`tracing` integration

[khionu]

Yet Another Integration Issue. As with #160, support for tracing would be fantastic.

[nCrazed]

Rocket (a popular web framework) is currently in the process of migrating to tracing, having this integration for when that happens would be very useful.

rwf2/Rocket#1410

[kellpossible]

It would also be good to have support for eyre/color-eyre too along with this.

[khionu]

@kellpossible should open a separate issue for a separate crate to support.

[kellpossible]

I've started working on this https://github.com/kellpossible/sentry-tracing I'll make it into a pull request here when I've tested it out more and sure about the feature set. Happy for any comments, or if someone else wants to rip it out and make a PR of it now.

[Swatinem]

Some preliminary typedefs related to tracing just landed in #276

[dashed]

@kellpossible were you able to generate any useful spans/traces?

[kellpossible]

@dashed I've got events working as breadcrumbs, and issues. Span support is limited at the moment I think, haven't tested it much.

[gakonst]

@kellpossible thank you for the work so far! are you still working on the feature?

[kellpossible]

@gakonst not really, it was working well enough for my purposes at the time, and I'm currently reassigned on a different project which doesn't involve using sentry, but perhaps will come back to it.

[leops]

I've forked @kellpossible's repository to https://github.com/levels3d/sentry-tracing and I'm currently working on adding transaction collection. I've implemented the conversion of tracing spans to sentry span data, but I'm not too sure on how to proceed to submit the transaction to Sentry as wrapping it in an enveloppe and sending that doesn't seem to work properly (there might be an issue in the Sentry SDK as the span IDs are getting serialized as full 32 bytes UUID strings when it looks like they should only be 16 characters long)

[jplatte]

@leops Idk what transaction collection is, but am I right in assuming that I have to use your fork to get span support? It doesn't seem like the official sentry-tracing from this repo currently reports spans to sentry, which makes the reported errors much less useful than they should be.

[leops]

Well my fork is sort of halfway there, while my version does collect spans from the tracing library since the Sentry SDK doesn't really support transactions I tried to pass that data into the SDK anyway in the best way I could find but the resulting transactions never show up in Sentry, and unfortunately at the moment I don't have more time to spend on debugging this.