Merge pull request #880 from sohankunkerkar/federation-namespace

Set kubefed-namespace via the config mechanism for in-cluster deployment

charts/kubefed/charts/controllermanager/templates/deployments.yaml

@@ -20,9 +20,7 @@ spec:
         runAsUser: 1001
       serviceAccountName: kubefed-controller
       containers:
-      - args:
-        - --kubefed-namespace=$(KUBEFED_NAMESPACE)
-        command:
+      - command:
         - /hyperfed/controller-manager
         image: "{{ .Values.repository }}/{{ .Values.image }}:{{ .Values.tag }}"
         imagePullPolicy: "{{ .Values.imagePullPolicy }}"
@@ -38,11 +36,6 @@ spec:
 {{- if .Values.resources }}
 {{ toYaml .Values.resources | indent 12 }}
 {{- end }}
-        env:
-        - name: KUBEFED_NAMESPACE
-          valueFrom:
-            fieldRef:
-              fieldPath: metadata.namespace
       terminationGracePeriodSeconds: 10
 ---
 apiVersion: apps/v1

cmd/controller-manager/app/controller-manager.go

@@ -21,8 +21,10 @@ import (
 	"errors"
 	"flag"
 	"fmt"
+	"io/ioutil"
 	"net/http"
 	"os"
+	"strings"
 
 	"github.com/spf13/cobra"
 	"github.com/spf13/pflag"
@@ -107,6 +109,22 @@ func Run(opts *options.Options, stopChan <-chan struct{}) error {
 		panic(err)
 	}
 
+	runningInCluster := len(masterURL) == 0 && len(kubeconfig) == 0
+	if runningInCluster && len(opts.Config.KubeFedNamespace) == 0 {
+		// For in-cluster deployment set the namespace associated
+		// with the service account token
+		data, err := ioutil.ReadFile("/var/run/secrets/kubernetes.io/serviceaccount/namespace")
+		if err != nil {
+			klog.Fatalf("An error occurred while attempting to discover the KubeFed namespace from the service account: %v", err)
+		}
+		opts.Config.KubeFedNamespace = strings.TrimSpace(string(data))
+	}
+
+	// Validate if a kubefed-namespace is configured
+	if len(opts.Config.KubeFedNamespace) == 0 {
+		klog.Fatalf("The KubeFed namespace must be specified via --kubefed-namespace")
+	}
+
 	setOptionsByKubeFedConfig(opts)
 
 	if err := utilfeature.DefaultFeatureGate.SetFromMap(opts.FeatureGates); err != nil {

cmd/controller-manager/app/options/options.go

@@ -36,7 +36,7 @@ type Options struct {
 
 // AddFlags adds flags to fs and binds them to options.
 func (o *Options) AddFlags(fs *pflag.FlagSet) {
-	fs.StringVar(&o.Config.KubeFedNamespace, "kubefed-namespace", util.DefaultKubeFedSystemNamespace, "The namespace the KubeFed control plane is deployed in.")
+	fs.StringVar(&o.Config.KubeFedNamespace, "kubefed-namespace", "", "The namespace the KubeFed control plane is deployed in.")
 }
 
 func NewOptions() *Options {