Add optional namespace filter

cmd/eno-controller/main.go

@@ -14,7 +14,7 @@ import (
 	"github.com/Azure/eno/internal/manager"
 )
 
-// TODO: Expose leader election options
+// TODO: Expose leader election and other manager options
 
 func main() {
 	if err := run(); err != nil {

cmd/eno-reconciler/main.go

@@ -22,17 +22,20 @@ func main() {
 	}
 }
 
-// TODO: Label filters, etc.
-
 func run() error {
 	ctx := ctrl.SetupSignalHandler()
 	var (
 		rediscoverWhenNotFound bool
 		writeBatchInterval     time.Duration
 		discoveryMaxRPS        float32
+
+		mgrOpts = &manager.Options{
+			Rest: ctrl.GetConfigOrDie(),
+		}
 	)
 	flag.BoolVar(&rediscoverWhenNotFound, "rediscover-when-not-found", true, "Invalidate discovery cache when any type is not found in the openapi spec. Set this to false on <= k8s 1.14")
 	flag.DurationVar(&writeBatchInterval, "write-batch-interval", time.Second*5, "The max throughput of composition status updates")
+	mgrOpts.Bind(flag.CommandLine)
 	flag.Parse()
 
 	zl, err := zap.NewProduction()
@@ -41,9 +44,7 @@ func run() error {
 	}
 	logger := zapr.NewLogger(zl)
 
-	mgr, err := manager.New(logger, &manager.Options{
-		Rest: ctrl.GetConfigOrDie(),
-	})
+	mgr, err := manager.New(logger, mgrOpts)
 	if err != nil {
 		return fmt.Errorf("constructing manager: %w", err)
 	}

internal/manager/manager.go

@@ -2,10 +2,13 @@ package manager
 
 import (
 	"context"
+	"flag"
+	"fmt"
 
 	"github.com/go-logr/logr"
 	corev1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/fields"
 	"k8s.io/apimachinery/pkg/labels"
 	"k8s.io/apimachinery/pkg/types"
 	"k8s.io/client-go/rest"
@@ -33,23 +36,48 @@ const (
 
 type Options struct {
 	Rest            *rest.Config
+	Namespace       string
 	HealthProbeAddr string
 	MetricsAddr     string
 }
 
+func (o *Options) Bind(set *flag.FlagSet) {
+	flag.StringVar(&o.Namespace, "namespace", "", "Only reconcile resources in a particular namespace")
+}
+
 func New(logger logr.Logger, opts *Options) (ctrl.Manager, error) {
-	mgr, err := ctrl.NewManager(opts.Rest, manager.Options{
+	mgrOpts := manager.Options{
 		Logger:                 logger,
 		HealthProbeBindAddress: opts.HealthProbeAddr,
 		Metrics: server.Options{
 			BindAddress: opts.MetricsAddr,
 		},
-		Cache: cache.Options{
-			ByObject: map[client.Object]cache.ByObject{
-				&corev1.Pod{}: {Label: labels.SelectorFromSet(labels.Set{ManagerLabelKey: ManagerLabelValue})},
+	}
+
+	podLabelSelector := labels.SelectorFromSet(labels.Set{ManagerLabelKey: ManagerLabelValue})
+	if opts.Namespace == "" {
+		mgrOpts.Cache.ByObject = map[client.Object]cache.ByObject{
+			&corev1.Pod{}: {Label: podLabelSelector},
+		}
+	} else {
+		fieldSelector := fields.ParseSelectorOrDie(fmt.Sprintf("metadata.namespace=%s", opts.Namespace))
+
+		mgrOpts.Cache.ByObject = map[client.Object]cache.ByObject{
+			&corev1.Pod{}: {
+				Label: podLabelSelector,
+				Field: fieldSelector,
 			},
-		},
-	})
+		}
+
+		mgrOpts.Cache.DefaultNamespaces = map[string]cache.Config{
+			opts.Namespace: {
+				LabelSelector: labels.Everything(),
+				FieldSelector: fieldSelector,
+			},
+		}
+	}
+
+	mgr, err := ctrl.NewManager(opts.Rest, mgrOpts)
 	if err != nil {
 		return nil, err
 	}