NamespaceLifecycle admission control plugin

cmd/kube-apiserver/app/plugins.go

@@ -34,6 +34,7 @@ import (
 	_ "github.com/GoogleCloudPlatform/kubernetes/plugin/pkg/admission/limitranger"
 	_ "github.com/GoogleCloudPlatform/kubernetes/plugin/pkg/admission/namespace/autoprovision"
 	_ "github.com/GoogleCloudPlatform/kubernetes/plugin/pkg/admission/namespace/exists"
+	_ "github.com/GoogleCloudPlatform/kubernetes/plugin/pkg/admission/namespace/lifecycle"
 	_ "github.com/GoogleCloudPlatform/kubernetes/plugin/pkg/admission/resourcedefaults"
 	_ "github.com/GoogleCloudPlatform/kubernetes/plugin/pkg/admission/resourcequota"
 )

plugin/pkg/admission/namespace/lifecycle/admission.go

@@ -0,0 +1,109 @@
+/*
+Copyright 2015 Google Inc. All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package lifecycle
+
+import (
+	"fmt"
+	"io"
+
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/admission"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
+	apierrors "github.com/GoogleCloudPlatform/kubernetes/pkg/api/errors"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/api/latest"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/api/meta"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/client"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/client/cache"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/fields"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/labels"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/runtime"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/watch"
+)
+
+func init() {
+	admission.RegisterPlugin("NamespaceLifecycle", func(client client.Interface, config io.Reader) (admission.Interface, error) {
+		return NewLifecycle(client), nil
+	})
+}
+
+// lifecycle is an implementation of admission.Interface.
+// It enforces life-cycle constraints around a Namespace depending on its Phase
+type lifecycle struct {
+	client client.Interface
+	store  cache.Store
+}
+
+func (l *lifecycle) Admit(a admission.Attributes) (err error) {
+	if a.GetOperation() != "CREATE" {
+		return nil
+	}
+	defaultVersion, kind, err := latest.RESTMapper.VersionAndKindForResource(a.GetResource())
+	if err != nil {
+		return err
+	}
+	mapping, err := latest.RESTMapper.RESTMapping(kind, defaultVersion)
+	if err != nil {
+		return err
+	}
+	if mapping.Scope.Name() != meta.RESTScopeNameNamespace {
+		return nil
+	}
+	namespaceObj, exists, err := l.store.Get(&api.Namespace{
+		ObjectMeta: api.ObjectMeta{
+			Name:      a.GetNamespace(),
+			Namespace: "",
+		},
+	})
+	if err != nil {
+		return err
+	}
+	if !exists {
+		return nil
+	}
+	namespace := namespaceObj.(*api.Namespace)
+	if namespace.Status.Phase != api.NamespaceTerminating {
+		return nil
+	}
+
+	name := "Unknown"
+	obj := a.GetObject()
+	if obj != nil {
+		name, _ = meta.NewAccessor().Name(obj)
+	}
+	return apierrors.NewForbidden(kind, name, fmt.Errorf("Namespace %s is terminating", a.GetNamespace()))
+}
+
+func NewLifecycle(c client.Interface) admission.Interface {
+	store := cache.NewStore(cache.MetaNamespaceKeyFunc)
+	reflector := cache.NewReflector(
+		&cache.ListWatch{
+			ListFunc: func() (runtime.Object, error) {
+				return c.Namespaces().List(labels.Everything())
+			},
+			WatchFunc: func(resourceVersion string) (watch.Interface, error) {
+				return c.Namespaces().Watch(labels.Everything(), fields.Everything(), resourceVersion)
+			},
+		},
+		&api.Namespace{},
+		store,
+		0,
+	)
+	reflector.Run()
+	return &lifecycle{
+		client: c,
+		store:  store,
+	}
+}

plugin/pkg/admission/namespace/lifecycle/admission_test.go

@@ -0,0 +1,80 @@
+/*
+Copyright 2015 Google Inc. All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package lifecycle
+
+import (
+	"testing"
+
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/admission"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/client"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/client/cache"
+)
+
+// TestAdmission
+func TestAdmission(t *testing.T) {
+	namespaceObj := &api.Namespace{
+		ObjectMeta: api.ObjectMeta{
+			Name:      "test",
+			Namespace: "",
+		},
+		Status: api.NamespaceStatus{
+			Phase: api.NamespaceActive,
+		},
+	}
+	store := cache.NewStore(cache.MetaNamespaceIndexFunc)
+	store.Add(namespaceObj)
+	mockClient := &client.Fake{}
+	handler := &lifecycle{
+		client: mockClient,
+		store:  store,
+	}
+	pod := api.Pod{
+		ObjectMeta: api.ObjectMeta{Name: "123", Namespace: namespaceObj.Namespace},
+		Spec: api.PodSpec{
+			Volumes:    []api.Volume{{Name: "vol"}},
+			Containers: []api.Container{{Name: "ctr", Image: "image"}},
+		},
+	}
+	err := handler.Admit(admission.NewAttributesRecord(&pod, namespaceObj.Namespace, "pods", "CREATE"))
+	if err != nil {
+		t.Errorf("Unexpected error returned from admission handler: %v", err)
+	}
+
+	// change namespace state to terminating
+	namespaceObj.Status.Phase = api.NamespaceTerminating
+	store.Add(namespaceObj)
+
+	// verify create operations in the namespace cause an error
+	err = handler.Admit(admission.NewAttributesRecord(&pod, namespaceObj.Namespace, "pods", "CREATE"))
+	if err == nil {
+		t.Errorf("Expected error rejecting creates in a namespace when it is terminating")
+	}
+
+	// verify update operations in the namespace can proceed
+	err = handler.Admit(admission.NewAttributesRecord(&pod, namespaceObj.Namespace, "pods", "UPDATE"))
+	if err != nil {
+		t.Errorf("Unexpected error returned from admission handler: %v", err)
+	}
+
+	// verify delete operations in the namespace can proceed
+	err = handler.Admit(admission.NewAttributesRecord(nil, namespaceObj.Namespace, "pods", "DELETE"))
+	if err != nil {
+		t.Errorf("Unexpected error returned from admission handler: %v", err)
+	}
+
+}