Merge pull request #3248 from derekwaynecarr/admission_control_hooks

Implement basic admission control framework

plugin/pkg/admission/admit/admission.go

@@ -0,0 +1,42 @@
+/*
+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 admit
+
+import (
+	"io"
+
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/admission"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/client"
+)
+
+func init() {
+	admission.RegisterPlugin("AlwaysAdmit", func(client client.Interface, config io.Reader) (admission.Interface, error) {
+		return NewAlwaysAdmit(), nil
+	})
+}
+
+// alwaysAdmit is an implementation of admission.Interface which always says yes to an admit request.
+// It is useful in tests and when using kubernetes in an open manner.
+type alwaysAdmit struct{}
+
+func (alwaysAdmit) Admit(a admission.Attributes) (err error) {
+	return nil
+}
+
+func NewAlwaysAdmit() admission.Interface {
+	return new(alwaysAdmit)
+}

plugin/pkg/admission/admit/admission_test.go

@@ -0,0 +1,29 @@
+/*
+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 admit
+
+import (
+	"testing"
+)
+
+func TestAdmission(t *testing.T) {
+	handler := NewAlwaysAdmit()
+	err := handler.Admit(nil)
+	if err != nil {
+		t.Errorf("Unexpected error returned from admission handler")
+	}
+}

plugin/pkg/admission/deny/admission.go

@@ -0,0 +1,44 @@
+/*
+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 deny
+
+import (
+	"errors"
+	"io"
+
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/admission"
+	apierrors "github.com/GoogleCloudPlatform/kubernetes/pkg/api/errors"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/client"
+)
+
+func init() {
+	admission.RegisterPlugin("AlwaysDeny", func(client client.Interface, config io.Reader) (admission.Interface, error) {
+		return NewAlwaysDeny(), nil
+	})
+}
+
+// alwaysDeny is an implementation of admission.Interface which always says no to an admission request.
+// It is useful in unit tests to force an operation to be forbidden.
+type alwaysDeny struct{}
+
+func (alwaysDeny) Admit(a admission.Attributes) (err error) {
+	return apierrors.NewForbidden(a.GetKind(), "", errors.New("Admission control is denying all modifications"))
+}
+
+func NewAlwaysDeny() admission.Interface {
+	return new(alwaysDeny)
+}

plugin/pkg/admission/deny/admission_test.go

@@ -0,0 +1,31 @@
+/*
+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 deny
+
+import (
+	"testing"
+
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/admission"
+)
+
+func TestAdmission(t *testing.T) {
+	handler := NewAlwaysDeny()
+	err := handler.Admit(admission.NewAttributesRecord(nil, "foo", "Pod", "ignored"))
+	if err == nil {
+		t.Errorf("Expected error returned from admission handler")
+	}
+}