BenchmarkExportConntrackConns panics

[antoninbas]

Describe the bug
BenchmarkExportConntrackConns is panicking after merging #2854.

2021-11-04T22:34:25.4378372Z I1104 22:34:25.437109    1669 main.go:108] "Parse result" parseSet=map[BenchmarkPoll-2:[BenchmarkPoll-2 679 16542213.00 ns/op 1371489 B/op 53375 allocs/op]]
2021-11-04T22:34:28.2056529Z I1104 22:34:28.199618    1669 main.go:266] "Exec command output" out="goos: linux\ngoarch: amd64\npkg: antrea.io/antrea/pkg/agent/flowexporter/exporter\ncpu: Intel(R) Xeon(R) Platinum 8171M CPU @ 2.60GHz\nBenchmarkExportConntrackConns\npanic: runtime error: invalid memory address or nil pointer dereference [recovered]\n\tpanic: runtime error: invalid memory address or nil pointer dereference\n[signal SIGSEGV: segmentation violation code=0x1 addr=0x30 pc=0x13405ff]\n\ngoroutine 8 [running]:\ngithub.com/golang/mock/gomock.(*Controller).finish(0xc0004be300, 0x0, {0x148af60, 0x242cd00})\n\t/home/runner/go/pkg/mod/github.com/golang/mock@v1.6.0/gomock/controller.go:288 +0x30a\ngithub.com/golang/mock/gomock.(*Controller).Finish(0x0)\n\t/home/runner/go/pkg/mod/github.com/golang/mock@v1.6.0/gomock/controller.go:269 +0x38\npanic({0x148af60, 0x242cd00})\n\t/opt/hostedtoolcache/go/1.17.2/x64/src/runtime/panic.go:1038 +0x215\nantrea.io/antrea/pkg/agent/config.IsIPv4Enabled(...)\n\t/home/runner/work/antrea/antrea/pkg/agent/config/node_config.go:158\nantrea.io/antrea/pkg/agent/flowexporter/exporter.NewFlowExporter({0x0, 0x0}, {0x0, 0x0}, {0x0, 0x0}, 0x0, 0x0, 0x0, 0x0, ...)\n\t/home/runner/work/antrea/antrea/pkg/agent/flowexporter/exporter/exporter.go:165 +0xff\nantrea.io/antrea/pkg/agent/flowexporter/exporter.setupExporter(0x1)\n\t/home/runner/work/antrea/antrea/pkg/agent/flowexporter/exporter/exporter_perf_test.go:163 +0x157\nantrea.io/antrea/pkg/agent/flowexporter/exporter.BenchmarkExportConntrackConns(0xc000126480)\n\t/home/runner/work/antrea/antrea/pkg/agent/flowexporter/exporter/exporter_perf_test.go:85 +0x99\ntesting.(*B).runN(0xc000126480, 0x1)\n\t/opt/hostedtoolcache/go/1.17.2/x64/src/testing/benchmark.go:192 +0x126\ntesting.(*B).run1.func1()\n\t/opt/hostedtoolcache/go/1.17.2/x64/src/testing/benchmark.go:232 +0x59\ncreated by testing.(*B).run1\n\t/opt/hostedtoolcache/go/1.17.2/x64/src/testing/benchmark.go:225 +0xa5\nexit status 2\nFAIL\tantrea.io/antrea/pkg/agent/flowexporter/exporter\t0.035s\nFAIL\n"
2021-11-04T22:34:28.2065996Z I1104 22:34:28.199644    1669 main.go:267] "Exec command error" err=""
2021-11-04T22:34:28.2067237Z I1104 22:34:28.199683    1669 main.go:108] "Parse result" parseSet=map[]
2021-11-04T22:34:28.3533754Z F1104 22:34:28.352983    1669 main.go:60] failed to run a benchmark: failed to run '/opt/hostedtoolcache/go/1.17.2/x64/bin/go test -run '^$' -bench BenchmarkExportConntrackConns -benchtime 10x -timeout 10m -cpu 2 -v -benchmem ./pkg/agent/flowexporter/exporter' command: exit status 1
2021-11-04T22:34:28.3536726Z goroutine 1 [running]:
2021-11-04T22:34:28.3538014Z k8s.io/klog/v2.stacks(0x1)
2021-11-04T22:34:28.3539456Z 	/home/runner/go/pkg/mod/k8s.io/klog/v2@v2.20.0/klog.go:1038 +0x8a
2021-11-04T22:34:28.3540892Z k8s.io/klog/v2.(*loggingT).output(0x85eaa0, 0x3, 0x0, 0xc0000cc070, 0x1, {0x71961e, 0x10}, 0xc00015a400, 0x0)
2021-11-04T22:34:28.3542389Z 	/home/runner/go/pkg/mod/k8s.io/klog/v2@v2.20.0/klog.go:987 +0x7bd
2021-11-04T22:34:28.3543815Z k8s.io/klog/v2.(*loggingT).printDepth(0xc0000a4120, 0x8e160, 0x0, {0x0, 0x0}, 0x60, {0xc0007e6020, 0x1, 0x1})
2021-11-04T22:34:28.3545316Z 	/home/runner/go/pkg/mod/k8s.io/klog/v2@v2.20.0/klog.go:735 +0x1ae
2021-11-04T22:34:28.3546405Z k8s.io/klog/v2.(*loggingT).print(...)
2021-11-04T22:34:28.3547640Z 	/home/runner/go/pkg/mod/k8s.io/klog/v2@v2.20.0/klog.go:717
2021-11-04T22:34:28.3548615Z k8s.io/klog/v2.Fatal(...)
2021-11-04T22:34:28.3549712Z 	/home/runner/go/pkg/mod/k8s.io/klog/v2@v2.20.0/klog.go:1512
2021-11-04T22:34:28.3551007Z main.main()
2021-11-04T22:34:28.3552545Z 	/home/runner/work/benchci/benchci/main.go:60 +0xe5
2021-11-04T22:34:28.3553280Z 
2021-11-04T22:34:28.3554062Z goroutine 18 [chan receive]:
2021-11-04T22:34:28.3555088Z k8s.io/klog/v2.(*loggingT).flushDaemon(0x0)
2021-11-04T22:34:28.3556360Z 	/home/runner/go/pkg/mod/k8s.io/klog/v2@v2.20.0/klog.go:1181 +0x6a
2021-11-04T22:34:28.3557493Z created by k8s.io/klog/v2.init.0
2021-11-04T22:34:28.3558674Z 	/home/runner/go/pkg/mod/k8s.io/klog/v2@v2.20.0/klog.go:420 +0xfb

This is causing the Go Benchmark Test workflow to fail on the main branch.

[antoninbas]

@heanlan could you take a look at this?

@wenqiq we should probably run the benchmarks once for each PR (without bench-ci) to make sure that they are not broken, without consuming too many Github Actions minutes. What do you think?

[heanlan]

@heanlan could you take a look at this?

I'll look into it.

[wenqiq]

@wenqiq we should probably run the benchmarks once for each PR (without bench-ci) to make sure that they are not broken, without consuming too many Github Actions minutes. What do you think?

The Go benchmark test workflow has recorded the benchmark error of #2854 : https://github.com/antrea-io/antrea/actions/runs/1423364727

We can avoid this if we run the Go benchmark workflow for each PR, it will take about 17minutes which run the benchmarks twice. I think we can add a step in go.yaml to run the benchmarks, it will only take about 9-10minutes.

[antoninbas]

@wenqiq 10 minutes is still pretty large when run every time the PR is updated.
If something likes go test -run=XXX -bench=. -benchtime=1x performs the same job (without the possibility of flakes) and does it much faster, then we should consider doing that instead.