HTTPRoute sessionPersistence: allow overriding cookie Path attribute

[zhaohuabing]

Description:

Envoy Gateway currently derives the session persistence cookie Path from the matched HTTPRoute path.
This becomes a problem when traffic is rewritten at an edge layer before it reaches Envoy Gateway.

Example flow:

1. A client sends a request to https://example.com/
2. An upstream edge/proxy rewrites that request to https://example.com/foo/bar
3. Envoy Gateway matches the rewritten path /foo/bar
4. sessionPersistence sets a cookie with Path=/foo/bar
5. On the next request to https://example.com/, the browser does not send that cookie back because cookie path matching does not include /
6. As a result, sticky sessions break even though the user-facing URL is still rooted at /.

Possible workaround:

• Enhance sessionPersistence in HTTPRoute to add support for modifying Path attribute - this needs Gateway API upstream change
• Add a similar config in BackendTrafficPolicy  to allow for more flexibility of updating cookie attributes like here

[optional Relevant Links:]

Any extra documentation required to understand the issue.

[zhaohuabing]

Raised kubernetes-sigs/gateway-api#4713 to relax route-level cookie Path handling and consider explicit Path configuration for sessionPersistence.

[github-actions]

This issue has been automatically marked as stale because it has not had activity in the last 30 days.

[github-actions]

This issue has been automatically marked as stale because it has not had activity in the last 30 days.