Expose single annotation/label via downward API

hack/import-restrictions.yaml

@@ -4,6 +4,7 @@
   - k8s.io/apiserver/pkg/util/feature
   - k8s.io/kubernetes/pkg/apis/core
   - k8s.io/kubernetes/pkg/features
+  - k8s.io/kubernetes/pkg/fieldpath
   - k8s.io/kubernetes/pkg/util
   - k8s.io/api/core/v1
 

pkg/apis/core/BUILD

@@ -51,6 +51,7 @@ filegroup(
         "//pkg/apis/core/fuzzer:all-srcs",
         "//pkg/apis/core/helper:all-srcs",
         "//pkg/apis/core/install:all-srcs",
+        "//pkg/apis/core/pods:all-srcs",
         "//pkg/apis/core/v1:all-srcs",
         "//pkg/apis/core/validation:all-srcs",
     ],

pkg/apis/core/pods/BUILD

@@ -0,0 +1,30 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library", "go_test")
+
+go_library(
+    name = "go_default_library",
+    srcs = ["helpers.go"],
+    importpath = "k8s.io/kubernetes/pkg/apis/core/pods",
+    visibility = ["//visibility:public"],
+    deps = ["//pkg/fieldpath:go_default_library"],
+)
+
+go_test(
+    name = "go_default_test",
+    srcs = ["helpers_test.go"],
+    importpath = "k8s.io/kubernetes/pkg/apis/core/pods",
+    library = ":go_default_library",
+)
+
+filegroup(
+    name = "package-srcs",
+    srcs = glob(["**"]),
+    tags = ["automanaged"],
+    visibility = ["//visibility:private"],
+)
+
+filegroup(
+    name = "all-srcs",
+    srcs = [":package-srcs"],
+    tags = ["automanaged"],
+    visibility = ["//visibility:public"],
+)

pkg/apis/core/pods/helpers.go

@@ -0,0 +1,63 @@
+/*
+Copyright 2017 The Kubernetes Authors.
+
+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 pods
+
+import (
+	"fmt"
+
+	"k8s.io/kubernetes/pkg/fieldpath"
+)
+
+// ConvertDownwardAPIFieldLabel converts the specified downward API field label
+// and its value in the pod of the specified version to the internal version,
+// and returns the converted label and value. This function returns an error if
+// the conversion fails.
+func ConvertDownwardAPIFieldLabel(version, label, value string) (string, string, error) {
+	if version != "v1" {
+		return "", "", fmt.Errorf("unsupported pod version: %s", version)
+	}
+
+	if path, _, ok := fieldpath.SplitMaybeSubscriptedPath(label); ok {
+		switch path {
+		case "metadata.annotations", "metadata.labels":
+			return label, value, nil
+		default:
+			return "", "", fmt.Errorf("field label does not support subscript: %s", label)
+		}
+	}
+
+	switch label {
+	case "metadata.annotations",
+		"metadata.labels",
+		"metadata.name",
+		"metadata.namespace",
+		"metadata.uid",
+		"spec.nodeName",
+		"spec.restartPolicy",
+		"spec.serviceAccountName",
+		"spec.schedulerName",
+		"status.phase",
+		"status.hostIP",
+		"status.podIP":
+		return label, value, nil
+	// This is for backwards compatibility with old v1 clients which send spec.host
+	case "spec.host":
+		return "spec.nodeName", value, nil
+	default:
+		return "", "", fmt.Errorf("field label not supported: %s", label)
+	}
+}

pkg/apis/core/pods/helpers_test.go

@@ -0,0 +1,87 @@
+/*
+Copyright 2017 The Kubernetes Authors.
+
+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 pods
+
+import (
+	"testing"
+)
+
+func TestConvertDownwardAPIFieldLabel(t *testing.T) {
+	testCases := []struct {
+		version       string
+		label         string
+		value         string
+		expectedErr   bool
+		expectedLabel string
+		expectedValue string
+	}{
+		{
+			version:     "v2",
+			label:       "metadata.name",
+			value:       "test-pod",
+			expectedErr: true,
+		},
+		{
+			version:     "v1",
+			label:       "invalid-label",
+			value:       "value",
+			expectedErr: true,
+		},
+		{
+			version:       "v1",
+			label:         "metadata.name",
+			value:         "test-pod",
+			expectedLabel: "metadata.name",
+			expectedValue: "test-pod",
+		},
+		{
+			version:       "v1",
+			label:         "metadata.annotations",
+			value:         "myValue",
+			expectedLabel: "metadata.annotations",
+			expectedValue: "myValue",
+		},
+		{
+			version:       "v1",
+			label:         "metadata.annotations['myKey']",
+			value:         "myValue",
+			expectedLabel: "metadata.annotations['myKey']",
+			expectedValue: "myValue",
+		},
+		{
+			version:       "v1",
+			label:         "spec.host",
+			value:         "127.0.0.1",
+			expectedLabel: "spec.nodeName",
+			expectedValue: "127.0.0.1",
+		},
+	}
+	for _, tc := range testCases {
+		label, value, err := ConvertDownwardAPIFieldLabel(tc.version, tc.label, tc.value)
+		if err != nil {
+			if tc.expectedErr {
+				continue
+			}
+			t.Errorf("ConvertDownwardAPIFieldLabel(%s, %s, %s) failed: %s",
+				tc.version, tc.label, tc.value, err)
+		}
+		if tc.expectedLabel != label || tc.expectedValue != value {
+			t.Errorf("ConvertDownwardAPIFieldLabel(%s, %s, %s) = (%s, %s, nil), expected (%s, %s, nil)",
+				tc.version, tc.label, tc.value, label, value, tc.expectedLabel, tc.expectedValue)
+		}
+	}
+}

pkg/apis/core/v1/conversion.go

@@ -157,20 +157,15 @@ func addConversionFuncs(scheme *runtime.Scheme) error {
 	err = scheme.AddFieldLabelConversionFunc("v1", "Pod",
 		func(label, value string) (string, string, error) {
 			switch label {
-			case "metadata.annotations",
-				"metadata.labels",
-				"metadata.name",
+			case "metadata.name",
 				"metadata.namespace",
-				"metadata.uid",
 				"spec.nodeName",
 				"spec.restartPolicy",
-				"spec.serviceAccountName",
 				"spec.schedulerName",
 				"status.phase",
-				"status.hostIP",
 				"status.podIP":
 				return label, value, nil
-				// This is for backwards compatibility with old v1 clients which send spec.host
+			// This is for backwards compatibility with old v1 clients which send spec.host
 			case "spec.host":
 				return "spec.nodeName", value, nil
 			default:

pkg/apis/core/validation/BUILD

@@ -18,10 +18,12 @@ go_library(
         "//pkg/api/service:go_default_library",
         "//pkg/apis/core:go_default_library",
         "//pkg/apis/core/helper:go_default_library",
+        "//pkg/apis/core/pods:go_default_library",
         "//pkg/apis/core/v1:go_default_library",
         "//pkg/apis/core/v1/helper:go_default_library",
         "//pkg/capabilities:go_default_library",
         "//pkg/features:go_default_library",
+        "//pkg/fieldpath:go_default_library",
         "//pkg/security/apparmor:go_default_library",
         "//vendor/github.com/golang/glog:go_default_library",
         "//vendor/k8s.io/api/core/v1:go_default_library",

pkg/apis/core/validation/validation.go

@@ -42,14 +42,15 @@ import (
 	"k8s.io/apimachinery/pkg/util/validation"
 	"k8s.io/apimachinery/pkg/util/validation/field"
 	utilfeature "k8s.io/apiserver/pkg/util/feature"
-	"k8s.io/kubernetes/pkg/api/legacyscheme"
 	apiservice "k8s.io/kubernetes/pkg/api/service"
 	"k8s.io/kubernetes/pkg/apis/core"
 	"k8s.io/kubernetes/pkg/apis/core/helper"
+	podshelper "k8s.io/kubernetes/pkg/apis/core/pods"
 	corev1 "k8s.io/kubernetes/pkg/apis/core/v1"
 	v1helper "k8s.io/kubernetes/pkg/apis/core/v1/helper"
 	"k8s.io/kubernetes/pkg/capabilities"
 	"k8s.io/kubernetes/pkg/features"
+	"k8s.io/kubernetes/pkg/fieldpath"
 	"k8s.io/kubernetes/pkg/security/apparmor"
 )
 
@@ -960,7 +961,7 @@ func validateFlockerVolumeSource(flocker *core.FlockerVolumeSource, fldPath *fie
 	return allErrs
 }
 
-var validDownwardAPIFieldPathExpressions = sets.NewString(
+var validVolumeDownwardAPIFieldPathExpressions = sets.NewString(
 	"metadata.name",
 	"metadata.namespace",
 	"metadata.labels",
@@ -975,7 +976,7 @@ func validateDownwardAPIVolumeFile(file *core.DownwardAPIVolumeFile, fldPath *fi
 	}
 	allErrs = append(allErrs, validateLocalNonReservedPath(file.Path, fldPath.Child("path"))...)
 	if file.FieldRef != nil {
-		allErrs = append(allErrs, validateObjectFieldSelector(file.FieldRef, &validDownwardAPIFieldPathExpressions, fldPath.Child("fieldRef"))...)
+		allErrs = append(allErrs, validateObjectFieldSelector(file.FieldRef, &validVolumeDownwardAPIFieldPathExpressions, fldPath.Child("fieldRef"))...)
 		if file.ResourceFieldRef != nil {
 			allErrs = append(allErrs, field.Invalid(fldPath, "resource", "fieldRef and resourceFieldRef can not be specified simultaneously"))
 		}
@@ -1898,7 +1899,14 @@ func ValidateEnv(vars []core.EnvVar, fldPath *field.Path) field.ErrorList {
 	return allErrs
 }
 
-var validFieldPathExpressionsEnv = sets.NewString("metadata.name", "metadata.namespace", "metadata.uid", "spec.nodeName", "spec.serviceAccountName", "status.hostIP", "status.podIP")
+var validEnvDownwardAPIFieldPathExpressions = sets.NewString(
+	"metadata.name",
+	"metadata.namespace",
+	"metadata.uid",
+	"spec.nodeName",
+	"spec.serviceAccountName",
+	"status.hostIP",
+	"status.podIP")
 var validContainerResourceFieldPathExpressions = sets.NewString("limits.cpu", "limits.memory", "limits.ephemeral-storage", "requests.cpu", "requests.memory", "requests.ephemeral-storage")
 
 func validateEnvVarValueFrom(ev core.EnvVar, fldPath *field.Path) field.ErrorList {
@@ -1912,7 +1920,7 @@ func validateEnvVarValueFrom(ev core.EnvVar, fldPath *field.Path) field.ErrorLis
 
 	if ev.ValueFrom.FieldRef != nil {
 		numSources++
-		allErrs = append(allErrs, validateObjectFieldSelector(ev.ValueFrom.FieldRef, &validFieldPathExpressionsEnv, fldPath.Child("fieldRef"))...)
+		allErrs = append(allErrs, validateObjectFieldSelector(ev.ValueFrom.FieldRef, &validEnvDownwardAPIFieldPathExpressions, fldPath.Child("fieldRef"))...)
 	}
 	if ev.ValueFrom.ResourceFieldRef != nil {
 		numSources++
@@ -1945,15 +1953,35 @@ func validateObjectFieldSelector(fs *core.ObjectFieldSelector, expressions *sets
 
 	if len(fs.APIVersion) == 0 {
 		allErrs = append(allErrs, field.Required(fldPath.Child("apiVersion"), ""))
-	} else if len(fs.FieldPath) == 0 {
+		return allErrs
+	}
+	if len(fs.FieldPath) == 0 {
 		allErrs = append(allErrs, field.Required(fldPath.Child("fieldPath"), ""))
-	} else {
-		internalFieldPath, _, err := legacyscheme.Scheme.ConvertFieldLabel(fs.APIVersion, "Pod", fs.FieldPath, "")
-		if err != nil {
-			allErrs = append(allErrs, field.Invalid(fldPath.Child("fieldPath"), fs.FieldPath, fmt.Sprintf("error converting fieldPath: %v", err)))
-		} else if !expressions.Has(internalFieldPath) {
-			allErrs = append(allErrs, field.NotSupported(fldPath.Child("fieldPath"), internalFieldPath, expressions.List()))
+		return allErrs
+	}
+
+	internalFieldPath, _, err := podshelper.ConvertDownwardAPIFieldLabel(fs.APIVersion, fs.FieldPath, "")
+	if err != nil {
+		allErrs = append(allErrs, field.Invalid(fldPath.Child("fieldPath"), fs.FieldPath, fmt.Sprintf("error converting fieldPath: %v", err)))
+		return allErrs
+	}
+
+	if path, subscript, ok := fieldpath.SplitMaybeSubscriptedPath(internalFieldPath); ok {
+		switch path {
+		case "metadata.annotations":
+			for _, msg := range validation.IsQualifiedName(strings.ToLower(subscript)) {
+				allErrs = append(allErrs, field.Invalid(fldPath, subscript, msg))
+			}
+		case "metadata.labels":
+			for _, msg := range validation.IsQualifiedName(subscript) {
+				allErrs = append(allErrs, field.Invalid(fldPath, subscript, msg))
+			}
+		default:
+			allErrs = append(allErrs, field.Invalid(fldPath, path, "does not support subscript"))
 		}
+	} else if !expressions.Has(path) {
+		allErrs = append(allErrs, field.NotSupported(fldPath.Child("fieldPath"), path, expressions.List()))
+		return allErrs
 	}
 
 	return allErrs