feat(exporter-logs-otlp-grpc): implements otlp-grpc exporters for logs

[llc1123]

Which problem is this PR solving?

• otlp-transformer for log records.
• exporter-logs-otlp-grpc

Short description of the changes

• Added transformer for log records.
• Cleaned up some unused code.
• Improved test coverage of otlp-transformer.
• Added new package exporter-logs-otlp-grpc

Type of change

Please delete options that are not relevant.

• New feature (non-breaking change which adds functionality)
• This change requires a documentation update

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide instructions so we can reproduce. Please also list any relevant details for your test configuration

• Run the included unit tests.

Checklist:

• Followed the style guidelines of this project
• Unit tests have been added
• Documentation has been updated

[vinniimiranda]

Hi, thanks for your effort on thi PR, there is any prediction or deadline for this to be merged?

Thanks in advance.

[llc1123]

Hi, thanks for your effort on thi PR, there is any prediction or deadline for this to be merged?

Thanks in advance.

That depends on #3549.

[codecov]

Codecov Report

Merging #3712 (552f5b3) into main (9347ca6) will increase coverage by 0.12%.
The diff coverage is 93.26%.

❗ Current head 552f5b3 differs from pull request most recent head 11346f9. Consider uploading reports for the commit 11346f9 to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3712      +/-   ##
==========================================
+ Coverage   93.39%   93.52%   +0.12%     
==========================================
  Files         290      293       +3     
  Lines        8863     8941      +78     
  Branches     1838     1849      +11     
==========================================
+ Hits         8278     8362      +84     
+ Misses        585      579       -6     

Impacted Files	Coverage Δ
...ckages/opentelemetry-core/src/utils/environment.ts	92.53% <ø> (ø)
...ental/packages/otlp-grpc-exporter-base/src/util.ts	75.96% <30.00%> (-3.54%)	⬇️
...es/exporter-logs-otlp-grpc/src/OTLPLogsExporter.ts	100.00% <100.00%> (ø)
...ntal/packages/otlp-grpc-exporter-base/src/types.ts	100.00% <100.00%> (ø)
...l/packages/otlp-transformer/src/common/internal.ts	100.00% <100.00%> (+26.92%)	⬆️
...mental/packages/otlp-transformer/src/logs/index.ts	100.00% <100.00%> (ø)
...mental/packages/otlp-transformer/src/logs/types.ts	100.00% <100.00%> (ø)

... and 2 files with indirect coverage changes

[llc1123]

cc @dyladan @pichlermarc

[weyert]

I am still a bit confused about the purpose of Logs. Do I need to implement an exporter for winston, bunyan, pino etc? Or would I call logs-api in a custom transporter of these libraries and then create a logs exporter for the logs backend of choice e.g. Cloud Logging or Loki?

[llc1123]

I am still a bit confused about the purpose of Logs. Do I need to implement an exporter for winston, bunyan, pino etc? Or would I call logs-api in a custom transporter of these libraries and then create a logs exporter for the logs backend of choice e.g. Cloud Logging or Loki?

This is just another logging framework like bunyan/winston/pino, which supports different backends by exporters.

[martinkuba]

@weyert The Logs API is currently intended for building appenders for existing logging frameworks, so that they can be exported to OTLP backends. The API is NOT intended to be called directly in instrumentations or user code. This is why it's currently called "Bridge API".
https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/logs/bridge-api.md

[vinniimiranda]

Question, is this a http exporter as well?

[llc1123]

Question, is this a http exporter as well?

No, only gRPC.

[momenthana]

Question, is this a http exporter as well?

#3755 a draft of pre-work for this PR!