Add support for Namespace as Kind

Add example for using namespaces

plugin/pkg/admission/namespace/autoprovision/admission.go

@@ -0,0 +1,94 @@
+/*
+Copyright 2014 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 autoprovision
+
+import (
+	"io"
+
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/admission"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
+	"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/labels"
+)
+
+func init() {
+	admission.RegisterPlugin("NamespaceAutoProvision", func(client client.Interface, config io.Reader) (admission.Interface, error) {
+		return NewProvision(client), nil
+	})
+}
+
+// provision is an implementation of admission.Interface.
+// It looks at all incoming requests in a namespace context, and if the namespace does not exist, it creates one.
+// It is useful in deployments that do not want to restrict creation of a namespace prior to its usage.
+type provision struct {
+	client client.Interface
+	store  cache.Store
+}
+
+func (p *provision) Admit(a admission.Attributes) (err error) {
+	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
+	}
+	namespace := &api.Namespace{
+		ObjectMeta: api.ObjectMeta{
+			Name:      a.GetNamespace(),
+			Namespace: "",
+		},
+		Status: api.NamespaceStatus{},
+	}
+	_, exists, err := p.store.Get(namespace)
+	if err != nil {
+		return err
+	}
+	if exists {
+		return nil
+	}
+	_, err = p.client.Namespaces().Create(namespace)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func NewProvision(c client.Interface) admission.Interface {
+	store := cache.NewStore(cache.MetaNamespaceKeyFunc)
+	reflector := cache.NewReflector(
+		&cache.ListWatch{
+			Client:        c.(*client.Client),
+			FieldSelector: labels.Everything(),
+			Resource:      "namespaces",
+		},
+		&api.Namespace{},
+		store,
+	)
+	reflector.Run()
+	return &provision{
+		client: c,
+		store:  store,
+	}
+}

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

@@ -0,0 +1,17 @@
+/*
+Copyright 2014 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 autoprovision

plugin/pkg/admission/namespace/exists/admission.go

@@ -0,0 +1,98 @@
+/*
+Copyright 2014 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 exists
+
+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/labels"
+)
+
+func init() {
+	admission.RegisterPlugin("NamespaceExists", func(client client.Interface, config io.Reader) (admission.Interface, error) {
+		return NewExists(client), nil
+	})
+}
+
+// exists is an implementation of admission.Interface.
+// It rejects all incoming requests in a namespace context if the namespace does not exist.
+// It is useful in deployments that want to enforce pre-declaration of a Namespace resource.
+type exists struct {
+	client client.Interface
+	store  cache.Store
+}
+
+func (e *exists) Admit(a admission.Attributes) (err error) {
+	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
+	}
+	namespace := &api.Namespace{
+		ObjectMeta: api.ObjectMeta{
+			Name:      a.GetNamespace(),
+			Namespace: "",
+		},
+		Status: api.NamespaceStatus{},
+	}
+	_, exists, err := e.store.Get(namespace)
+	if err != nil {
+		return err
+	}
+	if exists {
+		return nil
+	}
+	obj := a.GetObject()
+	name := "Unknown"
+	if obj != nil {
+		name, _ = meta.NewAccessor().Name(obj)
+	}
+	return apierrors.NewForbidden(kind, name, fmt.Errorf("Namespace %s does not exist", a.GetNamespace()))
+}
+
+func NewExists(c client.Interface) admission.Interface {
+	store := cache.NewStore(cache.MetaNamespaceKeyFunc)
+	// TODO: look into a list/watch that can work with client.Interface, maybe pass it a ListFunc and a WatchFunc
+	reflector := cache.NewReflector(
+		&cache.ListWatch{
+			Client:        c.(*client.Client),
+			FieldSelector: labels.Everything(),
+			Resource:      "namespaces",
+		},
+		&api.Namespace{},
+		store,
+	)
+	reflector.Run()
+	return &exists{
+		client: c,
+		store:  store,
+	}
+}

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

@@ -0,0 +1,17 @@
+/*
+Copyright 2014 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 exists