reverse_conn: envoy contrib changes for reverse_connection custom cluster

[basundhara-c]

Commit Message: This PR defines a new custom cluster type "envoy.clusters.reverse_connection" which enables requests to be sent over reverse connections instead of forward connections. This PR is strictly tied with https://github.com/envoyproxy/envoy/pull/37368.

Additional Description: In order to differentiate between requests that need to be sent via a reverse connection vs those to be sent through forward connections, a new cluster type has been defined. The downstream requests to be sent over reverse connections are expected to contain either of the HTTP headers defined in the cluster's typed config, to enable upstream envoy to figure out which downstream node to send the request to,

The Cluster Manager checks whether the connection is intended for a reverse connection cluster, and if so, calls a custom HTTP/2 conn pool to send the request over the reverse connection. 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]]

Hi @basundhara-c, 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.

:cat:

Caused by: https://github.com/envoyproxy/envoy/pull/37932 was opened by basundhara-c.

see: more, trace.

[jmarantz]

/retest

[jmarantz]

@botengyao anything blocking moving forward with a review?

[phlax]

ping @botengyao

[github-actions[bot]]

This pull request has been automatically marked as stale because it has not had activity in the last 30 days. It will be closed in 7 days if no further activity occurs. Please feel free to give a status update now, ping for review, or re-open when it's ready. Thank you for your contributions!

[tyxia]

/wait

@botengyao Is this PR ready to be reviewed again or Is this PR still waiting for https://github.com/envoyproxy/envoy/pull/37368 to land? Thanks!

[github-actions[bot]]

This pull request has been automatically marked as stale because it has not had activity in the last 30 days. It will be closed in 7 days if no further activity occurs. Please feel free to give a status update now, ping for review, or re-open when it's ready. Thank you for your contributions!

[github-actions[bot]]

This pull request has been automatically closed because it has not had activity in the last 37 days. Please feel free to give a status update now, ping for review, or re-open when it's ready. Thank you for your contributions!