API to support sampling behavior in xDS matcher

[yanjunxiang-google]

This is the API change for issue: https://github.com/envoyproxy/envoy/issues/30147.

Adding a skip_percentage in the Matcher proto to control how much percentage of traffic will go to ext_proc or logging server after matching condition is met.

The name of the configuration is skip_percentage not sampling_percentage as by default skip_percentage is zero. sampling_percentage = 1 - skip_percentage.

Commit Message: Additional Description: Risk Level: Testing: 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[bot]]

CC @envoyproxy/api-shepherds: Your approval is needed for changes made to (api/envoy/|docs/root/api-docs/). envoyproxy/api-shepherds assignee is @htuch CC @envoyproxy/api-watchers: FYI only for changes made to (api/envoy/|docs/root/api-docs/).

:cat:

Caused by: https://github.com/envoyproxy/envoy/pull/34325 was opened by yanjunxiang-google.

see: more, trace.

[yanjunxiang-google]

/assign @htuch @rshriram @kyessenov

[jmarantz]

/wait (for CI to be green)

[yanjunxiang-google]

/assign @yanavlasov @tyxia

[yanjunxiang-google]

For reviewers, the complete prototyping of the solution is: https://github.com/envoyproxy/envoy/pull/34611.

[tyxia]

There is ongoing discussion internally on the direction of this PR. We can start the review once that is settled.

BTW, @yanjunxiang-google should we just review https://github.com/envoyproxy/envoy/pull/34611, which has complete picture of this feature. I don't have strong opinion though

[yanjunxiang-google]

There is ongoing discussion internally on the direction of this PR. We can start the review once that is settled.

BTW, @yanjunxiang-google should we just review #34611, which has complete picture of this feature. I don't have strong opinion though.

I am fine either to review the API separately or review the entire solution as a whole. Review the API separately has the benefit to focus on the API and get it approved before going into the details of the implementation.

BTW, I think we reached an agreement to go with this approach, right?

[yanjunxiang-google]

Noticed https://github.com/envoyproxy/envoy/pull/34611 is being reviewed. Let me close this PR.