Merge remote-tracking branch 'origin/master' into v0.4

main.go

@@ -23,6 +23,7 @@ import (
 
 	datadoghqv1alpha1 "github.com/DataDog/datadog-operator/api/v1alpha1"
 	"github.com/DataDog/datadog-operator/controllers"
+	"github.com/DataDog/datadog-operator/pkg/config"
 	"github.com/DataDog/datadog-operator/pkg/controller/debug"
 	"github.com/DataDog/datadog-operator/pkg/secrets"
 	"github.com/DataDog/datadog-operator/pkg/version"
@@ -88,14 +89,14 @@ func main() {
 	// Dispatch CLI flags to each package
 	secrets.SetSecretBackendCommand(secretBackendCommand)
 
-	mgr, err := ctrl.NewManager(ctrl.GetConfigOrDie(), ctrl.Options{
+	mgr, err := ctrl.NewManager(ctrl.GetConfigOrDie(), config.ManagerOptionsWithNamespaces(setupLog, ctrl.Options{
 		Scheme:                 scheme,
 		MetricsBindAddress:     metricsAddr,
 		HealthProbeBindAddress: ":8081",
 		Port:                   9443,
 		LeaderElection:         enableLeaderElection,
 		LeaderElectionID:       "datadog-operator-lock",
-	})
+	}))
 	if err != nil {
 		setupLog.Error(err, "unable to start manager")
 		os.Exit(1)

pkg/config/config.go

@@ -0,0 +1,56 @@
+// Unless explicitly stated otherwise all files in this repository are licensed
+// under the Apache License Version 2.0.
+// This product includes software developed at Datadog (https://www.datadoghq.com/).
+// Copyright 2016-2019 Datadog, Inc.
+
+package config
+
+import (
+	"os"
+	"strings"
+
+	"github.com/go-logr/logr"
+	ctrl "sigs.k8s.io/controller-runtime"
+	"sigs.k8s.io/controller-runtime/pkg/cache"
+)
+
+const (
+	// WatchNamespaceEnvVar is the constant for env variable WATCH_NAMESPACE
+	// which specifies the Namespace to watch.
+	// An empty value means the operator is running with cluster scope.
+	WatchNamespaceEnvVar = "WATCH_NAMESPACE"
+)
+
+// GetWatchNamespaces returns the Namespaces the operator should be watching for changes
+func GetWatchNamespaces() []string {
+	ns, found := os.LookupEnv(WatchNamespaceEnvVar)
+	if !found {
+		return nil
+	}
+
+	// Add support for MultiNamespace set in WATCH_NAMESPACE (e.g ns1,ns2)
+	if strings.Contains(ns, ",") {
+		return strings.Split(ns, ",")
+	}
+
+	return []string{ns}
+}
+
+// ManagerOptionsWithNamespaces returns an updated Options with namespaces information
+func ManagerOptionsWithNamespaces(logger logr.Logger, opt ctrl.Options) ctrl.Options {
+	namespaces := GetWatchNamespaces()
+	switch {
+	case len(namespaces) == 0:
+		logger.Info("Manager will watch and manage resources in all namespaces")
+	case len(namespaces) == 1:
+		logger.Info("Manager will be watching namespace", namespaces[0])
+		opt.Namespace = namespaces[0]
+	case len(namespaces) > 1:
+		// configure cluster-scoped with MultiNamespacedCacheBuilder
+		logger.Info("Manager will be watching multiple namespaces", namespaces)
+		opt.Namespace = ""
+		opt.NewCache = cache.MultiNamespacedCacheBuilder(namespaces)
+	}
+
+	return opt
+}