add utils to patch pod status

pkg/util/BUILD

@@ -45,6 +45,7 @@ filegroup(
         "//pkg/util/nsenter:all-srcs",
         "//pkg/util/oom:all-srcs",
         "//pkg/util/parsers:all-srcs",
+        "//pkg/util/pod:all-srcs",
         "//pkg/util/pointer:all-srcs",
         "//pkg/util/procfs:all-srcs",
         "//pkg/util/reflector/prometheus:all-srcs",

pkg/util/pod/BUILD

@@ -0,0 +1,39 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library", "go_test")
+
+go_library(
+    name = "go_default_library",
+    srcs = ["pod.go"],
+    importpath = "k8s.io/kubernetes/pkg/util/pod",
+    visibility = ["//visibility:public"],
+    deps = [
+        "//vendor/k8s.io/api/core/v1:go_default_library",
+        "//vendor/k8s.io/apimachinery/pkg/types:go_default_library",
+        "//vendor/k8s.io/apimachinery/pkg/util/strategicpatch:go_default_library",
+        "//vendor/k8s.io/client-go/kubernetes:go_default_library",
+    ],
+)
+
+go_test(
+    name = "go_default_test",
+    srcs = ["pod_test.go"],
+    embed = [":go_default_library"],
+    deps = [
+        "//vendor/k8s.io/api/core/v1:go_default_library",
+        "//vendor/k8s.io/apimachinery/pkg/apis/meta/v1:go_default_library",
+        "//vendor/k8s.io/client-go/kubernetes/fake: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/util/pod/pod.go

@@ -0,0 +1,63 @@
+/*
+Copyright 2018 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 pod
+
+import (
+	"encoding/json"
+	"fmt"
+
+	"k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/types"
+	"k8s.io/apimachinery/pkg/util/strategicpatch"
+	clientset "k8s.io/client-go/kubernetes"
+)
+
+// PatchPodStatus patches pod status.
+func PatchPodStatus(c clientset.Interface, namespace, name string, oldPodStatus, newPodStatus v1.PodStatus) (*v1.Pod, []byte, error) {
+	patchBytes, err := preparePatchBytesforPodStatus(namespace, name, oldPodStatus, newPodStatus)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	updatedPod, err := c.CoreV1().Pods(namespace).Patch(name, types.StrategicMergePatchType, patchBytes, "status")
+	if err != nil {
+		return nil, nil, fmt.Errorf("failed to patch status %q for pod %q/%q: %v", patchBytes, namespace, name, err)
+	}
+	return updatedPod, patchBytes, nil
+}
+
+func preparePatchBytesforPodStatus(namespace, name string, oldPodStatus, newPodStatus v1.PodStatus) ([]byte, error) {
+	oldData, err := json.Marshal(v1.Pod{
+		Status: oldPodStatus,
+	})
+	if err != nil {
+		return nil, fmt.Errorf("failed to Marshal oldData for pod %q/%q: %v", namespace, name, err)
+	}
+
+	newData, err := json.Marshal(v1.Pod{
+		Status: newPodStatus,
+	})
+	if err != nil {
+		return nil, fmt.Errorf("failed to Marshal newData for pod %q/%q: %v", namespace, name, err)
+	}
+
+	patchBytes, err := strategicpatch.CreateTwoWayMergePatch(oldData, newData, v1.Pod{})
+	if err != nil {
+		return nil, fmt.Errorf("failed to CreateTwoWayMergePatch for pod %q/%q: %v", namespace, name, err)
+	}
+	return patchBytes, nil
+}

pkg/util/pod/pod_test.go

@@ -0,0 +1,116 @@
+/*
+Copyright 2018 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 pod
+
+import (
+	"testing"
+
+	"fmt"
+	"k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/client-go/kubernetes/fake"
+	"reflect"
+)
+
+func TestPatchPodStatus(t *testing.T) {
+	ns := "ns"
+	name := "name"
+	client := &fake.Clientset{}
+	client.CoreV1().Pods(ns).Create(&v1.Pod{
+		ObjectMeta: metav1.ObjectMeta{
+			Namespace: ns,
+			Name:      name,
+		},
+	})
+
+	testCases := []struct {
+		description        string
+		mutate             func(input v1.PodStatus) v1.PodStatus
+		expectedPatchBytes []byte
+	}{
+		{
+			"no change",
+			func(input v1.PodStatus) v1.PodStatus { return input },
+			[]byte(fmt.Sprintf(`{}`)),
+		},
+		{
+			"message change",
+			func(input v1.PodStatus) v1.PodStatus {
+				input.Message = "random message"
+				return input
+			},
+			[]byte(fmt.Sprintf(`{"status":{"message":"random message"}}`)),
+		},
+		{
+			"pod condition change",
+			func(input v1.PodStatus) v1.PodStatus {
+				input.Conditions[0].Status = v1.ConditionFalse
+				return input
+			},
+			[]byte(fmt.Sprintf(`{"status":{"$setElementOrder/conditions":[{"type":"Ready"},{"type":"PodScheduled"}],"conditions":[{"status":"False","type":"Ready"}]}}`)),
+		},
+		{
+			"additional init container condition",
+			func(input v1.PodStatus) v1.PodStatus {
+				input.InitContainerStatuses = []v1.ContainerStatus{
+					{
+						Name:  "init-container",
+						Ready: true,
+					},
+				}
+				return input
+			},
+			[]byte(fmt.Sprintf(`{"status":{"initContainerStatuses":[{"image":"","imageID":"","lastState":{},"name":"init-container","ready":true,"restartCount":0,"state":{}}]}}`)),
+		},
+	}
+	for _, tc := range testCases {
+		_, patchBytes, err := PatchPodStatus(client, ns, name, getPodStatus(), tc.mutate(getPodStatus()))
+		if err != nil {
+			t.Errorf("unexpected error: %v", err)
+		}
+		if !reflect.DeepEqual(patchBytes, tc.expectedPatchBytes) {
+			t.Errorf("for test case %q, expect patchBytes: %q, got: %q\n", tc.description, tc.expectedPatchBytes, patchBytes)
+		}
+	}
+}
+
+func getPodStatus() v1.PodStatus {
+	return v1.PodStatus{
+		Phase: v1.PodRunning,
+		Conditions: []v1.PodCondition{
+			{
+				Type:   v1.PodReady,
+				Status: v1.ConditionTrue,
+			},
+			{
+				Type:   v1.PodScheduled,
+				Status: v1.ConditionTrue,
+			},
+		},
+		ContainerStatuses: []v1.ContainerStatus{
+			{
+				Name:  "container1",
+				Ready: true,
+			},
+			{
+				Name:  "container2",
+				Ready: true,
+			},
+		},
+		Message: "Message",
+	}
+}