Remove remaining deps on k8s.io/kubernetes

These are mostly helper code for setting up env vars.  There is a single
file copied verbatim, although much of this downward api stuff is a
copy.  We may want to pull this out and do a direct copy of the the code
so it is easier to update and work with upstream to have a shared
package that lives outside of k8s.io/kubernetes for downward api.

internal/podutils/README.md

@@ -0,0 +1,15 @@
+Much of this is copied from k8s.io/kubernetes, even if it isn't a 1-1 copy of a
+file.  This exists so we do not have to import from k8s.io/kubernetes which is
+currently problematic.  Ideally most or all of this will go away and an upstream
+solution is found so that we can share an implementation with Kubelet without
+importing from k8s.io/kubernetes
+
+
+| filename | upstream location |
+|----------|-------------------|
+| envvars.go | https://github.com/kubernetes/kubernetes/blob/98d5dc5d36d34a7ee13368a7893dcb400ec4e566/pkg/kubelet/envvars/envvars.go#L32 |
+| helper.go#ConvertDownwardAPIFieldLabel | https://github.com/kubernetes/kubernetes/blob/98d5dc5d36d34a7ee13368a7893dcb400ec4e566/pkg/apis/core/pods/helpers.go#L65 |
+| helper.go#ExtractFieldPathAsString | https://github.com/kubernetes/kubernetes/blob/98d5dc5d36d34a7ee13368a7893dcb400ec4e566/pkg/fieldpath/fieldpath.go#L46 |
+| helper.go#SplitMaybeSubscriptedPath | https://github.com/kubernetes/kubernetes/blob/98d5dc5d36d34a7ee13368a7893dcb400ec4e566/pkg/fieldpath/fieldpath.go#L96 |
+| helper.go#FormatMap | https://github.com/kubernetes/kubernetes/blob/ea0764452222146c47ec826977f49d7001b0ea8c/pkg/fieldpath/fieldpath.go#L29 |
+| helper.go#IsServiceIPSet | https://github.com/kubernetes/kubernetes/blob/ea0764452222146c47ec826977f49d7001b0ea8c/pkg/apis/core/v1/helper/helpers.go#L139 |

internal/podutils/env.go

@@ -29,9 +29,6 @@ import (
 	"k8s.io/apimachinery/pkg/util/sets"
 	apivalidation "k8s.io/apimachinery/pkg/util/validation"
 	"k8s.io/client-go/tools/record"
-	podshelper "k8s.io/kubernetes/pkg/apis/core/pods"
-	fieldpath "k8s.io/kubernetes/pkg/fieldpath"
-	"k8s.io/kubernetes/pkg/kubelet/envvars"
 	"k8s.io/utils/pointer"
 )
 
@@ -120,10 +117,6 @@ func populateContainerEnvironment(ctx context.Context, pod *corev1.Pod, containe
 	return nil
 }
 
-func isServiceIPSet(service *corev1.Service) bool {
-	return service.Spec.ClusterIP != corev1.ClusterIPNone && service.Spec.ClusterIP != ""
-}
-
 // getServiceEnvVarMap makes a map[string]string of env vars for services a
 // pod in namespace ns should see.
 // Based on getServiceEnvVarMap in kubelet_pods.go.
@@ -142,7 +135,7 @@ func getServiceEnvVarMap(rm *manager.ResourceManager, ns string, enableServiceLi
 	for i := range services {
 		service := services[i]
 		// ignore services where ClusterIP is "None" or empty
-		if !isServiceIPSet(service) {
+		if !IsServiceIPSet(service) {
 			continue
 		}
 		serviceName := service.Name
@@ -165,7 +158,7 @@ func getServiceEnvVarMap(rm *manager.ResourceManager, ns string, enableServiceLi
 		mappedServices = append(mappedServices, serviceMap[key])
 	}
 
-	for _, e := range envvars.FromServices(mappedServices) {
+	for _, e := range FromServices(mappedServices) {
 		m[e.Name] = e.Value
 	}
 	return m, nil
@@ -489,7 +482,7 @@ func getEnvironmentVariableValueWithValueFromFieldRef(ctx context.Context, env *
 // podFieldSelectorRuntimeValue returns the runtime value of the given
 // selector for a pod.
 func podFieldSelectorRuntimeValue(fs *corev1.ObjectFieldSelector, pod *corev1.Pod) (string, error) {
-	internalFieldPath, _, err := podshelper.ConvertDownwardAPIFieldLabel(fs.APIVersion, fs.FieldPath, "")
+	internalFieldPath, _, err := ConvertDownwardAPIFieldLabel(fs.APIVersion, fs.FieldPath, "")
 	if err != nil {
 		return "", err
 	}
@@ -500,5 +493,5 @@ func podFieldSelectorRuntimeValue(fs *corev1.ObjectFieldSelector, pod *corev1.Po
 		return pod.Spec.ServiceAccountName, nil
 
 	}
-	return fieldpath.ExtractFieldPathAsString(pod, internalFieldPath)
+	return ExtractFieldPathAsString(pod, internalFieldPath)
 }

internal/podutils/envvars.go

@@ -0,0 +1,112 @@
+/*
+Copyright 2014 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 podutils
+
+import (
+	"fmt"
+	"net"
+	"strconv"
+	"strings"
+
+	v1 "k8s.io/api/core/v1"
+)
+
+// FromServices builds environment variables that a container is started with,
+// which tell the container where to find the services it may need, which are
+// provided as an argument.
+func FromServices(services []*v1.Service) []v1.EnvVar {
+	var result []v1.EnvVar
+	for i := range services {
+		service := services[i]
+
+		// ignore services where ClusterIP is "None" or empty
+		// the services passed to this method should be pre-filtered
+		// only services that have the cluster IP set should be included here
+		if !IsServiceIPSet(service) {
+			continue
+		}
+
+		// Host
+		name := makeEnvVariableName(service.Name) + "_SERVICE_HOST"
+		result = append(result, v1.EnvVar{Name: name, Value: service.Spec.ClusterIP})
+		// First port - give it the backwards-compatible name
+		name = makeEnvVariableName(service.Name) + "_SERVICE_PORT"
+		result = append(result, v1.EnvVar{Name: name, Value: strconv.Itoa(int(service.Spec.Ports[0].Port))})
+		// All named ports (only the first may be unnamed, checked in validation)
+		for i := range service.Spec.Ports {
+			sp := &service.Spec.Ports[i]
+			if sp.Name != "" {
+				pn := name + "_" + makeEnvVariableName(sp.Name)
+				result = append(result, v1.EnvVar{Name: pn, Value: strconv.Itoa(int(sp.Port))})
+			}
+		}
+		// Docker-compatible vars.
+		result = append(result, makeLinkVariables(service)...)
+	}
+	return result
+}
+
+func makeEnvVariableName(str string) string {
+	// TODO: If we simplify to "all names are DNS1123Subdomains" this
+	// will need two tweaks:
+	//   1) Handle leading digits
+	//   2) Handle dots
+	return strings.ToUpper(strings.Replace(str, "-", "_", -1))
+}
+
+func makeLinkVariables(service *v1.Service) []v1.EnvVar {
+	prefix := makeEnvVariableName(service.Name)
+	all := []v1.EnvVar{}
+	for i := range service.Spec.Ports {
+		sp := &service.Spec.Ports[i]
+
+		protocol := string(v1.ProtocolTCP)
+		if sp.Protocol != "" {
+			protocol = string(sp.Protocol)
+		}
+
+		hostPort := net.JoinHostPort(service.Spec.ClusterIP, strconv.Itoa(int(sp.Port)))
+
+		if i == 0 {
+			// Docker special-cases the first port.
+			all = append(all, v1.EnvVar{
+				Name:  prefix + "_PORT",
+				Value: fmt.Sprintf("%s://%s", strings.ToLower(protocol), hostPort),
+			})
+		}
+		portPrefix := fmt.Sprintf("%s_PORT_%d_%s", prefix, sp.Port, strings.ToUpper(protocol))
+		all = append(all, []v1.EnvVar{
+			{
+				Name:  portPrefix,
+				Value: fmt.Sprintf("%s://%s", strings.ToLower(protocol), hostPort),
+			},
+			{
+				Name:  portPrefix + "_PROTO",
+				Value: strings.ToLower(protocol),
+			},
+			{
+				Name:  portPrefix + "_PORT",
+				Value: strconv.Itoa(int(sp.Port)),
+			},
+			{
+				Name:  portPrefix + "_ADDR",
+				Value: service.Spec.ClusterIP,
+			},
+		}...)
+	}
+	return all
+}

internal/podutils/helper.go

@@ -0,0 +1,156 @@
+/*
+Copyright 2014 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 podutils
+
+import (
+	"fmt"
+	"strings"
+
+	corev1 "k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/api/meta"
+	"k8s.io/apimachinery/pkg/util/sets"
+	"k8s.io/apimachinery/pkg/util/validation"
+)
+
+// 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 := 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",
+		"status.podIPs":
+		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)
+	}
+}
+
+// ExtractFieldPathAsString extracts the field from the given object
+// and returns it as a string.  The object must be a pointer to an
+// API type.
+func ExtractFieldPathAsString(obj interface{}, fieldPath string) (string, error) {
+	accessor, err := meta.Accessor(obj)
+	if err != nil {
+		return "", err
+	}
+
+	if path, subscript, ok := SplitMaybeSubscriptedPath(fieldPath); ok {
+		switch path {
+		case "metadata.annotations":
+			if errs := validation.IsQualifiedName(strings.ToLower(subscript)); len(errs) != 0 {
+				return "", fmt.Errorf("invalid key subscript in %s: %s", fieldPath, strings.Join(errs, ";"))
+			}
+			return accessor.GetAnnotations()[subscript], nil
+		case "metadata.labels":
+			if errs := validation.IsQualifiedName(subscript); len(errs) != 0 {
+				return "", fmt.Errorf("invalid key subscript in %s: %s", fieldPath, strings.Join(errs, ";"))
+			}
+			return accessor.GetLabels()[subscript], nil
+		default:
+			return "", fmt.Errorf("fieldPath %q does not support subscript", fieldPath)
+		}
+	}
+
+	switch fieldPath {
+	case "metadata.annotations":
+		return FormatMap(accessor.GetAnnotations()), nil
+	case "metadata.labels":
+		return FormatMap(accessor.GetLabels()), nil
+	case "metadata.name":
+		return accessor.GetName(), nil
+	case "metadata.namespace":
+		return accessor.GetNamespace(), nil
+	case "metadata.uid":
+		return string(accessor.GetUID()), nil
+	}
+
+	return "", fmt.Errorf("unsupported fieldPath: %v", fieldPath)
+}
+
+// SplitMaybeSubscriptedPath checks whether the specified fieldPath is
+// subscripted, and
+//  - if yes, this function splits the fieldPath into path and subscript, and
+//    returns (path, subscript, true).
+//  - if no, this function returns (fieldPath, "", false).
+//
+// Example inputs and outputs:
+//  - "metadata.annotations['myKey']" --> ("metadata.annotations", "myKey", true)
+//  - "metadata.annotations['a[b]c']" --> ("metadata.annotations", "a[b]c", true)
+//  - "metadata.labels['']"           --> ("metadata.labels", "", true)
+//  - "metadata.labels"               --> ("metadata.labels", "", false)
+func SplitMaybeSubscriptedPath(fieldPath string) (string, string, bool) {
+	if !strings.HasSuffix(fieldPath, "']") {
+		return fieldPath, "", false
+	}
+	s := strings.TrimSuffix(fieldPath, "']")
+	parts := strings.SplitN(s, "['", 2)
+	if len(parts) < 2 {
+		return fieldPath, "", false
+	}
+	if len(parts[0]) == 0 {
+		return fieldPath, "", false
+	}
+	return parts[0], parts[1], true
+}
+
+// FormatMap formats map[string]string to a string.
+func FormatMap(m map[string]string) (fmtStr string) {
+	// output with keys in sorted order to provide stable output
+	keys := sets.NewString()
+	for key := range m {
+		keys.Insert(key)
+	}
+	for _, key := range keys.List() {
+		fmtStr += fmt.Sprintf("%v=%q\n", key, m[key])
+	}
+	fmtStr = strings.TrimSuffix(fmtStr, "\n")
+
+	return
+}
+
+// IsServiceIPSet aims to check if the service's ClusterIP is set or not the objective is not to perform validation here
+func IsServiceIPSet(service *corev1.Service) bool {
+	return service.Spec.ClusterIP != corev1.ClusterIPNone && service.Spec.ClusterIP != ""
+}