Merge pull request #50932 from yguo0905/stats-cadvisor

Automatic merge from submit-queue (batch tested with PRs 50932, 49610, 51312, 51415, 50705)

Implement StatsProvider interface using cadvisor

Ref: https://github.com/kubernetes/kubernetes/issues/46984

- This PR changes the `StatsProvider` interface in `pkg/kubelet/server/stats` so that it can provide container stats from either cadvisor or CRI, and the summary API can consume the stats without knowing how they are provided.
- The `StatsProvider` struct in the newly added package `pkg/kubelet/stats` implements part of the `StatsProvider` interface in `pkg/kubelet/server/stats`.
- In `pkg/kubelet/stats`,
    - `stats_provider.go`: implements the node level stats and provides the entry point for this package.
    - `cadvisor_stats_provider.go`: implements the container level stats using cadvisor.
    - `cri_stats_provider.go`: implements the container level stats using CRI.
    - `helper.go`: utility functions shared by the above three components.
- There should be no user visible behaviors change in this PR.
- A follow up PR will implement the StatsProvider interface using CRI.

**Release note**:
```
None
```

/assign @yujuhong 
/assign @WIZARD-CXY

pkg/kubelet/kubelet_test.go

@@ -60,7 +60,8 @@ import (
 	proberesults "k8s.io/kubernetes/pkg/kubelet/prober/results"
 	probetest "k8s.io/kubernetes/pkg/kubelet/prober/testing"
 	"k8s.io/kubernetes/pkg/kubelet/secret"
-	"k8s.io/kubernetes/pkg/kubelet/server/stats"
+	serverstats "k8s.io/kubernetes/pkg/kubelet/server/stats"
+	"k8s.io/kubernetes/pkg/kubelet/stats"
 	"k8s.io/kubernetes/pkg/kubelet/status"
 	statustest "k8s.io/kubernetes/pkg/kubelet/status/testing"
 	kubetypes "k8s.io/kubernetes/pkg/kubelet/types"
@@ -261,7 +262,7 @@ func newTestKubeletWithImageList(
 
 	// TODO: Factor out "StatsProvider" from Kubelet so we don't have a cyclic dependency
 	volumeStatsAggPeriod := time.Second * 10
-	kubelet.resourceAnalyzer = stats.NewResourceAnalyzer(kubelet, volumeStatsAggPeriod, kubelet.containerRuntime)
+	kubelet.resourceAnalyzer = serverstats.NewResourceAnalyzer(kubelet, volumeStatsAggPeriod)
 	nodeRef := &v1.ObjectReference{
 		Kind:      "Node",
 		Name:      string(kubelet.nodeName),
@@ -304,6 +305,12 @@ func newTestKubeletWithImageList(
 	kubelet.AddPodSyncLoopHandler(activeDeadlineHandler)
 	kubelet.AddPodSyncHandler(activeDeadlineHandler)
 	kubelet.gpuManager = gpu.NewGPUManagerStub()
+	kubelet.StatsProvider = stats.NewCadvisorStatsProvider(
+		kubelet.cadvisor,
+		kubelet.resourceAnalyzer,
+		kubelet.podManager,
+		kubelet.runtimeCache,
+		fakeRuntime)
 	return &TestKubelet{kubelet, fakeRuntime, mockCadvisor, fakeKubeClient, fakeMirrorClient, fakeClock, nil, plug}
 }