http: Add content-based health check for upstream

[botengyao]

Signed-off-by: Boteng Yao [email protected]

Added the HTTP content-based health check for upstream.

• The health check should pass if the checker finds the expected string within the first response_buffer_size bytes of the HTTP response body.
• There is still status code check after the response check.
• This is an optional feature for health check. Here is some context.

Commit Message: http: Add HTTP content-based health check for upstream Additional Description: Risk Level: M Testing: fuzz & integration test 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 @markdroth 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/22212 was opened by botengyao.

see: more, trace.

[adisuissa]

/assign-from @envoyproxy/first-pass-reviewers

[repokitteh-read-only[bot]]

@envoyproxy/first-pass-reviewers assignee is @tonya11en

:cat:

Caused by: a https://github.com/envoyproxy/envoy/pull/22212#issuecomment-1185836750 was created by @adisuissa.

see: more, trace.

[botengyao]

If there's a healthcheck benchmark, can you also post the before/after results? Also, can you add some more context and/or a pointer to an issue that contains the context in the PR description? Thanks!

This is an optional feature. Basically, we want to add the support for Envoy to correspond with this Google Cloud content-based health check feature. There should be some additional costs because we match the maximum 1024 bytes string.

[phlax]

@botengyao - requires main merge

/wait

[botengyao]

@envoyproxy/api-shepherds for anther look. Thank you!

[phlax]

/docs

[repokitteh-read-only[bot]]

Docs for this Pull Request will be rendered here:

https://storage.googleapis.com/envoy-pr/22212/docs/index.html

The docs are (re-)rendered each time the CI envoy-presubmit (precheck docs) job completes.

:cat:

Caused by: a https://github.com/envoyproxy/envoy/pull/22212#issuecomment-1201413314 was created by @phlax.

see: more, trace.

[kyessenov]

/assign @adisuissa for finishing API review.