panic: send on closed channel when issuing CTRL-C while connectivity tests are running on EKS

[christarazi]

General Information

• Cilium CLI version (run cilium version)

cilium-cli: v0.16.15-3-g1ef635612 compiled with go1.22.1 on linux/amd64
cilium image (default): v1.16.0
cilium image (stable): v1.16.1
cilium image (running): 1.15.8

• Platform / infrastructure information (e.g. AWS / Azure / GCP, image / kernel versions)
  AWS

[=] [cilium-test-1] Test [client-ingress-from-other-client-icmp-deny] [34/86]
............
^CCancellation request (context canceled) received, cancelling tests...
panic: send on closed channel

goroutine 13879 [running]:
github.com/cilium/cilium-cli/connectivity/check.(*ConcurrentLogger).FinishTest(0xc00092eb40, 0xc001470f20)
        /home/chris/code/cilium/cilium-cli/connectivity/check/logger.go:95 +0x18c
github.com/cilium/cilium-cli/connectivity/check.(*ConnectivityTest).Run.func1.1()
        /home/chris/code/cilium/cilium-cli/connectivity/check/context.go:394 +0x2b
github.com/cilium/cilium-cli/connectivity/check.(*ConnectivityTest).Run.func1()
        /home/chris/code/cilium/cilium-cli/connectivity/check/context.go:406 +0x2b3
created by github.com/cilium/cilium-cli/connectivity/check.(*ConnectivityTest).Run in goroutine 762
        /home/chris/code/cilium/cilium-cli/connectivity/check/context.go:392 +0x91

[ldlb9527]

func (c *ConcurrentLogger) FinishTest(test *Test) {
	//...
	c.messageCh <- message{
		namespace: test.Context().Params().TestNamespace,
		testName:  test.Name(),
		data:      buf.String(),
		finish:    true,
	}
}

Panic occurs in the FinishTest function,the reason is due to the following code:

		ctx, _ := signal.NotifyContext(cmd.Context(), os.Interrupt, syscall.SIGTERM)

		if params.Timeout > 0 {
			timeoutCtx, cancelFunc := context.WithTimeoutCause(ctx, params.Timeout, fmt.Errorf("connectivity test suite timeout (%s) reached", params.Timeout))
			defer cancelFunc()
			ctx = timeoutCtx
		}

		go func() {
			<-ctx.Done()
			connTests[0].Logf("Cancellation request (%s) received, cancelling tests...", context.Cause(ctx))
		}()

		logger.Start(ctx)
		defer logger.Stop()
		return connectivity.Run(ctx, connTests, hooks)

Receiving an interrupt signal will result in logger.Start(ctx) execute close(messageCh),and then a panic occurs

The code might still have an issue where the logger.Stop() function could attempt to execute close(messageCh) a second time, leading to a panic.