Data mover micro-service watcher

[Lyndon-Li]

Fix #7932. Data mover micro-service watcher according to design #7576

[codecov]

Codecov Report

Attention: Patch coverage is 67.96117% with 99 lines in your changes missing coverage. Please review.

Project coverage is 58.88%. Comparing base (6a3e226) to head (faa704d).
Report is 35 commits behind head on main.

Files	Patch %	Lines
pkg/datapath/micro_service_watcher.go	59.34%	87 Missing ⚠️
pkg/util/logging/log_merge_hook.go	89.74%	3 Missing and 1 partial ⚠️
pkg/cmd/cli/nodeagent/server.go	0.00%	3 Missing ⚠️
pkg/util/kube/pod.go	91.89%	3 Missing ⚠️
pkg/util/logging/default_logger.go	75.00%	1 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #7999      +/-   ##
==========================================
+ Coverage   58.82%   58.88%   +0.06%     
==========================================
  Files         346      351       +5     
  Lines       28891    29367     +476     
==========================================
+ Hits        16996    17294     +298     
- Misses      10463    10639     +176     
- Partials     1432     1434       +2     

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[kaovilai]

I think re-titling ms to microservice would be less confusing.

[Lyndon-Li]

I think re-titling ms to microservice would be less confusing.

Done

[shubham-pampattiwar]

Shouldn't we use ms.Close() here ? Are we not missing the cancel() call as well ?

[Lyndon-Li]

I am not so confident to call ms.Close() in the Init, as ms.Close() is doing more things and may do even more in future, if it is not required, we should not couple them together.
So here I moved ms.ctx, ms.cancel = context.WithCancel(ctx) to the end, actually, this ctx with cancel is used after Init.

[Lyndon-Li]

Actually, the caller may also call ms.Close() when Init returns error. At present, there is no problem.
But here I think we should avoid adding one more coupling if we can, in future, if ms.Close() is not suitable to be called when Init returns error, we should correct the caller.

[shubham-pampattiwar]

Shouldn't we use ms.Close() here ? Are we not missing the cancel() call as well ?
same as line 148 comment earlier. Curious to know if my understanding is incorrect.

[shubham-pampattiwar]

or do we need to combine both the defer calls for podhandler and eventhandler and then call ms.Close()

[Lyndon-Li]

See #7999 (comment)

[Lyndon-Li]

@shubham-pampattiwar @sseago @blackpiglet I changed the code slightly per discussion #7999 (comment), please have another look. Thanks.