generic proxy: tracing support for the generic proxy based on the generic tracing

[wbpcode]

Commit Message: generic proxy: tracing support for the generic proxy based on the generic tracing
Additional Description:

Add tracing support to the generic proxy.

Risk Level: Low.
Testing: n/a.
Docs Changes: n/a.
Release Notes: wait.
Platform Specific Features: n/a.

[wbpcode]

Before formal working on this, there is a problem need to be clarified first.

Should I create a new Tracing proto message in the api/config/tracing/v3 or somewhere for protocol-independent usage?

Tracing should be protocol independent but current Tracing proto message in the api/extensions/filters/network/http_connnection_manager/v3 is HTTP specific.

cc @envoyproxy/api-shepherds @envoyproxy/api-watchers

And there is a related issue #22695. cc @mattklein123 do you have some new idea to this problem?

[htuch]

This is probably a place that we would refactor if we could I think. In the absence of that option, we could either deprecate the one in HCM and move to a more neutral location as you suggest (lots of impacted users, somewhat cleaner) or have generic proxy take an HCM proto dependency (fragile, logically nonsensical but probably the least impactul). The alternative, of maintaining two parallel tracing top-level config protos with the same fields, is not great, since it means perma-skew in features and is a PITA to maintain. Any other thoughts here?

[mattklein123]

or have generic proxy take an HCM proto dependency (fragile, logically nonsensical but probably the least impactul)

I would probably vote for this just to avoid churn. We have made similar compromises in the past like this.

[wbpcode]

or have generic proxy take an HCM proto dependency (fragile, logically nonsensical but probably the least impactul)

I would probably vote for this just to avoid churn. We have made similar compromises in the past like this.

It's acceptable for me.

But it would be better to record this to somewhere to tell future developers it's a compormise rather than a design or error. 🤔

[KBaichoo]

/wait

for formatting

@htuch I think this is waiting on your input

[htuch]

/lgtm api

[repokitteh-read-only]

no relevant owners for "api"

🐱

Caused by: a #24790 (review) was submitted by @htuch.

see: more, trace.

[htuch]

@wbpcode there are a lot of TODOs and no tests yet, are you planning on adding more to this PR? If so, please LMK when ready for contrib review/merge, thanks.

[wbpcode]

@wbpcode there are a lot of TODOs and no tests yet, are you planning on adding more to this PR? If so, please LMK when ready for contrib review/merge, thanks.

Some pre-work need to be completed first in other PRs.

I will mark this as waiting before I complete everything. Thanks.

/wait

[wbpcode]

This is ready for a review. And some core code modifications are split out to #25420.

cc @htuch cc @soulxu

[htuch]

/lgtm api

[repokitteh-read-only]

no relevant owners for "api"

🐱

Caused by: a #24790 (review) was submitted by @htuch.

see: more, trace.

[htuch]

@soulxu can you take a look as CODEOWNER? Thanks.

[wbpcode]

/retest

[repokitteh-read-only]

Retrying Azure Pipelines:
Retried failed jobs in: envoy-presubmit

🐱

Caused by: a #24790 (comment) was created by @wbpcode.

see: more, trace.

[soulxu]

no more question, LGTM, thanks

[wbpcode]

I think I forgot the changelog. I will add it.

[wbpcode]

Hi, @soulxu, could you give a new LGTM to this PR? Thanks. 🙇

[wbpcode]

And friendly ping @htuch