Support listen on vsock

[jeffrey4l]

metrics can be retrive without nic between host and qemu guest through vsock.

more info check

• https://man7.org/linux/man-pages/man7/vsock.7.html
• https://wiki.qemu.org/Features/VirtioVsock

[SuperQ]

Interesting idea. This also needs to be added to the Go documentation and probably the flag help string in web/kingpinflag/flag.go.

[SuperQ]

Please add documentation to the ListenAndServe func docs (before like 285). A link to https://wiki.qemu.org/Features/VirtioVsock would be useful there.

[SuperQ]

Thanks, looks good.

[bwplotka]

👍🏽

[SuperQ]

Would you please rebase to fix the conflict?

[jesusvazquez]

LGTM

I'd like some testing for ListenAndServe here

exporter-toolkit/web/tls_config_test.go

Lines 479 to 492 in 48431d7

	go func() {
	defer func() {
	if recover() != nil {
	recordConnectionError(errors.New("Panic starting server"))
	}
	}()
	flags := FlagConfig{
	WebListenAddresses: &([]string{port}),
	WebSystemdSocket: OfBool(false),
	WebConfigFile: &test.YAMLConfigPath,
	}
	err := ListenAndServe(server, &flags, testlogger)
	recordConnectionError(err)
	}()

To make sure it listens both on tcp and vsock if specified.

But I won't block on this if other people don't think this is necessary 👍

[Leonid99]

Shouldn't this be return err? It silently swallows an error condition.

[Leonid99]

Would you please rebase to fix the conflict?

For your consideration, I rebased this branch as #220 to allow it to be merged (with original authorship of @jeffrey4l). The only conflict is go.mod.