[otlp] Remove the Google.Protobuf / Grpc packages, and replace the logs and metrics with the new implementation

[rajkumar-rangaraj]

Fixes #5730
Design discussion issue #

Changes

Please provide a brief description of the changes here.

OpenTelemetry.Exporter.OpenTelemetryProtocol

• Replaced the current logs and metrics implementation with the new one. Deleted all existing implementations and renamed the new implementation to the existing names.
• Remove the following package references from the OTLP Exporter project
  • Google.Protobuf
  • Grpc
  • Grpc.Net.Client
  • Grpc.Tools
• Deleted all proto files from the project

Tests / Benchmarks

• Updated both tests and benchmarks project to include proto files and the following packages Google.Protobuf, Grpc, Grpc.Tools and Grpc.Net.Client.
• Updated the tests.

Merge requirement checklist

• CONTRIBUTING guidelines followed (license requirements, nullable enabled, static analysis, etc.)
• Unit tests added/updated
• Appropriate CHANGELOG.md files updated for non-trivial changes
• Changes in public API reviewed (if applicable)

[rajkumar-rangaraj]

Added a logical condition here to honor the existing behavior.

[CodeBlanch]

Curious how it got by tests before?

[rajkumar-rangaraj]

New implementation was never tested on it. On the replacement we caught this issue.

[rajkumar-rangaraj]

The actual issue was with the HTTP implementation. In the gRPC case, we append the path in all scenarios. However, for HTTP, the path is appended only if it is provided by default or through environment variables. If an endpoint is explicitly set, we do not append the path in the HTTP case, but this behavior was not being followed in new implementation.

During my initial implementation, I mistakenly assumed this was a bug and removed the check. However, there was an existing test case that validated this behavior.

exporterEndpoint = options.AppendSignalPathToEndpoint
                ? options.Endpoint.AppendPathIfNotPresent(signalPath)
                : options.Endpoint;

[codecov]

Codecov Report

Attention: Patch coverage is 73.80952% with 22 lines in your changes missing coverage. Please review.

Project coverage is 86.23%. Comparing base (84e6afb) to head (c54a555).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
....Exporter.OpenTelemetryProtocol/OtlpLogExporter.cs	56.00%	11 Missing ⚠️
...porter.OpenTelemetryProtocol/OtlpMetricExporter.cs	52.17%	11 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #6005      +/-   ##
==========================================
+ Coverage   85.15%   86.23%   +1.08%     
==========================================
  Files         272      257      -15     
  Lines       12420    11690     -730     
==========================================
- Hits        10576    10081     -495     
+ Misses       1844     1609     -235     

Flag	Coverage Δ
unittests-Project-Experimental	86.07% <73.80%> (+0.92%)	⬆️
unittests-Project-Stable	86.11% <73.80%> (+0.97%)	⬆️
unittests-Solution	86.13% <73.80%> (?)
unittests-UnstableCoreLibraries-Experimental	85.78% <ø> (?)

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
...ol/Implementation/ExportClient/OtlpExportClient.cs	100.00% <100.00%> (ø)
...mplementation/ExportClient/OtlpGrpcExportClient.cs	66.66% <ø> (ø)
...mplementation/ExportClient/OtlpHttpExportClient.cs	100.00% <ø> (ø)
...yProtocol/Implementation/ExportClient/OtlpRetry.cs	85.71% <100.00%> (+1.84%)	⬆️
...tlpExporterPersistentStorageTransmissionHandler.cs	92.72% <100.00%> (+57.94%)	⬆️
...ansmission/OtlpExporterRetryTransmissionHandler.cs	80.00% <100.00%> (+60.00%)	⬆️
...on/Transmission/OtlpExporterTransmissionHandler.cs	100.00% <100.00%> (+29.41%)	⬆️
...TelemetryProtocol/OtlpExporterOptionsExtensions.cs	96.90% <100.00%> (+8.37%)	⬆️
...lemetryProtocol/OtlpLogExporterHelperExtensions.cs	94.26% <100.00%> (+0.67%)	⬆️
...nTelemetryProtocol/OtlpMetricExporterExtensions.cs	96.51% <100.00%> (+1.05%)	⬆️
... and 3 more

... and 10 files with indirect coverage changes

[Kielek]

🎉 I do not have enough time to review it right now, but it is great to see this progress.

[TimothyMothra]

It looks like the proto files are copied into two directories, unit test & benchmarks.
Can these be stored in a common directory?

[CodeBlanch]

Dropping these dependencies is probably worthy of a CHANGELOG entry? What you think @alanwest?

[rajkumar-rangaraj]

This definitely needs to be a part of the changelog. There are few things we need to cover in the changelog, planning to cover as follow-up.

1. Removal of this packages
2. Breaking change on PeerServiceResolver, in one the earlier PR got feedback from you and Alan and we decided to remove this look up as we aren't aware why this logic was present https://github.com/open-telemetry/opentelemetry-dotnet/blob/84e6afbebae67f4e9b498f1702edfe4ceccf34ec/src/Shared/PeerServiceResolver.cs
3. Call-out on the internal serialization change.

[CodeBlanch]

LGTM