fix: unit test issue, k8s 1.20-1.22 compatibility (#311)

* fix: unit test issue, k8s 1.20-1.22 compatibility

* fix: lint issue

Author: Code2Life

.gitignore

@@ -35,4 +35,6 @@ prompts/*
 
 tmp*
 
-__debug*
+__debug*
+
+vendor

cmd/main.go

@@ -28,6 +28,7 @@ import (
 	// Import all Kubernetes client auth plugins (e.g. Azure, GCP, OIDC, etc.)
 	// to ensure that exec-entrypoint and run can make use of them.
 
+	"k8s.io/client-go/kubernetes"
 	_ "k8s.io/client-go/plugin/pkg/client/auth"
 	"k8s.io/client-go/rest"
 	"k8s.io/klog/v2"
@@ -187,6 +188,21 @@ func main() {
 		os.Exit(1)
 	}
 
+	k8sClient, err := kubernetes.NewForConfig(kc)
+	if err != nil {
+		setupLog.Error(err, "unable to create k8s client")
+		os.Exit(1)
+	}
+	version, err := k8sClient.Discovery().ServerVersion()
+	if err != nil {
+		setupLog.Error(err, "unable to get k8s version")
+		os.Exit(1)
+	}
+	// set env for feature gating, so that to be compatible with different k8s version
+	setupLog.Info("detected API server version for feature gating", "version", version.String())
+	_ = os.Setenv(constants.KubeApiVersionMajorEnv, version.Major)
+	_ = os.Setenv(constants.KubeApiVersionMinorEnv, version.Minor)
+
 	setupTimeSeriesAndWatchGlobalConfigChanges(ctx, mgr)
 
 	if autoScaleCanBeEnabled && enableAutoScale {

dockerfile/operator.Dockerfile

@@ -10,7 +10,7 @@ COPY go.mod go.mod
 COPY go.sum go.sum
 # cache deps before building and copying source so that we don't need to re-download as much
 # and so that source changes don't invalidate our downloaded layer
-RUN go mod download
+RUN go mod vendor
 
 # Copy the go source
 COPY cmd/ cmd/
@@ -19,6 +19,9 @@ COPY internal/ internal/
 # Copy .git directory to enable VCS info in build
 COPY .git/ .git/
 
+COPY scripts/ scripts/
+COPY patches/ patches/
+RUN bash ./scripts/patch-scheduler.sh
 
 # Build
 # the GOARCH has not a default value to allow the binary be built according to the host where the command

internal/constants/env.go

@@ -142,3 +142,8 @@ const (
 	NodeDiscoveryReportGPUNodeEnvName = "NODE_DISCOVERY_REPORT_GPU_NODE"
 	NodeDiscoveryHostNameEnv          = "HOSTNAME"
 )
+
+const (
+	KubeApiVersionMajorEnv = "KUBE_API_VERSION_MAJOR"
+	KubeApiVersionMinorEnv = "KUBE_API_VERSION_MINOR"
+)

internal/controller/pod_controller_test.go

@@ -82,13 +82,17 @@ var _ = Describe("Pod Controller", func() {
 							Image: "test-image",
 						},
 					},
+					TerminationGracePeriodSeconds: ptr.To(int64(0)),
 				},
 			}
 		})
 
 		AfterEach(func() {
 			if workerPod != nil {
 				_ = k8sClient.Delete(ctx, workerPod)
+				Eventually(func() error {
+					return k8sClient.Get(ctx, client.ObjectKeyFromObject(workerPod), workerPod)
+				}).Should(Satisfy(errors.IsNotFound))
 			}
 		})
 
@@ -394,9 +398,15 @@ var _ = Describe("Pod Controller", func() {
 		AfterEach(func() {
 			if workload != nil {
 				_ = k8sClient.Delete(ctx, workload)
+				Eventually(func() error {
+					return k8sClient.Get(ctx, client.ObjectKeyFromObject(workload), workload)
+				}).Should(Satisfy(errors.IsNotFound))
 			}
 			if pod != nil {
 				_ = k8sClient.Delete(ctx, pod)
+				Eventually(func() error {
+					return k8sClient.Get(ctx, client.ObjectKeyFromObject(pod), pod)
+				}).Should(Satisfy(errors.IsNotFound))
 			}
 		})
 

patches/scheduler-csi-capacity-1.patch

@@ -0,0 +1,32 @@
+--- ../vendor/k8s.io/kubernetes/pkg/scheduler/framework/plugins/volumebinding/volume_binding.go	2025-08-06 16:50:24
++++ ../vendor/k8s.io/kubernetes/pkg/scheduler/framework/plugins/volumebinding/volume_binding.go	2025-08-06 16:51:16
+@@ -20,6 +20,8 @@
+ 	"context"
+ 	"errors"
+ 	"fmt"
++	"os"
++	"strconv"
+ 	"sync"
+ 	"time"
+ 
+@@ -603,9 +605,18 @@
+ 	storageClassInformer := fh.SharedInformerFactory().Storage().V1().StorageClasses()
+ 	csiNodeInformer := fh.SharedInformerFactory().Storage().V1().CSINodes()
+ 	capacityCheck := CapacityCheck{
+-		CSIDriverInformer:          fh.SharedInformerFactory().Storage().V1().CSIDrivers(),
+-		CSIStorageCapacityInformer: fh.SharedInformerFactory().Storage().V1().CSIStorageCapacities(),
++		CSIDriverInformer: fh.SharedInformerFactory().Storage().V1().CSIDrivers(),
+ 	}
++
++	// FIX kubernetes 1.24 and lower version API missing issue
++	minorVersionStr := os.Getenv("KUBE_API_VERSION_MINOR")
++	if minorVersionStr != "" {
++		minorVersion, err := strconv.Atoi(minorVersionStr)
++		if err == nil && minorVersion >= 24 {
++			capacityCheck.CSIStorageCapacityInformer = fh.SharedInformerFactory().Storage().V1().CSIStorageCapacities()
++		}
++	}
++
+ 	binder := NewVolumeBinder(klog.FromContext(ctx), fh.ClientSet(), fts, podInformer, nodeInformer, csiNodeInformer, pvcInformer, pvInformer, storageClassInformer, capacityCheck, time.Duration(args.BindTimeoutSeconds)*time.Second)
+ 
+ 	// build score function

patches/scheduler-csi-capacity-2.patch

@@ -0,0 +1,27 @@
+--- ../vendor/k8s.io/kubernetes/pkg/scheduler/framework/plugins/volumebinding/binder.go	2025-08-06 17:00:36
++++ ../vendor/k8s.io/kubernetes/pkg/scheduler/framework/plugins/volumebinding/binder.go	2025-08-06 17:00:27
+@@ -269,7 +269,11 @@
+ 	}
+ 
+ 	b.csiDriverLister = capacityCheck.CSIDriverInformer.Lister()
+-	b.csiStorageCapacityLister = capacityCheck.CSIStorageCapacityInformer.Lister()
++
++	// FIX kubernetes 1.24 and lower version API missing issue
++	if capacityCheck.CSIStorageCapacityInformer != nil {
++		b.csiStorageCapacityLister = capacityCheck.CSIStorageCapacityInformer.Lister()
++	}
+ 
+ 	return b
+ }
+@@ -988,6 +992,11 @@
+ 		return true, nil, nil
+ 	}
+ 
++	// FIX kubernetes 1.24 and lower version API missing issue
++	if b.csiStorageCapacityLister == nil {
++		return true, nil, nil
++	}
++
+ 	// Look for a matching CSIStorageCapacity object(s).
+ 	// TODO (for beta): benchmark this and potentially introduce some kind of lookup structure (https://github.com/kubernetes/enhancements/issues/1698#issuecomment-654356718).
+ 	capacities, err := b.csiStorageCapacityLister.List(labels.Everything())

patches/scheduler-csi-capacity-3.patch

@@ -0,0 +1,26 @@
+--- ../vendor/k8s.io/kubernetes/pkg/scheduler/eventhandlers.go	2025-08-06 17:55:42
++++ ../vendor/k8s.io/kubernetes/pkg/scheduler/eventhandlers.go	2025-08-06 17:56:13
+@@ -19,6 +19,8 @@
+ import (
+ 	"context"
+ 	"fmt"
++	"os"
++	"strconv"
+ 	"strings"
+ 	"time"
+ 
+@@ -514,6 +516,14 @@
+ 			}
+ 			handlers = append(handlers, handlerRegistration)
+ 		case framework.CSIStorageCapacity:
++			// FIX kubernetes 1.24 and lower version API missing issue
++			minorVersionStr := os.Getenv("KUBE_API_VERSION_MINOR")
++			if minorVersionStr != "" {
++				minorVersion, err := strconv.Atoi(minorVersionStr)
++				if err != nil || minorVersion < 24 {
++					continue
++				}
++			}
+ 			if handlerRegistration, err = informerFactory.Storage().V1().CSIStorageCapacities().Informer().AddEventHandler(
+ 				buildEvtResHandler(at, framework.CSIStorageCapacity),
+ 			); err != nil {

patches/scheduler-pdb-1.patch

@@ -0,0 +1,26 @@
+--- ../vendor/k8s.io/kubernetes/pkg/scheduler/framework/plugins/defaultpreemption/default_preemption.go	2025-08-06 17:45:27
++++ ../vendor/k8s.io/kubernetes/pkg/scheduler/framework/plugins/defaultpreemption/default_preemption.go	2025-08-06 17:45:19
+@@ -20,7 +20,9 @@
+ 	"context"
+ 	"fmt"
+ 	"math/rand"
++	"os"
+ 	"sort"
++	"strconv"
+ 
+ 	v1 "k8s.io/api/core/v1"
+ 	policy "k8s.io/api/policy/v1"
+@@ -364,5 +366,13 @@
+ }
+ 
+ func getPDBLister(informerFactory informers.SharedInformerFactory) policylisters.PodDisruptionBudgetLister {
++	// FIX kubernetes 1.21 and lower version API missing issue
++	minorVersionStr := os.Getenv("KUBE_API_VERSION_MINOR")
++	if minorVersionStr != "" {
++		minorVersion, err := strconv.Atoi(minorVersionStr)
++		if err != nil || minorVersion < 21 {
++			return nil
++		}
++	}
+ 	return informerFactory.Policy().V1().PodDisruptionBudgets().Lister()
+ }

patches/scheduler-pdb-2.patch

@@ -0,0 +1,37 @@
+--- ../vendor/k8s.io/kubernetes/pkg/scheduler/framework/preemption/preemption.go	2025-08-06 17:48:23
++++ ../vendor/k8s.io/kubernetes/pkg/scheduler/framework/preemption/preemption.go	2025-08-06 17:48:13
+@@ -21,6 +21,8 @@
+ 	"errors"
+ 	"fmt"
+ 	"math"
++	"os"
++	"strconv"
+ 	"sync"
+ 	"sync/atomic"
+ 	"time"
+@@ -34,6 +36,7 @@
+ 	"k8s.io/apimachinery/pkg/util/sets"
+ 	corelisters "k8s.io/client-go/listers/core/v1"
+ 	policylisters "k8s.io/client-go/listers/policy/v1"
++	policyv1 "k8s.io/client-go/listers/policy/v1"
+ 	corev1helpers "k8s.io/component-helpers/scheduling/corev1"
+ 	"k8s.io/klog/v2"
+ 	extenderv1 "k8s.io/kube-scheduler/extender/v1"
+@@ -145,7 +148,16 @@
+ 
+ func NewEvaluator(pluginName string, fh framework.Handle, i Interface, enableAsyncPreemption bool) *Evaluator {
+ 	podLister := fh.SharedInformerFactory().Core().V1().Pods().Lister()
+-	pdbLister := fh.SharedInformerFactory().Policy().V1().PodDisruptionBudgets().Lister()
++
++	// FIX kubernetes 1.21 and lower version API missing issue
++	var pdbLister policyv1.PodDisruptionBudgetLister
++	minorVersionStr := os.Getenv("KUBE_API_VERSION_MINOR")
++	if minorVersionStr != "" {
++		minorVersion, err := strconv.Atoi(minorVersionStr)
++		if err == nil && minorVersion >= 21 {
++			pdbLister = fh.SharedInformerFactory().Policy().V1().PodDisruptionBudgets().Lister()
++		}
++	}
+ 
+ 	ev := &Evaluator{
+ 		PluginName:            pluginName,