Monitor grpc traffic via devtools

[mehmetf]

Currently devtools can monitor HTTP traffic. Some transport implementations (in particular package:grpc) operate directly on dart:io Socket. The ideal goal of this would be:

• Monitor socket traffic.
• Be able to interpret and decode grpc traffic (protos) and show details about the payload in the tooling

@yohanln has mentioned this would be a good intern project.

[mehmetf]

Also @jacob314 and @bkonyi as FYI

[bkonyi]

@zichangg has actually already implemented socket profiling in dart:io, I just haven't gotten around to surfacing it in DevTools yet (I'll hopefully get around to it in Q3).

[zichangg]

Right! But my implementation is only monitoring statistics of socket(without looking at the content). It probably needs more work for grpc.

[devoncarew]

For fully exposing networking info, we might look at the chrome debug protocol for inspiration - their API seems full featured for what you'd need to build a network profiling client: https://chromedevtools.github.io/devtools-protocol/1-3/Network/.

[thedejifab]

Is anyone working on this at the moment? Currently building stuff using GRPC and I need to monitor my traffic as I do with REST API calls but this is a blocker.

[zichangg]

We will start the work very soon!

[thedejifab]

Cool @zichangg. I think I'm actually interested in working on this

[kenzieschmoll]

There is an in-progress CL for this. @bkonyi is going to pick up on the existing work when he has some bandwidth.

[kenzieschmoll]

Some work for this effort was landed here: grpc/grpc-dart#392, but we need to audit what work is left to be done to support debugging gRPC requests with DevTools