Fix that pod spec's hash may be changed when new fields are added to …

…the `PodSpec` (#6030)

.gitignore

@@ -1,3 +1,4 @@
 _output
 output
 .idea/
+coverage.txt

Makefile

@@ -121,7 +121,7 @@ lint: bin/golangci-lint
 unit:
 	go test $$(go list -e ./... | grep -v cmd | grep -v tools | grep -v tests | grep -v third_party) \
 		-cover -coverprofile=coverage.txt -covermode=atomic
-	sed -i.bak '/generated/d;/fake.go/d' coverage.txt && rm coverage.txt coverage.txt.bak
+	sed -i.bak '/generated/d;/fake.go/d' coverage.txt && rm coverage.txt.bak
 
 .PHONY: check
 check: lint unit verify

pkg/controllers/pd/tasks/pod_test.go

@@ -35,7 +35,10 @@ import (
 	"github.com/pingcap/tidb-operator/pkg/utils/task/v3"
 )
 
-const fakeVersion = "v1.2.3"
+const (
+	fakeVersion         = "v1.2.3"
+	expectedPodSpecHash = "7d4f6bf985"
+)
 
 func TestTaskPod(t *testing.T) {
 	cases := []struct {
@@ -283,7 +286,7 @@ func TestTaskPod(t *testing.T) {
 					pod: fake.FakeObj("aaa-pd-xxx", func(obj *corev1.Pod) *corev1.Pod {
 						obj.Labels = map[string]string{
 							v1alpha1.LabelKeyConfigHash:  "newest",
-							v1alpha1.LabelKeyPodSpecHash: "6d6499ffc7",
+							v1alpha1.LabelKeyPodSpecHash: expectedPodSpecHash,
 						}
 						return obj
 					}),
@@ -331,7 +334,7 @@ func TestTaskPod(t *testing.T) {
 					pod: fake.FakeObj("aaa-pd-xxx", func(obj *corev1.Pod) *corev1.Pod {
 						obj.Labels = map[string]string{
 							v1alpha1.LabelKeyConfigHash:  "newest",
-							v1alpha1.LabelKeyPodSpecHash: "6d6499ffc7",
+							v1alpha1.LabelKeyPodSpecHash: expectedPodSpecHash,
 							"xxx":                        "yyy",
 						}
 						return obj
@@ -382,7 +385,7 @@ func TestTaskPod(t *testing.T) {
 						obj.Labels = map[string]string{
 							v1alpha1.LabelKeyInstance:    "aaa-xxx",
 							v1alpha1.LabelKeyConfigHash:  "newest",
-							v1alpha1.LabelKeyPodSpecHash: "6d6499ffc7",
+							v1alpha1.LabelKeyPodSpecHash: expectedPodSpecHash,
 						}
 						return obj
 					}),

pkg/controllers/tidb/tasks/pod_test.go

@@ -32,7 +32,7 @@ import (
 
 const (
 	fakeVersion = "v1.2.3"
-	podSpecHash = "9bbf8897b"
+	podSpecHash = "fc445b4c6"
 )
 
 func TestTaskPod(t *testing.T) {

pkg/controllers/tiflash/tasks/pod_test.go

@@ -32,7 +32,7 @@ import (
 
 const (
 	fakeVersion = "v1.2.3"
-	fakePodHash = "779dbdbdf4"
+	fakePodHash = "5bf69bf8f9"
 )
 
 func TestTaskPod(t *testing.T) {

pkg/controllers/tikv/tasks/pod_test.go

@@ -33,7 +33,10 @@ import (
 	"github.com/pingcap/tidb-operator/pkg/utils/task/v3"
 )
 
-const fakeVersion = "v1.2.3"
+const (
+	fakeVersion = "v1.2.3"
+	podSpecHash = "5f7b88ffbd"
+)
 
 func TestTaskPod(t *testing.T) {
 	now := metav1.Now()
@@ -173,7 +176,7 @@ func TestTaskPod(t *testing.T) {
 					pod: fake.FakeObj("aaa-tikv-xxx", func(obj *corev1.Pod) *corev1.Pod {
 						obj.Labels = map[string]string{
 							v1alpha1.LabelKeyConfigHash:  "newest",
-							v1alpha1.LabelKeyPodSpecHash: "59f798884b",
+							v1alpha1.LabelKeyPodSpecHash: podSpecHash,
 						}
 						return obj
 					}),
@@ -197,7 +200,7 @@ func TestTaskPod(t *testing.T) {
 					pod: fake.FakeObj("aaa-tikv-xxx", func(obj *corev1.Pod) *corev1.Pod {
 						obj.Labels = map[string]string{
 							v1alpha1.LabelKeyConfigHash:  "old",
-							v1alpha1.LabelKeyPodSpecHash: "59f798884b",
+							v1alpha1.LabelKeyPodSpecHash: podSpecHash,
 						}
 						return obj
 					}),
@@ -221,7 +224,7 @@ func TestTaskPod(t *testing.T) {
 					pod: fake.FakeObj("aaa-tikv-xxx", func(obj *corev1.Pod) *corev1.Pod {
 						obj.Labels = map[string]string{
 							v1alpha1.LabelKeyConfigHash:  "newest",
-							v1alpha1.LabelKeyPodSpecHash: "59f798884b",
+							v1alpha1.LabelKeyPodSpecHash: podSpecHash,
 							"xxx":                        "yyy",
 						}
 						return obj
@@ -246,7 +249,7 @@ func TestTaskPod(t *testing.T) {
 					pod: fake.FakeObj("aaa-tikv-xxx", func(obj *corev1.Pod) *corev1.Pod {
 						obj.Labels = map[string]string{
 							v1alpha1.LabelKeyConfigHash:  "newest",
-							v1alpha1.LabelKeyPodSpecHash: "59f798884b",
+							v1alpha1.LabelKeyPodSpecHash: podSpecHash,
 							"xxx":                        "yyy",
 						}
 						return obj
@@ -272,7 +275,7 @@ func TestTaskPod(t *testing.T) {
 						obj.Labels = map[string]string{
 							v1alpha1.LabelKeyInstance:    "aaa-xxx",
 							v1alpha1.LabelKeyConfigHash:  "newest",
-							v1alpha1.LabelKeyPodSpecHash: "59f798884b",
+							v1alpha1.LabelKeyPodSpecHash: podSpecHash,
 						}
 						return obj
 					}),

pkg/utils/k8s/pod.go

@@ -15,31 +15,54 @@
 package k8s
 
 import (
+	"bytes"
 	"fmt"
 	"hash/fnv"
 
 	corev1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/api/resource"
+	serializerjson "k8s.io/apimachinery/pkg/runtime/serializer/json"
 	"k8s.io/apimachinery/pkg/util/rand"
+	"k8s.io/client-go/kubernetes/scheme"
 
 	"github.com/pingcap/tidb-operator/apis/core/v1alpha1"
 	maputil "github.com/pingcap/tidb-operator/pkg/utils/map"
 	hashutil "github.com/pingcap/tidb-operator/third_party/kubernetes/pkg/util/hash"
 )
 
+var podEncoder = scheme.Codecs.EncoderForVersion(
+	serializerjson.NewSerializerWithOptions(
+		serializerjson.DefaultMetaFactory,
+		scheme.Scheme,
+		scheme.Scheme,
+		serializerjson.SerializerOptions{
+			Yaml:   false,
+			Pretty: false,
+			Strict: true,
+		}),
+	corev1.SchemeGroupVersion,
+)
+
 // CalculateHashAndSetLabels calculate the hash of pod spec and set it to the pod labels.
 func CalculateHashAndSetLabels(pod *corev1.Pod) {
-	hasher := fnv.New32a()
-	if pod.Labels == nil {
-		pod.Labels = map[string]string{}
-	}
 	spec := pod.Spec.DeepCopy()
 	for i := range spec.InitContainers {
 		c := &spec.InitContainers[i]
 		// ignores init containers image change to support hot reload image for sidecar
 		c.Image = ""
 	}
-	hashutil.DeepHashObject(hasher, spec)
+
+	// This prevents the hash from being changed when new fields are added to the `PodSpec` due to K8s version upgrades.
+	buf := bytes.Buffer{}
+	if err := podEncoder.Encode(&corev1.Pod{Spec: *spec}, &buf); err != nil {
+		panic(fmt.Errorf("failed to encode pod spec, %w", err))
+	}
+	hasher := fnv.New32a()
+	hashutil.DeepHashObject(hasher, buf.Bytes())
+
+	if pod.Labels == nil {
+		pod.Labels = map[string]string{}
+	}
 	pod.Labels[v1alpha1.LabelKeyPodSpecHash] = rand.SafeEncodeString(fmt.Sprint(hasher.Sum32()))
 }
 

pkg/utils/k8s/revision/controller_revision.go

@@ -148,6 +148,7 @@ func getPatch(obj client.Object, gvk schema.GroupVersionKind) ([]byte, error) {
 				}),
 			gvk.GroupVersion(),
 		)
+		encoderMap[gvk.GroupVersion()] = encoder
 	}
 
 	buf := bytes.Buffer{}