Antrea antctl get ovsflows response INTERNAL_ERROR

[wenqiq]

Describe the bug

get ovsflows:

antctl get ovsflows -N 355cf6bb-973e-4969-a39e-2db0a6acf405 -n antrea-scale-test-ns
Error: Get “https://127.0.0.1:10350/ovsflows?namespace=antrea-scale-test-ns&networkpolicy=355cf6bb-973e-4969-a39e-2db0a6acf405”: stream error: stream ID 1; INTERNAL_ERROR

agent logs:

E1028 12:21:40.015378       1 runtime.go:76] Observed a panic: runtime error: invalid memory address or nil pointer dereference
goroutine 566296 [running]:
k8s.io/apiserver/pkg/server/filters.(*timeoutHandler).ServeHTTP.func1.1(0xc001e56540)
        /tmp/gopath/pkg/mod/k8s.io/apiserver@v0.21.0/pkg/server/filters/timeout.go:102 +0x113
panic(0x2332f60, 0x3a00a50)
        /usr/local/go/src/runtime/panic.go:969 +0x175
antrea.io/antrea/pkg/agent/openflow.(*client).GetNetworkPolicyFlowKeys(0xc00069c700, 0xc001e56397, 0x24, 0xc001e56374, 0x14, 0x0, 0x0, 0x0)
        /usr/src/antrea.io/antrea/pkg/agent/openflow/network_policy.go:1439 +0x137
antrea.io/antrea/pkg/agent/apiserver/handlers/ovsflows.getNetworkPolicyFlows(0x29def80, 0xc00089e680, 0xc001e56397, 0x24, 0xc001e56374, 0x14, 0x0, 0x0, 0x203000, 0x203000, ...)
        /usr/src/antrea.io/antrea/pkg/agent/apiserver/handlers/ovsflows/handler.go:178 +0x14f
antrea.io/antrea/pkg/agent/apiserver/handlers/ovsflows.HandleFunc.func1(0x7f6f986efeb0, 0xc00bb70378, 0xc00d1c2700)
        /usr/src/antrea.io/antrea/pkg/agent/apiserver/handlers/ovsflows/handler.go:211 +0x697
net/http.HandlerFunc.ServeHTTP(0xc002b34360, 0x7f6f986efeb0, 0xc00bb70378, 0xc00d1c2700)
        /usr/local/go/src/net/http/server.go:2042 +0x44
k8s.io/apiserver/pkg/server/mux.(*pathHandler).ServeHTTP(0xc002289f80, 0x7f6f986efeb0, 0xc00bb70378, 0xc00d1c2700)
        /tmp/gopath/pkg/mod/k8s.io/apiserver@v0.21.0/pkg/server/mux/pathrecorder.go:241 +0x6fa
k8s.io/apiserver/pkg/server/mux.(*PathRecorderMux).ServeHTTP(0xc00187e070, 0x7f6f986efeb0, 0xc00bb70378, 0xc00d1c2700)
        /tmp/gopath/pkg/mod/k8s.io/apiserver@v0.21.0/pkg/server/mux/pathrecorder.go:234 +0x8c
k8s.io/apiserver/pkg/server.director.ServeHTTP(0x269b917, 0x10, 0xc002ade6c0, 0xc00187e070, 0x7f6f986efeb0, 0xc00bb70378, 0xc00d1c2700)
        /tmp/gopath/pkg/mod/k8s.io/apiserver@v0.21.0/pkg/server/handler.go:154 +0x87f
k8s.io/apiserver/pkg/endpoints/filterlatency.trackCompleted.func1(0x7f6f986efeb0, 0xc00bb70378, 0xc00d1c2700)
        /tmp/gopath/pkg/mod/k8s.io/apiserver@v0.21.0/pkg/endpoints/filterlatency/filterlatency.go:95 +0x193
net/http.HandlerFunc.ServeHTTP(0xc002aaaba0, 0x7f6f986efeb0, 0xc00bb70378, 0xc00d1c2700)
        /usr/local/go/src/net/http/server.go:2042 +0x44
k8s.io/apiserver/pkg/endpoints/filters.WithAuthorization.func1(0x7f6f986efeb0, 0xc00bb70378, 0xc00d1c2700)
        /tmp/gopath/pkg/mod/k8s.io/apiserver@v0.21.0/pkg/endpoints/filters/authorization.go:64 +0x5ba
...

To Reproduce

create large scale networkPolicies(about 5k), and use antctl to get ovsflows

Expected

antctl get ovsflows works well with large scale pods and networkPolicies

Actual behavior

antctl get ovsflows reponse INTERNAL_ERROR, observed a panic in agent log: runtime error: invalid memory address or nil pointer ...

Versions:

• Antrea version
  1.2.2

• Kubernetes version

kubectl version
Client Version: version.Info{Major:"1", Minor:"21", GitVersion:"v0.21.0-beta.1", GitCommit:"1077b0516d5baf6f2717e4cb34f58236c0fb7a8c", GitTreeState:"clean", BuildDate:"2021-07-23T18:52:05Z", GoVersion:"go1.16.4", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"20", GitVersion:"v1.20.0+c8905da", GitCommit:"c8905da1d144e4625c8355643d8c034692accdcd", GitTreeState:"clean", BuildDate:"2021-04-07T09:12:37Z", GoVersion:"go1.15.7", Compiler:"gc", Platform:"linux/amd64"}
WARNING: version difference between client (0.21) and server (1.20) exceeds the supported minor version skew of +/-1

• Container runtime
  cri-o
• Linux kernel version on the Kubernetes Nodes

 uname -r
4.18.0-240.22.1.el8_3.x86_64

Additional context

[github-actions]

This issue is stale because it has been open 90 days with no activity. Remove stale label or comment, or this will be closed in 90 days

[tnqn]

Fixed by #3335