Add OTLP Metric Exporter Factory and OtlpGrpcClient

[owent]

Signed-off-by: owent admin@owent.net

Fixes #1603
Fixes #1605

Changes

• Add OtlpGrpcMetricExporterFactory and OtlpHttpMetricExporterFactory.
• Fix compatibility of OTLP log unit tests for MSVC.
• Add OtlpGrpcClient

For significant contributions please make sure you have completed the following items:

• CHANGELOG.md updated for non-trivial changes
• Unit tests have been added
• Changes in public API reviewed

[codecov]

Codecov Report

Merging #1606 (30e4586) into main (951768a) will decrease coverage by 0.07%.
The diff coverage is n/a.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1606      +/-   ##
==========================================
- Coverage   85.26%   85.20%   -0.06%     
==========================================
  Files         156      156              
  Lines        4978     4978              
==========================================
- Hits         4244     4241       -3     
- Misses        734      737       +3     

Impacted Files	Coverage Δ
ext/src/http/client/curl/http_client_curl.cc	80.31% <0.00%> (-1.13%)	⬇️

[lalitb]

@owent - you may want to fix the conflict from #1601 for this PR :)

[owent]

@owent - you may want to fix the conflict from #1601 for this PR :)

Done

[esigo]

LGTM
Thanks for the PR :)

[lalitb]

Did a quick validations on the binaries generated from this PR.

It seems that example_otlp_grpc_log still has dependency on both libopentelemetry_exporter_otlp_grpc.so and libopentelemetry_exporter_otlp_grpc_log.so. Should that be fixed?

$ ldd example_otlp_grpc_log
        linux-vdso.so.1 (0x00007fff86bf5000)
        libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f4b4ef1b000)
        libcommon_logs_foo_library.so => /tmp/owent/opentelemetry-cpp/build/examples/common/logs_foo_library/libcommon_logs_foo_library.so (0x00007f4b4eeb6000)
        libopentelemetry_exporter_otlp_grpc.so => /tmp/owent/opentelemetry-cpp/build/exporters/otlp/libopentelemetry_exporter_otlp_grpc.so (0x00007f4b4edff000)
        libopentelemetry_exporter_otlp_grpc_log.so => /tmp/owent/opentelemetry-cpp/build/exporters/otlp/libopentelemetry_exporter_otlp_grpc_log.so (0x00007f4b4ed48000)
        libopentelemetry_trace.so => /tmp/owent/opentelemetry-cpp/build/sdk/src/trace/libopentelemetry_trace.so (0x00007f4b4ec4a000)
        libopentelemetry_logs.so => /tmp/owent/opentelemetry-cpp/build/sdk/src/logs/libopentelemetry_logs.so (0x00007f4b4eb63000)
        libopentelemetry_exporter_otlp_grpc_client.so => /tmp/owent/opentelemetry-cpp/build/exporters/otlp/libopentelemetry_exporter_otlp_grpc_client.so (0x00007f4b4e5e2000)
        libstdc++.so.6 => /lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007f4b4e400000)
        libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007f4b4e3e5000)
        libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f4b4e1f3000)
        /lib64/ld-linux-x86-64.so.2 (0x00007f4b4f1d1000)
        libopentelemetry_otlp_recordable.so => /tmp/owent/opentelemetry-cpp/build/exporters/otlp/libopentelemetry_otlp_recordable.so (0x00007f4b4dec1000)
        libopentelemetry_common.so => /tmp/owent/opentelemetry-cpp/build/sdk/src/common/libopentelemetry_common.so (0x00007f4b4deae000)
        libopentelemetry_resources.so => /tmp/owent/opentelemetry-cpp/build/sdk/src/resource/libopentelemetry_resources.so (0x00007f4b4ddd1000)
        libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f4b4dc82000)
        libssl.so.1.1 => /lib/x86_64-linux-gnu/libssl.so.1.1 (0x00007f4b4dbef000)
        libcrypto.so.1.1 => /lib/x86_64-linux-gnu/libcrypto.so.1.1 (0x00007f4b4d917000)
        libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f4b4d911000)

While example_otlp_grpc is rightly dependent on only libopentelemetry_exporter_otlp_grpc.so.

$ ldd ./example_otlp_grpc
        linux-vdso.so.1 (0x00007fff1a3e1000)
        libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f6543907000)
        libcommon_foo_library.so => /tmp/owent/opentelemetry-cpp/build/examples/common/foo_library/libcommon_foo_library.so (0x00007f65438ac000)
        libopentelemetry_exporter_otlp_grpc.so => /tmp/owent/opentelemetry-cpp/build/exporters/otlp/libopentelemetry_exporter_otlp_grpc.so (0x00007f65437f5000)
        libopentelemetry_trace.so => /tmp/owent/opentelemetry-cpp/build/sdk/src/trace/libopentelemetry_trace.so (0x00007f65436f9000)
        libopentelemetry_exporter_otlp_grpc_client.so => /tmp/owent/opentelemetry-cpp/build/exporters/otlp/libopentelemetry_exporter_otlp_grpc_client.so (0x00007f6543176000)
        libstdc++.so.6 => /lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007f6542f94000)
        libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007f6542f79000)
        libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f6542d87000)
        /lib64/ld-linux-x86-64.so.2 (0x00007f6543b93000)
        libopentelemetry_otlp_recordable.so => /tmp/owent/opentelemetry-cpp/build/exporters/otlp/libopentelemetry_otlp_recordable.so (0x00007f6542a57000)
        libopentelemetry_common.so => /tmp/owent/opentelemetry-cpp/build/sdk/src/common/libopentelemetry_common.so (0x00007f6542a42000)
        libopentelemetry_resources.so => /tmp/owent/opentelemetry-cpp/build/sdk/src/resource/libopentelemetry_resources.so (0x00007f6542965000)
        libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f6542816000)
        libssl.so.1.1 => /lib/x86_64-linux-gnu/libssl.so.1.1 (0x00007f6542783000)
        libcrypto.so.1.1 => /lib/x86_64-linux-gnu/libcrypto.so.1.1 (0x00007f65424ad000)
        libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f65424a5000)

[lalitb]

Fix compatibility of OTLP log unit tests for MSVC.

What is the compatibility issue here? Thanks.

[owent]

Did a quick validations on the binaries generated from this PR.

It seems that example_otlp_grpc_log still has dependency on both libopentelemetry_exporter_otlp_grpc.so and libopentelemetry_exporter_otlp_grpc_log.so. Should that be fixed?

$ ldd example_otlp_grpc_log
        linux-vdso.so.1 (0x00007fff86bf5000)
        libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f4b4ef1b000)
        libcommon_logs_foo_library.so => /tmp/owent/opentelemetry-cpp/build/examples/common/logs_foo_library/libcommon_logs_foo_library.so (0x00007f4b4eeb6000)
        libopentelemetry_exporter_otlp_grpc.so => /tmp/owent/opentelemetry-cpp/build/exporters/otlp/libopentelemetry_exporter_otlp_grpc.so (0x00007f4b4edff000)
        libopentelemetry_exporter_otlp_grpc_log.so => /tmp/owent/opentelemetry-cpp/build/exporters/otlp/libopentelemetry_exporter_otlp_grpc_log.so (0x00007f4b4ed48000)
        libopentelemetry_trace.so => /tmp/owent/opentelemetry-cpp/build/sdk/src/trace/libopentelemetry_trace.so (0x00007f4b4ec4a000)
        libopentelemetry_logs.so => /tmp/owent/opentelemetry-cpp/build/sdk/src/logs/libopentelemetry_logs.so (0x00007f4b4eb63000)
        libopentelemetry_exporter_otlp_grpc_client.so => /tmp/owent/opentelemetry-cpp/build/exporters/otlp/libopentelemetry_exporter_otlp_grpc_client.so (0x00007f4b4e5e2000)
        libstdc++.so.6 => /lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007f4b4e400000)
        libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007f4b4e3e5000)
        libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f4b4e1f3000)
        /lib64/ld-linux-x86-64.so.2 (0x00007f4b4f1d1000)
        libopentelemetry_otlp_recordable.so => /tmp/owent/opentelemetry-cpp/build/exporters/otlp/libopentelemetry_otlp_recordable.so (0x00007f4b4dec1000)
        libopentelemetry_common.so => /tmp/owent/opentelemetry-cpp/build/sdk/src/common/libopentelemetry_common.so (0x00007f4b4deae000)
        libopentelemetry_resources.so => /tmp/owent/opentelemetry-cpp/build/sdk/src/resource/libopentelemetry_resources.so (0x00007f4b4ddd1000)
        libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f4b4dc82000)
        libssl.so.1.1 => /lib/x86_64-linux-gnu/libssl.so.1.1 (0x00007f4b4dbef000)
        libcrypto.so.1.1 => /lib/x86_64-linux-gnu/libcrypto.so.1.1 (0x00007f4b4d917000)
        libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f4b4d911000)

While example_otlp_grpc is rightly dependent on only libopentelemetry_exporter_otlp_grpc.so.

$ ldd ./example_otlp_grpc
        linux-vdso.so.1 (0x00007fff1a3e1000)
        libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f6543907000)
        libcommon_foo_library.so => /tmp/owent/opentelemetry-cpp/build/examples/common/foo_library/libcommon_foo_library.so (0x00007f65438ac000)
        libopentelemetry_exporter_otlp_grpc.so => /tmp/owent/opentelemetry-cpp/build/exporters/otlp/libopentelemetry_exporter_otlp_grpc.so (0x00007f65437f5000)
        libopentelemetry_trace.so => /tmp/owent/opentelemetry-cpp/build/sdk/src/trace/libopentelemetry_trace.so (0x00007f65436f9000)
        libopentelemetry_exporter_otlp_grpc_client.so => /tmp/owent/opentelemetry-cpp/build/exporters/otlp/libopentelemetry_exporter_otlp_grpc_client.so (0x00007f6543176000)
        libstdc++.so.6 => /lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007f6542f94000)
        libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007f6542f79000)
        libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f6542d87000)
        /lib64/ld-linux-x86-64.so.2 (0x00007f6543b93000)
        libopentelemetry_otlp_recordable.so => /tmp/owent/opentelemetry-cpp/build/exporters/otlp/libopentelemetry_otlp_recordable.so (0x00007f6542a57000)
        libopentelemetry_common.so => /tmp/owent/opentelemetry-cpp/build/sdk/src/common/libopentelemetry_common.so (0x00007f6542a42000)
        libopentelemetry_resources.so => /tmp/owent/opentelemetry-cpp/build/sdk/src/resource/libopentelemetry_resources.so (0x00007f6542965000)
        libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f6542816000)
        libssl.so.1.1 => /lib/x86_64-linux-gnu/libssl.so.1.1 (0x00007f6542783000)
        libcrypto.so.1.1 => /lib/x86_64-linux-gnu/libcrypto.so.1.1 (0x00007f65424ad000)
        libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f65424a5000)

Yes, but libopentelemetry_exporter_otlp_grpc_log.so and libopentelemetry_exporter_otlp_grpc.so do not link grpc anymore.

[owent]

Fix compatibility of OTLP log unit tests for MSVC.

What is the compatibility issue here? Thanks.

When compiling with the latest MSVC (17.3) , the std::string array can not convert to opentelemetry::common::AttributeValue .
It seems to have some problem to convrert to span<string_view> implicitly.

[lalitb]

Yes, but libopentelemetry_exporter_otlp_grpc_log.so and libopentelemetry_exporter_otlp_grpc.so do not link grpc anymore.

Yes, I can see opentelemetry_exporter_otlp_grpc_client adding the dependency on grpc which seems to be fine. But was just thinking that the actual solution could have been to remove libopentelemetry_exporter_otlp_grpc.so dependency for example_otlp_grpc_log ?

[lalitb]

Yes, but libopentelemetry_exporter_otlp_grpc_log.so and libopentelemetry_exporter_otlp_grpc.so do not link grpc anymore.

>Yes, I can see opentelemetry_exporter_otlp_grpc_client adding the dependency on grpc which seems to be fine. But was just thinking that the actual solution could have been to remove libopentelemetry_exporter_otlp_grpc.so dependency for example_otlp_grpc_log ?

Please ignore this. I just realized it is possible for an instrumentation library to have a dependency on both log and trace exporters.

[lalitb]

Another nit comment, now that the libgrpc.a and libprotobuf.a are statically added in opentelemetry_exporter_otlp_grpc_client.so, we can remove the gRPC dependency from otlp exporter example -

opentelemetry-cpp/examples/otlp/CMakeLists.txt

Line 9 in 951768a

opentelemetry_trace opentelemetry_exporter_otlp_grpc gRPC::grpc++)

Not blocker for this PR as if required it can done later in #1598

[lalitb]

LGTM with nit comments. Thanks for the fix.

[owent]

LGTM with nit comments. Thanks for the fix.

Thanks and gRPC::grpc++ is removed from OTLP examples now.