kubernetes processor use correct os path separator

[exekias]

This PR completes #9205 to support windows nodes (and log paths) when adding kubernetes metadata

Original author: @zentron
closes #9196

[odacremolbap]

a couple, very opinionated glitches

other than that, LGTM

[odacremolbap]

Not necesarily part of this review, but probably something to discuss:
Tests are kinda innovative, I would expect more table like and would dare to say that's the case for anyone hitting this piece of code.

beats/filebeat/processor/add_kubernetes_metadata/matchers_test.go

Line 124 in 5a8c137

func executeTestWithResourceType(t *testing.T, cfgLogsPath string, cfgResourceType string, source string, expectedResult string) {

[odacremolbap]

Not necesarily part of this review, but probably something to discuss:

I don't think there might be many kubelets running at locations others than default at linux, but could happen.
Windows is a different story, by default C: is where the OS lies, some admins choose a different location for any App that runs on it. We can't take for granted C:

We to add these locations to the config file, and provide current values as defaults

[exekias]

tbh, I agree this whole code needs a refactor to better handle the different use cases (docker, kubernetes, OS)..., will put some time on improve it 👍

[kaiyan-sheng]

We to add these locations to the config file, and provide current values as defaults

I like the idea of adding default log path, pod logs path and container logs path into config. If they are missing from config, then use the default in the code 😄

[kaiyan-sheng]

Looks good, besides the changelog conflict 👍

[exekias]

merging this now, we can revisit this code later, I think it needs a broader refactor