Add metaprotocol proxy api

[zhaohuabing]

Signed-off-by: zhaohuabing zhaohuabing@gmail.com

Propose a common framework for layer-7 protocols ( a generic proxy): #18761

Design: https://istio.io/latest/blog/2021/aeraki/
Full implementation(I'll move it into Envoy repo later): https://github.com/aeraki-framework/meta-protocol-proxy

Related issues:
generic proxy support: #18209
Generic Access Log: #13085
Generic Routing & Rds: #9656

Commit Message:
Additional Description:
Risk Level: low
Testing: The full implementation has been tested with Dubbo, Thrift, and tRPC(a proprietary protocol used in Tencent) . Please refer to this link for details: https://github.com/aeraki-framework/meta-protocol-proxy#test-metaprotocol-proxy
Docs Changes:
Release Notes:
Platform Specific Features:
[Optional Runtime guard:]
[Optional Fixes #Issue]
[Optional Fixes commit #PR or SHA]
[Optional Deprecated:]
[Optional API Considerations:]

[repokitteh-read-only]

Hi @zhaohuabing, welcome and thank you for your contribution.

We will try to review your Pull Request as quickly as possible.

In the meantime, please take a look at the contribution guidelines if you have not done so already.

🐱

Caused by: #18768 was opened by zhaohuabing.

see: more, trace.

[repokitteh-read-only]

CC @envoyproxy/api-shepherds: Your approval is needed for changes made to (api/envoy[\w/]*/(v1alpha\d?|v1|v2alpha\d?|v2))|(api/envoy/type/(matcher/)?\w+.proto).
CC @envoyproxy/api-shepherds: Your approval is needed for changes made to api/envoy/.
envoyproxy/api-shepherds assignee is @htuch
CC @envoyproxy/api-watchers: FYI only for changes made to api/envoy/.

🐱

Caused by: #18768 was opened by zhaohuabing.

see: more, trace.

[htuch]

Thanks for the contribution. This is really nice architectural pattern and will be super valuable IMHO. Can you comment on where you are in the https://github.com/envoyproxy/envoy/blob/main/EXTENSION_POLICY.md#adding-new-extensions process before I start review?

[zhaohuabing]

Thanks for the contribution. This is really nice architectural pattern and will be super valuable IMHO. Can you comment on where you are in the https://github.com/envoyproxy/envoy/blob/main/EXTENSION_POLICY.md#adding-new-extensions process before I start review?

@htuch I'm in process 1 and trying to find sponsors. Would you be interested in sponsoring this feature?

[wbpcode]

Similar PR: #18765

[zhaohuabing]

It seems that it doesn't require a sponsor for a contrib extension: https://docs.google.com/document/d/1yl7GOZK1TDm_7vxQvt8UQEAu07UQFru1uEKXM6ZZg_g/edit#heading=h.qoel4u1w3lpe

[wbpcode]

I am not sure, but may be here is the final requirements 🤔 : https://github.com/envoyproxy/envoy/blob/main/CONTRIBUTING.md#adding-contrib-extensions

[mattklein123]

Per #18209 (comment), can we put this on hold until we have a design?

Also, a very quick high level comment is that I think we should make sure to use the new generic matching infrastructure in whatever we do. Thank you! cc @snowp

/wait

[htuch]

So yeah, let's move this to #18209. I'm going to close the PR out for now as it's likely to become stale by time we have a unified design and review carried out. Happy to reopen when we are ready to proceed.

Re: maintainer sponsorship, I wish :) Unfortunately I don't have cycles for anything this epic (and totally impactful!). We can try find someone if we decide to go to core Envoy vs. contrib/ in the issue.