add push-labels option for java sdk and add --custom-lables option for mount

[reAsOn2010]

close #4245

Does some defensive programming (check the format of parameter) needed ?

[CLAassistant]

All committers have signed the CLA.

[codecov]

Codecov Report

Attention: 10 lines in your changes are missing coverage. Please review.

Comparison is base (d1dcd95) 55.81% compared to head (2d2ec59) 55.78%.
Report is 6 commits behind head on main.

Files	Patch %	Lines
cmd/mount.go	55.00%	6 Missing and 3 partials ⚠️
cmd/mdtest.go	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4312      +/-   ##
==========================================
- Coverage   55.81%   55.78%   -0.04%     
==========================================
  Files         153      153              
  Lines       39631    39654      +23     
==========================================
- Hits        22122    22120       -2     
- Misses      15030    15053      +23     
- Partials     2479     2481       +2     

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[zhijian-pro]

Does some defensive programming (check the format of parameter) needed ?

Yes

[zhijian-pro]

The above code can only solve the problem of java sdk custom lable, go process also need to be added.
If you are interested, you can improve the section.

juicefs/cmd/mount.go

Line 162 in 6ef6813

func wrapRegister(mp, name string) (prometheus.Registerer, *prometheus.Registry) {

[reAsOn2010]

OK, I searched the code base with pattern "push-gateway" then I only find the code in java sdk. I'll dive into the golang process code.

[zhijian-pro]

The previous issue was a special case, and we should support --custom-lables, whether push (push-gateway) or pull (prometheus).

[reAsOn2010]

Is this PR causing test failure?

[zhijian-pro]

It doesn't matter if mutate-test doesn't pass.

[zhijian-pro]

LGTM!