Trace Liveview in Phoenix instrumentation

[derekkraan]

Supercedes #108 since I don't have access to the source repo anymore.

I've removed the parent span that lives for the duration of the liveview process, and instead added thread.name with the pid, so that different events in the same liveview can be correlated to each other (per suggestion from @connorlay).

This sidesteps the whole discussion on monitoring spans. If we decide later that we want an overarching span, then that can always be added in at that point in time.

[tsloughter]

thread.name actually needs to be removed to merge this. That needs to be a general attribute added in the SDK and updated in the spec. I can handle that. If you remove it from here I can merge this.

[derekkraan]

@tsloughter Removed thread.name from the PR as requested. Do you mean that thread.name will be added to all spans from within the SDK?

[tsloughter]

@derekkraan correct. tho needs to be configurable I assume since some SaaS charge for attributes.

[tsloughter]

See open-telemetry/opentelemetry-erlang#550

It has thread.name as the scheduler id because I originally thought it would be that, but I came around to think pid was better.

[tsloughter]

Looks like some formatting issues causing failure.

[derekkraan]

I formatted with Elixir 1.15. I have seen the formatter checks fail between versions of Elixir, are you sure it's not that? (ie the formatter changes sometimes between versions of Elixir)

[tsloughter]

Ah.

We need to change the formatting job to only run on 1 version.

[tsloughter]

Opened #199 to track that

[bryannaegele]

There are no tests for this functionality. Can you get those created in another PR @derekkraan?

[tsloughter]

Yup, need those before any release.

[connorlay]

Hey folks, I'm interested in getting this work published and am happy to help out with tests if needed @derekkraan @tsloughter 🙂

[derekkraan]

I haven't been able to find time yet, so from my side it would be much appreciated!

[skbolton]

Yup, need those before any release.

Now that this the PR for tests has been merged can a new release be made with liveview tracing?

[tielur]

Yup, need those before any release.

I'd love to see a release with this included as well, I'm excited to try out telemetry with liveview