Merge pull request kubernetes#82248 from rosti/proxyless

kubeadm: Fetching kube-proxy's config map is now optional

Author: k8s-ci-robot

cmd/kubeadm/app/componentconfigs/BUILD

@@ -24,6 +24,7 @@ go_library(
         "//pkg/proxy/apis/config:go_default_library",
         "//pkg/proxy/apis/config/v1alpha1:go_default_library",
         "//pkg/proxy/apis/config/validation:go_default_library",
+        "//staging/src/k8s.io/apimachinery/pkg/api/errors:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/apis/meta/v1:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/runtime:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/runtime/schema:go_default_library",

cmd/kubeadm/app/componentconfigs/config.go

@@ -18,7 +18,9 @@ package componentconfigs
 
 import (
 	"github.com/pkg/errors"
+	"k8s.io/klog"
 
+	apierrors "k8s.io/apimachinery/pkg/api/errors"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/util/version"
@@ -63,6 +65,13 @@ func GetFromKubeProxyConfigMap(client clientset.Interface, version *version.Vers
 	// Read the ConfigMap from the cluster
 	kubeproxyCfg, err := apiclient.GetConfigMapWithRetry(client, metav1.NamespaceSystem, kubeadmconstants.KubeProxyConfigMap)
 	if err != nil {
+		// The Kube-Proxy config map may be non-existent, because the user has decided to manage it by themselves
+		// or to use other proxy solution. It may also be forbidden - if the kube-proxy phase was skipped we have neither
+		// the config map, nor the RBAC rules allowing join access to it.
+		if apierrors.IsNotFound(err) || apierrors.IsForbidden(err) {
+			klog.Warningf("Warning: No kube-proxy config is loaded. Continuing without it: %v", err)
+			return nil, nil
+		}
 		return nil, err
 	}
 

cmd/kubeadm/app/componentconfigs/config_test.go

@@ -47,6 +47,7 @@ func TestGetFromConfigMap(t *testing.T) {
 		component     RegistrationKind
 		configMap     *fakeConfigMap
 		expectedError bool
+		expectedNil   bool
 	}{
 		{
 			name:      "valid kube-proxy",
@@ -59,10 +60,10 @@ func TestGetFromConfigMap(t *testing.T) {
 			},
 		},
 		{
-			name:          "invalid kube-proxy - missing ConfigMap",
-			component:     KubeProxyConfigurationKind,
-			configMap:     nil,
-			expectedError: true,
+			name:        "valid kube-proxy - missing ConfigMap",
+			component:   KubeProxyConfigurationKind,
+			configMap:   nil,
+			expectedNil: true,
 		},
 		{
 			name:      "invalid kube-proxy - missing key",
@@ -123,8 +124,8 @@ func TestGetFromConfigMap(t *testing.T) {
 				return
 			}
 
-			if obj == nil {
-				t.Error("unexpected nil return value")
+			if rt.expectedNil != (obj == nil) {
+				t.Error("unexpected return value")
 			}
 		})
 	}

cmd/kubeadm/app/util/config/cluster.go

@@ -203,6 +203,11 @@ func getComponentConfigs(client clientset.Interface, clusterConfiguration *kubea
 			return err
 		}
 
+		// Some components may not be installed or managed by kubeadm, hence GetFromConfigMap won't return an error or an object
+		if obj == nil {
+			continue
+		}
+
 		if ok := registration.SetToInternalConfig(obj, clusterConfiguration); !ok {
 			return errors.Errorf("couldn't save componentconfig value for kind %q", string(kind))
 		}

cmd/kubeadm/app/util/config/cluster_test.go

@@ -449,7 +449,6 @@ func TestGetComponentConfigs(t *testing.T) {
 					},
 				},
 			},
-			expectedError: true,
 		},
 	}
 
@@ -483,9 +482,6 @@ func TestGetComponentConfigs(t *testing.T) {
 			if cfg.ComponentConfigs.Kubelet == nil {
 				t.Errorf("invalid cfg.ComponentConfigs.Kubelet")
 			}
-			if cfg.ComponentConfigs.KubeProxy == nil {
-				t.Errorf("invalid cfg.ComponentConfigs.KubeProxy")
-			}
 		})
 	}
 }