PMM-1901 metrics endpoint and collectors filtering.

[idexter]

No description provided.

[CLAassistant]

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[codecov]

Codecov Report

Merging #23 into master will decrease coverage by 0.45%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master      #23      +/-   ##
==========================================
- Coverage   83.71%   83.26%   -0.46%     
==========================================
  Files           9        9              
  Lines         694      699       +5     
==========================================
+ Hits          581      582       +1     
- Misses        100      103       +3     
- Partials       13       14       +1

Impacted Files	Coverage Δ
basic/basic.go	100% <100%> (ø)	⬆️
client/transport.go	87.5% <0%> (-12.5%)	⬇️

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[rnovikovP]

@dexterHD pls click CLA button

[idexter]

@AlekSi Please, check this out when you have a time. It's waiting for 2 weeks.

[AlekSi]

rds_exporter is not used by PMM 2.0 beta6, so it is not a priority.

That being said, if you want to do something about this PR, please think how to simplify factory.go. Code there looks overcomplicated for an apparently simple task.

[idexter]

@rnovikovP @AlekSi But it's in PMM 2.0 beta6 release in JIRA 😕 As about complicated code, it's because of backward compatibility with the old endpoints. I'm not sure it worth to do something about that in the meaning of priorities.