Integrate with OpenCensus stats collection and distributed tracing framework

[PiotrSikora]

Google just released OpenCensus, which is (emphasis mine):

A single distribution of libraries that automatically collects traces and metrics from your app, displays them locally, and sends them to any analysis tool.

The key features of OpenCensus include:

1. Standard wire protocols and consistent APIs for handling trace and metric data.
2. A single set of libraries for many languages, including Java, C++, Go, .Net, Python, PHP, Node.js, Erlang, and Ruby.
3. Included integrations with web and RPC frameworks, making traces and metrics available out of the box.
4. Included exporters for storage and analysis tools. Right now the list includes Zipkin, Prometheus, Jeager, Stackdriver, and SignalFx.
5. Full open source availability for additional integrations and export options.
6. No additional server or daemon is required to support OpenCensus.
7. In process debugging: an optional agent for displaying request and metrics data on instrumented hosts.

This could potentially be a replacement for all the custom tracing frameworks we support in Envoy.

cc @mattklein123 @alyssawilk @htuch

[mattklein123]

@PiotrSikora I believe that OpenCensus trace driver support is already being started. I don't see us deleting the other trace providers (at least in the near term) but would love to provide this as an option.

[stale]

This issue has been automatically marked as stale because it has not had activity in the last 30 days. It will be closed in the next 7 days unless it is tagged "help wanted" or other activity occurs. Thank you for your contributions.

[stale]

This issue has been automatically closed because it has not had activity in the last 37 days. If this issue is still valid, please ping a maintainer and ask them to label it as "help wanted". Thank you for your contributions.

[mpuncel]

I'm curious about the interest levels in this as well. Because OpenCensus defines the context propagation format, it seems like getting Envoy to play with that will be critical for anyone who wants to use OpenCensus for tracing

[htuch]

@bogdandrutu can you provide the latest thinking here FTR.

[mpuncel]

As a potential smaller step supporting the OpenCensus binary trace context propagation format in the existing Zipkin tracer would be useful in deployments using a Zipkin-compatible tracing backend

[stale]

This issue has been automatically marked as stale because it has not had activity in the last 30 days. It will be closed in the next 7 days unless it is tagged "help wanted" or other activity occurs. Thank you for your contributions.

[mattklein123]

Marking help wanted. This should be a straightforward change to add a new OC trace driver.

[moderation]

See additional information and history re: OpenCensus in Envoy at envoyproxy/data-plane-api#345 (comment). It would be good to fix the current non-functioning TraceService code or remove it if the implementation or plans change.

[bogdandrutu]

@g-easy can you please take care of this?

[g-easy]

I have a prototype of an OpenCensus trace driver, I'll roll a PR soon.

[g-easy]

As per the update, the OpenCensus trace driver is in #5387. Please take a look. :)

[mattklein123]

I think this is done!