fix nil pointer dereference when EventedPLEG is enabled

[pacoxu]

What type of PR is this?

/kind bug

What this PR does / why we need it:

My test ENV is v1.29.0 with AllBeta: true including evented PLEG.

featureGates:
  AllBeta: true
  EventedPLEG: true

Log panic

12月 25 16:02:37 daocloud kubelet[22154]: E1225 16:02:37.233805   22154 kuberuntime_manager.go:1456] "PodSandboxStatus of sandbox for pod" err="rpc error: code = Unknown desc = failed to get sandbox ip: check network namespace closed: remove netns: unlinkat /var/run/netns/cni-69bc2682-2d1a-694c-2a43-276d3e693ea6: device or resource busy" podSandboxID="313ce8e172c9d0de6da0c25a9a05e4b4703445ee30159237d6c07ac577cdb03e" pod="calico-system/calico-kube-controllers-57c5f9d79c-nqdxx"
12月 25 16:02:37 daocloud kubelet[22154]: E1225 16:02:37.233866   22154 generic.go:453] "PLEG: Write status" err="rpc error: code = Unknown desc = failed to get sandbox ip: check network namespace closed: remove netns: unlinkat /var/run/netns/cni-69bc2682-2d1a-694c-2a43-276d3e693ea6: device or resource busy" pod="calico-system/calico-kube-controllers-57c5f9d79c-nqdxx"
12月 25 16:02:37 daocloud kubelet[22154]: E1225 16:02:37.234031   22154 runtime.go:79] Observed a panic: "invalid memory address or nil pointer dereference" (runtime error: invalid memory address or nil pointer dereference)
12月 25 16:02:37 daocloud kubelet[22154]: goroutine 419 [running]:
12月 25 16:02:37 daocloud kubelet[22154]: k8s.io/apimachinery/pkg/util/runtime.logPanic({0x3c742e0?, 0x6e6ad40})
12月 25 16:02:37 daocloud kubelet[22154]:         vendor/k8s.io/apimachinery/pkg/util/runtime/runtime.go:75 +0x85
12月 25 16:02:37 daocloud kubelet[22154]: k8s.io/apimachinery/pkg/util/runtime.HandleCrash({0x0, 0x0, 0x6eb7920?})
12月 25 16:02:37 daocloud kubelet[22154]:         vendor/k8s.io/apimachinery/pkg/util/runtime/runtime.go:49 +0x6b
12月 25 16:02:37 daocloud kubelet[22154]: panic({0x3c742e0?, 0x6e6ad40?})
12月 25 16:02:37 daocloud kubelet[22154]:         /usr/local/go/src/runtime/panic.go:914 +0x21f
12月 25 16:02:37 daocloud kubelet[22154]: k8s.io/kubernetes/pkg/kubelet/pleg.(*GenericPLEG).updateCache(0xc000a86750, {0x4c40048, 0x6ee85c0}, 0xc0006c6380, {0xc00141e330, 0x24})
12月 25 16:02:37 daocloud kubelet[22154]:         pkg/kubelet/pleg/generic.go:479 +0x7ac
12月 25 16:02:37 daocloud kubelet[22154]: k8s.io/kubernetes/pkg/kubelet/pleg.(*GenericPLEG).Relist(0xc000a86750)
12月 25 16:02:37 daocloud kubelet[22154]:         pkg/kubelet/pleg/generic.go:283 +0x815
12月 25 16:02:37 daocloud kubelet[22154]: k8s.io/apimachinery/pkg/util/wait.BackoffUntil.func1(0x30?)
12月 25 16:02:37 daocloud kubelet[22154]:         vendor/k8s.io/apimachinery/pkg/util/wait/backoff.go:226 +0x33
12月 25 16:02:37 daocloud kubelet[22154]: k8s.io/apimachinery/pkg/util/wait.BackoffUntil(0x0?, {0x4c0f620, 0xc000fd5b90}, 0x1, 0xc00020cfc0)
12月 25 16:02:37 daocloud kubelet[22154]:         vendor/k8s.io/apimachinery/pkg/util/wait/backoff.go:227 +0xaf
12月 25 16:02:37 daocloud kubelet[22154]: k8s.io/apimachinery/pkg/util/wait.JitterUntil(0xc000095fb0?, 0x45d964b800, 0x0, 0x0?, 0x4475bc?)
12月 25 16:02:37 daocloud kubelet[22154]:         vendor/k8s.io/apimachinery/pkg/util/wait/backoff.go:204 +0x7f
12月 25 16:02:37 daocloud kubelet[22154]: k8s.io/apimachinery/pkg/util/wait.Until(0xa946c5?, 0xa8f505?, 0xc000b11390?)
12月 25 16:02:37 daocloud kubelet[22154]:         vendor/k8s.io/apimachinery/pkg/util/wait/backoff.go:161 +0x1e
12月 25 16:02:37 daocloud kubelet[22154]: created by k8s.io/kubernetes/pkg/kubelet/pleg.(*GenericPLEG).Start in goroutine 234
12月 25 16:02:37 daocloud kubelet[22154]:         pkg/kubelet/pleg/generic.go:146 +0x185
12月 25 16:02:37 daocloud kubelet[22154]: panic: runtime error: invalid memory address or nil pointer dereference [recovered]
12月 25 16:02:37 daocloud kubelet[22154]:         panic: runtime error: invalid memory address or nil pointer dereference
12月 25 16:02:37 daocloud kubelet[22154]: [signal SIGSEGV: segmentation violation code=0x1 addr=0x78 pc=0x350b6ec]
12月 25 16:02:37 daocloud kubelet[22154]: goroutine 419 [running]:
12月 25 16:02:37 daocloud kubelet[22154]: k8s.io/apimachinery/pkg/util/runtime.HandleCrash({0x0, 0x0, 0x6eb7920?})
12月 25 16:02:37 daocloud kubelet[22154]:         vendor/k8s.io/apimachinery/pkg/util/runtime/runtime.go:56 +0xcd
12月 25 16:02:37 daocloud kubelet[22154]: panic({0x3c742e0?, 0x6e6ad40?})
12月 25 16:02:37 daocloud kubelet[22154]:         /usr/local/go/src/runtime/panic.go:914 +0x21f
12月 25 16:02:37 daocloud kubelet[22154]: k8s.io/kubernetes/pkg/kubelet/pleg.(*GenericPLEG).updateCache(0xc000a86750, {0x4c40048, 0x6ee85c0}, 0xc0006c6380, {0xc00141e330, 0x24})
12月 25 16:02:37 daocloud kubelet[22154]:         pkg/kubelet/pleg/generic.go:479 +0x7ac
12月 25 16:02:37 daocloud kubelet[22154]: k8s.io/kubernetes/pkg/kubelet/pleg.(*GenericPLEG).Relist(0xc000a86750)
12月 25 16:02:37 daocloud kubelet[22154]:         pkg/kubelet/pleg/generic.go:283 +0x815
12月 25 16:02:37 daocloud kubelet[22154]: k8s.io/apimachinery/pkg/util/wait.BackoffUntil.func1(0x30?)
12月 25 16:02:37 daocloud kubelet[22154]:         vendor/k8s.io/apimachinery/pkg/util/wait/backoff.go:226 +0x33
12月 25 16:02:37 daocloud kubelet[22154]: k8s.io/apimachinery/pkg/util/wait.BackoffUntil(0x0?, {0x4c0f620, 0xc000fd5b90}, 0x1, 0xc00020cfc0)
12月 25 16:02:37 daocloud kubelet[22154]:         vendor/k8s.io/apimachinery/pkg/util/wait/backoff.go:227 +0xaf
12月 25 16:02:37 daocloud kubelet[22154]: k8s.io/apimachinery/pkg/util/wait.JitterUntil(0xc000095fb0?, 0x45d964b800, 0x0, 0x0?, 0x4475bc?)
12月 25 16:02:37 daocloud kubelet[22154]:         vendor/k8s.io/apimachinery/pkg/util/wait/backoff.go:204 +0x7f
12月 25 16:02:37 daocloud kubelet[22154]: k8s.io/apimachinery/pkg/util/wait.Until(0xa946c5?, 0xa8f505?, 0xc000b11390?)
12月 25 16:02:37 daocloud kubelet[22154]:         vendor/k8s.io/apimachinery/pkg/util/wait/backoff.go:161 +0x1e
12月 25 16:02:37 daocloud kubelet[22154]: created by k8s.io/kubernetes/pkg/kubelet/pleg.(*GenericPLEG).Start in goroutine 234
12月 25 16:02:37 daocloud systemd[1]: kubelet.service: Main process exited, code=exited, status=2/INVALIDARGUMENT
12月 25 16:02:37 daocloud kubelet[22154]:         pkg/kubelet/pleg/generic.go:146 +0x185
12月 25 16:02:37 daocloud systemd[1]: kubelet.service: Unit entered failed state.
12月 25 16:02:37 daocloud systemd[1]: kubelet.service: Failed with result 'exit-code'.

Which issue(s) this PR fixes:

Fixes None

Special notes for your reviewer:

Does this PR introduce a user-facing change?

fix panic of Evented PLEG during kubelet start-up

[pacoxu]

I may add a e2e test later.

[pacoxu]

/cc @harche @swghosh

I find this issue when I run a daemonset on node and restart the kubelet which already turning on EventedPLEG with v1.29.0.

• I need to confirm the reproduce steps.

[k8s-ci-robot]

@pacoxu: GitHub didn't allow me to request PR reviews from the following users: swghosh.

Note that only kubernetes members and repo collaborators can review this PR, and authors cannot review their own PRs.

In response to this:

/cc harche swghosh

I find this issue when I run a daemonset on node and restart the kubelet which already turning on EventedPLEG with v1.29.0.

• I need to confirm the reproduce steps.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[bart0sh]

/triage accepted
/priority important-soon
/lgtm

/assign @mrunalp @derekwaynecarr @dchen1107
for a final approval

[k8s-ci-robot]

LGTM label has been added.

Git tree hash: 5b8e436f7562bae8f554e7708788bd4821272287

[kannon92]

Code looks good. Could you add a unit test for this?

[harche]

/lgtm

[dims]

one liner with a defensive nil check before using a pointer

/approve
/lgtm

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: dims, pacoxu

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