Make emptyDir volumes work for non-root UIDs

pkg/securitycontext/util.go

@@ -16,7 +16,12 @@ limitations under the License.
 
 package securitycontext
 
-import "github.com/GoogleCloudPlatform/kubernetes/pkg/api"
+import (
+	"fmt"
+	"strings"
+
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
+)
 
 // HasPrivilegedRequest returns the value of SecurityContext.Privileged, taking into account
 // the possibility of nils
@@ -41,3 +46,23 @@ func HasCapabilitiesRequest(container *api.Container) bool {
 	}
 	return len(container.SecurityContext.Capabilities.Add) > 0 || len(container.SecurityContext.Capabilities.Drop) > 0
 }
+
+const expectedSELinuxContextFields = 4
+
+// ParseSELinuxOptions parses a string containing a full SELinux context
+// (user, role, type, and level) into an SELinuxOptions object.  If the
+// context is malformed, an error is returned.
+func ParseSELinuxOptions(context string) (*api.SELinuxOptions, error) {
+	fields := strings.SplitN(context, ":", expectedSELinuxContextFields)
+
+	if len(fields) != expectedSELinuxContextFields {
+		return nil, fmt.Errorf("expected %v fields in selinuxcontext; got %v (context: %v)", expectedSELinuxContextFields, len(fields), context)
+	}
+
+	return &api.SELinuxOptions{
+		User:  fields[0],
+		Role:  fields[1],
+		Type:  fields[2],
+		Level: fields[3],
+	}, nil
+}

pkg/securitycontext/util_test.go

@@ -0,0 +1,85 @@
+/*
+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 securitycontext
+
+import (
+	"testing"
+
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
+)
+
+func TestParseSELinuxOptions(t *testing.T) {
+	cases := []struct {
+		name     string
+		input    string
+		expected *api.SELinuxOptions
+	}{
+		{
+			name:  "simple",
+			input: "user_t:role_t:type_t:s0",
+			expected: &api.SELinuxOptions{
+				User:  "user_t",
+				Role:  "role_t",
+				Type:  "type_t",
+				Level: "s0",
+			},
+		},
+		{
+			name:  "simple + categories",
+			input: "user_t:role_t:type_t:s0:c0",
+			expected: &api.SELinuxOptions{
+				User:  "user_t",
+				Role:  "role_t",
+				Type:  "type_t",
+				Level: "s0:c0",
+			},
+		},
+		{
+			name:  "not enough fields",
+			input: "type_t:s0:c0",
+		},
+	}
+
+	for _, tc := range cases {
+		result, err := ParseSELinuxOptions(tc.input)
+
+		if err != nil {
+			if tc.expected == nil {
+				continue
+			} else {
+				t.Errorf("%v: unexpected error: %v", tc.name, err)
+			}
+		}
+
+		compareContexts(tc.name, tc.expected, result, t)
+	}
+}
+
+func compareContexts(name string, ex, ac *api.SELinuxOptions, t *testing.T) {
+	if e, a := ex.User, ac.User; e != a {
+		t.Errorf("%v: expected user: %v, got: %v", name, e, a)
+	}
+	if e, a := ex.Role, ac.Role; e != a {
+		t.Errorf("%v: expected role: %v, got: %v", name, e, a)
+	}
+	if e, a := ex.Type, ac.Type; e != a {
+		t.Errorf("%v: expected type: %v, got: %v", name, e, a)
+	}
+	if e, a := ex.Level, ac.Level; e != a {
+		t.Errorf("%v: expected level: %v, got: %v", name, e, a)
+	}
+}