Add configuration for MCP JSON Rest bridge filter

[paulhong01]

Extension for supporting existing REST backends to function as MCP servers without native MCP support.

Part of #39174

Risk Level: none
Testing: n/a
Docs Changes: yes
Release Notes: n/a
Platform Specific Features: n/a

[repokitteh-read-only]

Hi @paulhong01, 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: #43400 was opened by paulhong01.

see: more, trace.

[repokitteh-read-only]

CC @envoyproxy/coverage-shephards: FYI only for changes made to (test/coverage.yaml).
envoyproxy/coverage-shephards assignee is @RyanTheOptimist
CC @envoyproxy/api-shepherds: Your approval is needed for changes made to (api/envoy/|docs/root/api-docs/).
envoyproxy/api-shepherds assignee is @wbpcode
CC @envoyproxy/api-watchers: FYI only for changes made to (api/envoy/|docs/root/api-docs/).

🐱

Caused by: #43400 was opened by paulhong01.

see: more, trace.

[botengyao]

Nice, thanks for raising this PR, exciting!

/wait

[tyxia]

Thanks for your contribution! Left a high-level comment

[wbpcode]

We don't prefer oneof. And this is more like an enum, right?

[paulhong01]

This is a tagged union, not an enum. These fields must carry a payload: the URL Path Template.

The structure get: "/v1/foo" concisely defines both the HTTP Method (via the field ID) and the Path (via the string value) in a single entry.

[wbpcode]

Get it. Thanks for the explanation.
Although we still could use an enum + string/path to complete same feature?

I personally think the API is fine. But our API style may inclined to no oneof and check it manually in the source code.

But if no oneof, for such many fields, it's not friendly to check them.

Cc @adisuissa WDYT?

[paulhong01]

Yes. An enum + string path can also work. I personally think enum + string path is little bit verbose. Also, The oneof approach structurally guarantees that if a rule exists, the method is known.

That being said, I'm open to change if the reviewer/style guide has any preference. Let me know what you think. Thanks!

[wbpcode]

Thanks for this contribution. Could you add mark this API as WIP, then it's possible to change it with some feedback from actual practices?

[paulhong01]

Thanks for this contribution. Could you add mark this API as WIP, then it's possible to change it with some feedback from actual practices?

Thanks for the review! work_in_progress = true is added in line15. Please let me know if there is any best practice I should follow to mark this API as WIP!