheme,
 		MetricsBindAddress:     metricsAddr,
 		Port:                   9443,
+		Namespace:              watchNamespace,
 		HealthProbeBindAddress: probeAddr,
 		LeaderElection:         enableLeaderElection,
 		LeaderElectionID:       "1136b8a6.topolvm.io",
@@ -102,3 +111,15 @@ func main() {
 		os.Exit(1)
 	}
 }
+
+// getWatchNamespace returns the Namespace the operator should be watching for changes
+func getWatchNamespace() (string, error) {
+	// The env variable WATCH_NAMESPACE which specifies the Namespace to watch.
+	// An empty value means the operator is running with cluster scope.
+
+	ns, found := os.LookupEnv(watchNamespaceEnvVar)
+	if !found {
+		return "", fmt.Errorf("%s not found", watchNamespaceEnvVar)
+	}
+	return ns, nil
+}