antctl.exe supportbundle command doesn't support path flag on Windows

[XinShuYang]

Describe the bug
In Windows, running antctl.exe supportbundle -d reports an error. The antctl tool is expected to support the -d (path) flag according to https://github.com/antrea-io/antrea/blob/main/docs/antctl.md#collecting-support-information, but it is not working on Windows.

To Reproduce

1. Run the following command in Windows:

.\antctl.exe supportbundle -d C:\var\log\antrea\

2. The following error is observed:

Error: unknown shorthand flag: 'd' in -d

Expected
The command should allow the user to specify a path to save the support bundle file on Windows using the -d flag.

Actual behavior
An error is thrown when trying to use the -d flag in Windows:
Error: unknown shorthand flag: 'd' in -d

Versions:
Antrea V2.1

[XinShuYang]

Hi @luolanzone @rajnkamr, recently @wenyingd and I found two bugs with antctl on Windows(#6688 #6687). While they are not urgent, we believe they should be addressed eventually. Please feel free to assign them to anyone interested or needing familiarity with the antrea Windows/antctl modules. Thanks!

[XinShuYang]

After investigation, I found supportbundle -d flag is only available outside pod in the controller mode.

antrea/pkg/antctl/raw/supportbundle/command.go

Line 109 in 18e9111

} else if runtime.Mode == runtime.ModeController && !runtime.InPod {

. When this command is run in the pod, the -d flag is not supported, and the file is saved to a fixed path.

antrea/pkg/antctl/raw/supportbundle/command.go

Line 160 in 18e9111

fmt.Fprintf(writer, "Created bundle under %s\n", os.TempDir())

On Windows, there is a slight difference. The reason why antctl supportbundle -d may still fail on a remote node is that if the server API token exists at the Windows path C:\var\run\antrea\apiserver, the current implementation sets InPod and agent mode to true. As the result, antctl supportbundle always saves the file to the fixed path in this mode.

antrea/pkg/antctl/runtime/runtime.go

Lines 61 to 67 in 18e9111

	if runtime.IsWindowsPlatform() && !InPod {
	if _, err := os.Stat(apis.APIServerLoopbackTokenPath); err == nil {
	InPod = true
	Mode = ModeAgent
	return
	}
	}

Perhaps we can discuss potential changes to the documentation to prevent misunderstandings. cc @luolanzone @wenyingd