security context initial implementation - squash

plugin/pkg/admission/securitycontext/scdeny/admission.go

@@ -0,0 +1,70 @@
+/*
+Copyright 2014 The Kubernetes Authors 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 scdeny
+
+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/client"
+)
+
+func init() {
+	admission.RegisterPlugin("SecurityContextDeny", func(client client.Interface, config io.Reader) (admission.Interface, error) {
+		return NewSecurityContextDeny(client), nil
+	})
+}
+
+// plugin contains the client used by the SecurityContextDeny admission controller
+type plugin struct {
+	client client.Interface
+}
+
+// NewSecurityContextDeny creates a new instance of the SecurityContextDeny admission controller
+func NewSecurityContextDeny(client client.Interface) admission.Interface {
+	return &plugin{client}
+}
+
+// Admit will deny any SecurityContext that defines options that were not previously available in the api.Container
+// struct (Capabilities and Privileged)
+func (p *plugin) Admit(a admission.Attributes) (err error) {
+	if a.GetOperation() == "DELETE" {
+		return nil
+	}
+	if a.GetResource() != string(api.ResourcePods) {
+		return nil
+	}
+
+	pod, ok := a.GetObject().(*api.Pod)
+	if !ok {
+		return apierrors.NewBadRequest("Resource was marked with kind Pod but was unable to be converted")
+	}
+	for _, v := range pod.Spec.Containers {
+		if v.SecurityContext != nil {
+			if v.SecurityContext.SELinuxOptions != nil {
+				return apierrors.NewForbidden(a.GetResource(), pod.Name, fmt.Errorf("SecurityContext.SELinuxOptions is forbidden"))
+			}
+			if v.SecurityContext.RunAsUser != nil {
+				return apierrors.NewForbidden(a.GetResource(), pod.Name, fmt.Errorf("SecurityContext.RunAsUser is forbidden"))
+			}
+		}
+	}
+	return nil
+}

plugin/pkg/admission/securitycontext/scdeny/admission_test.go

@@ -0,0 +1,65 @@
+/*
+Copyright 2014 The Kubernetes Authors 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 scdeny
+
+import (
+	"testing"
+
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/admission"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
+)
+
+// ensures the SecurityContext is denied if it defines anything more than Caps or Privileged
+func TestAdmission(t *testing.T) {
+	handler := NewSecurityContextDeny(nil)
+
+	var runAsUser int64 = 1
+	priv := true
+	successCases := map[string]*api.SecurityContext{
+		"no sc":    nil,
+		"empty sc": {},
+		"valid sc": {Privileged: &priv, Capabilities: &api.Capabilities{}},
+	}
+
+	pod := api.Pod{
+		Spec: api.PodSpec{
+			Containers: []api.Container{
+				{},
+			},
+		},
+	}
+	for k, v := range successCases {
+		pod.Spec.Containers[0].SecurityContext = v
+		err := handler.Admit(admission.NewAttributesRecord(&pod, "Pod", "foo", string(api.ResourcePods), "ignored"))
+		if err != nil {
+			t.Errorf("Unexpected error returned from admission handler for case %s", k)
+		}
+	}
+
+	errorCases := map[string]*api.SecurityContext{
+		"run as user":     {RunAsUser: &runAsUser},
+		"se linux optons": {SELinuxOptions: &api.SELinuxOptions{}},
+		"mixed settings":  {Privileged: &priv, RunAsUser: &runAsUser, SELinuxOptions: &api.SELinuxOptions{}},
+	}
+	for k, v := range errorCases {
+		pod.Spec.Containers[0].SecurityContext = v
+		err := handler.Admit(admission.NewAttributesRecord(&pod, "Pod", "foo", string(api.ResourcePods), "ignored"))
+		if err == nil {
+			t.Errorf("Expected error returned from admission handler for case %s", k)
+		}
+	}
+}