Merge pull request #51423 from jiaxuanzhou/imageGC

Automatic merge from submit-queue (batch tested with PRs 51423, 53880). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

Disable ImageGC  when high threshold is set to 100

**What this PR does / why we need it**:

**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: 
fixes #51268 

**Special notes for your reviewer**:

**Release note**:

```release-note
NONE
```

pkg/kubelet/kubelet.go

@@ -1266,6 +1266,14 @@ func (kl *Kubelet) StartGarbageCollection() {
 		}
 	}, ContainerGCPeriod, wait.NeverStop)
 
+	stopChan := make(chan struct{})
+	defer close(stopChan)
+	// when the high threshold is set to 100, stub the image GC manager
+	if kl.kubeletConfiguration.ImageGCHighThresholdPercent == 100 {
+		glog.V(2).Infof("ImageGCHighThresholdPercent is set 100, Disable image GC")
+		go func() { stopChan <- struct{}{} }()
+	}
+
 	prevImageGCFailed := false
 	go wait.Until(func() {
 		if err := kl.imageManager.GarbageCollect(); err != nil {
@@ -1286,7 +1294,7 @@ func (kl *Kubelet) StartGarbageCollection() {
 
 			glog.V(vLevel).Infof("Image garbage collection succeeded")
 		}
-	}, ImageGCPeriod, wait.NeverStop)
+	}, ImageGCPeriod, stopChan)
 }
 
 // initializeModules will initialize internal modules that do not require the container runtime to be up.