Error logs in agent: Unable to cancel request for *exec.roundTripper

[anfernee]

Describe the bug
antrea-agent on windows (only observed in windows, but it should be platform independent) shows a lot of error logs saying Unable to cancel request for *exec.roundTripper. It's pretty annoying, though the functionality seems not impacted. The DEBUG logs are like the following.

I0318 22:25:03.370898    9568 config.go:168] Calling handler.OnEndpointsUpdate
I0318 22:25:03.370898    9568 config.go:168] Calling handler.OnEndpointsUpdate
W0318 22:25:03.884876    9568 transport.go:260] Unable to cancel request for *exec.roundTripper
I0318 22:25:03.884876    9568 streamwatcher.go:114] Unable to decode an event from the watch stream: net/http: request canceled (Client.Timeout or context cancellation while reading body)
I0318 22:25:03.884876    9568 reflector.go:530] pkg/mod/k8s.io/client-go@v0.21.0/tools/cache/reflector.go:167: Watch close - *v1.ConfigMap total 0 items received
W0318 22:25:04.581472    9568 transport.go:260] Unable to cancel request for *exec.roundTripper
I0318 22:25:04.581472    9568 streamwatcher.go:114] Unable to decode an event from the watch stream: net/http: request canceled (Client.Timeout or context cancellation while reading body)
I0318 22:25:04.581472    9568 reflector.go:530] pkg/mod/k8s.io/client-go@v0.21.0/tools/cache/reflector.go:167: Watch close - *v1.ConfigMap total 0 items received
I0318 22:25:04.608774    9568 net_windows.go:332] IP configuration for interface antrea-gw0 does not need to change
I0318 22:25:05.377107    9568 config.go:168] Calling handler.OnEndpointsUpdate
I0318 22:25:05.377107    9568 config.go:168] Calling handler.OnEndpointsUpdate

To Reproduce
Run the agent and check the log.

Expected
No error logs

Actual behavior
There are error logs.

Versions:
Please provide the following information:

• Antrea version (Docker image tag). v1.2.0
• Kubernetes version (use kubectl version). If your Kubernetes components have different versions, please provide the version for all of them. v1.22.4
• Container runtime: which runtime are you using (e.g. containerd, cri-o, docker) and which version are you using? containerd and docker
• Linux kernel version on the Kubernetes Nodes (uname -r). n/a
• If you chose to compile the Open vSwitch kernel module manually instead of using the kernel module built into the Linux kernel, which version of the OVS kernel module are you using? Include the output of modinfo openvswitch for the Kubernetes Nodes. n/a

[anfernee]

cc @shettyg

[antoninbas]

I did some research into this.
This is specific to users of client-go credential plugins, and in this case the exec auth plugin. @anfernee I assume that you are indeed using this plugin for client-go authentication and that you configured this plugin in the kubeconfig used by the antrea-agent?

This issue doesn't impact functionality and it was fixed in K8s v1.23: kubernetes/kubernetes#106014. The fix wasn't backported to earlier versions, so this issue will be resolved when we upgrade the client-go dependency in Antrea to v0.23 (we currently use v0.21.2).

Given that there is an open feature request (#3540) which requires us to update to client-go v0.24, and given that updating the client-go version can be a bit of a pain, I suggest that we tackle both of these at the same time, when K8s v1.24 is GA at the end of the month.

[anfernee]

Thanks @antoninbas for the updates. Yes, you are right. We do use exec auth plugin for both kubelet and antrea-agent in GKE, so very likely to be the issue you described.