feat(opentelemetry_grpc): add initial setup for opentelemetry_grpc

[yordis]

Signed-off-by: Yordis Prieto [email protected]

[sleipnir]

LGTM

[sleipnir]

@yordis I'm not a maintainer of this project, but PR looks good to me

[yordis]

@sleipnir do you mind giving it another code review; by now

[sleipnir]

Just minor comments, we're getting there, congratulations.

What do you think about adding a small benchmark, comparing the interceptor for client and server? If it's not too much work, of course.

[yordis]

@sleipnir thank you so much for the review; I am gonna wait for @tsloughter input to tackle the comments and other things, some of them are there to actually help me to make sense of things, I honestly keep getting confused with Linking vs Child; and a nice pattern to follow

[tsloughter]

Thanks for reviewing @sleipnir

[tsloughter]

It doesn't have to be this way, but it might be a little cleaner if everything was done in the interceptors, instead of creating the spans in telemetry events and doing context propagation in the interceptor.

[yordis]

@tsloughter the downside of doing that is that, you need to register the interceptor for every single client;
I can write an interceptor, but I would still have a way to enable things globally in the system so developers do not need to worry about it

[sleipnir]

Thanks for reviewing @sleipnir

You're welcome <3