[receiver/nopreceiver] Add the nopreceiver

[evan-bradley]

Description:

Add the nopreceiver. This can be helpful if a user wants to start the Collector with a dummy pipeline to only enable extensions. It could also be used to start a dynamically-configured Collector that starts with no config and waits to receive its config from a confmap.Provider that supports reloads.

Link to tracking Issue:

Works toward #7316

Testing:

Added lifecycle tests; the receiver doesn't do anything.

Documentation:

Added a readme for the component.

[evan-bradley]

cc @djaglowski @tigrannajaryan

[codecov]

Codecov Report

Attention: Patch coverage is 73.33333% with 4 lines in your changes are missing coverage. Please review.

Project coverage is 90.93%. Comparing base (2413346) to head (e4c3692).

Files	Patch %	Lines
.../nopreceiver/internal/metadata/generated_status.go	0.00%	4 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #9446      +/-   ##
==========================================
- Coverage   90.95%   90.93%   -0.02%     
==========================================
  Files         350      352       +2     
  Lines       18576    18591      +15     
==========================================
+ Hits        16895    16906      +11     
- Misses       1354     1358       +4     
  Partials      327      327              

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[djaglowski]

LGTM, minor CI issues aside

[evan-bradley]

Codecov was complaining that I wasn't testing the generated Meter or Tracer functions. I already had to manually edit the file to satisfy make goimpi, so I just removed them. If we want to take another approach to this I'm open to suggestions. I could test these or even try to use them in the code if we wanted.

Edit: this fails another check, I had to change my approach. See below.

[evan-bradley]

It looks like I need to leave in the Meter and Tracer functions. Is the codecov check required to pass to merge this? None of the other components appear to test these and I'd prefer not to write tests just to increase code coverage.

[andrzej-stencel]

Love it! ❤️

[codeboten]

@evan-bradley ptal at the check failure

[evan-bradley]

@codeboten should be good now, thanks. The codecov check is still failing due to a lack of test coverage on generated code, but it looks like that's an optional check.

[dmitryax]

LGTM. Please rebase and update the dependancies

[evan-bradley]

@dmitryax Thanks for taking a look. Should be good to go now.

[evan-bradley]

@dmitryax CI is green now, minus the code coverage failure due to the lack of tests for generated code.