Automatic merge from submit-queue (batch tested with PRs 51590, 48217, 51209, 51575, 48627)
Skip system container cgroup stats if undefined
**What this PR does / why we need it**:
the kubelet /stats/summary endpoint tried to look up cgroup stats for containers that are not required. this polluted logs with messages about not finding stats for "" container. this pr skips cgroup stats if the cgroup name is not specified (they are optional anyway)
**Special notes for your reviewer**:
i think this was a regression from recent refactor.
**Release note**:
```release-note
NONE
```
For pod volumes that reference a PVC, add a PVCRef to the corresponding
volume stat. This allows metrics to be indexed/queried by PVC name
which is more user-friendly than Pod reference
Automatic merge from submit-queue
Remove the status of the terminated containers in the summary endpoint
Ref: https://github.com/kubernetes/kubernetes/issues/47853
- When building summary, a container is considered to be terminated if it has an older creation time and no CPU instantaneous or memory RSS usage.
- We remove the terminated containers in the summary by grouping the containers with the same name in the same pod, sorting them in each group by creation time, and skipping the oldest ones with no usage in each group. Let me know if there's simpler way.
**Release note**:
```
None
```
/assign @yujuhong
Automatic merge from submit-queue
Add assert.NotNil for test case
I hardcode the `DefaultInterfaceName` from `eth0` to `eth-k8sdefault` at release 1.2.0, in order to test my CNI plugins. When running the test, it panics and prints wrongly formatted messages as below.
In the test case `TestBuildSummary`, `containerInfoV2ToNetworkStats` will return `nil` if `DefaultInterfaceName` is not `eth0`. So maybe we should add `assert.NotNil` to the test case.
```
ok k8s.io/kubernetes/pkg/kubelet/server 0.591s
W0523 03:25:28.257074 2257 summary.go:311] Missing default interface "eth-k8sdefault" for s%!(EXTRA string=node:FooNode)
W0523 03:25:28.257322 2257 summary.go:311] Missing default interface "eth-k8sdefault" for s%!(EXTRA string=pod:test0_pod1)
W0523 03:25:28.257361 2257 summary.go:311] Missing default interface "eth-k8sdefault" for s%!(EXTRA string=pod:test0_pod0)
W0523 03:25:28.257419 2257 summary.go:311] Missing default interface "eth-k8sdefault" for s%!(EXTRA string=pod:test2_pod0)
--- FAIL: TestBuildSummary (0.00s)
panic: runtime error: invalid memory address or nil pointer dereference [recovered]
panic: runtime error: invalid memory address or nil pointer dereference
[signal 0xb code=0x1 addr=0x0 pc=0x471817]
goroutine 16 [running]:
testing.func·006()
/usr/src/go/src/testing/testing.go:441 +0x181
k8s.io/kubernetes/pkg/kubelet/server/stats.checkNetworkStats(0xc20806d3b0, 0x140bbc0, 0x4, 0x0, 0x0)
/go/src/k8s.io/kubernetes/_output/dockerized/go/src/k8s.io/kubernetes/pkg/kubelet/server/stats/summary_test.go:296 +0xc07
k8s.io/kubernetes/pkg/kubelet/server/stats.TestBuildSummary(0xc20806d3b0)
/go/src/k8s.io/kubernetes/_output/dockerized/go/src/k8s.io/kubernetes/pkg/kubelet/server/stats/summary_test.go:124 +0x11d2
testing.tRunner(0xc20806d3b0, 0x1e43180)
/usr/src/go/src/testing/testing.go:447 +0xbf
created by testing.RunTests
/usr/src/go/src/testing/testing.go:555 +0xa8b
```
