Introduce a new stateful session extension. This is a change after #17848#17290.
In #17290, we added a new cross-priority host map for fast host searching. In #17848, we extend `LoadBalancerContext` interface to provide an override host and to select the upstream host by the override host.
Finally, in this change, we expand a new API to allow users to extract the state of the session from the request and change the result of load balancing by setting the override host value.
Related doc: https://docs.google.com/document/d/1IU4b76AgOXijNa4sew1gfBfSiOMbZNiEt5Dhis8QpYg/edit?usp=sharing.
Risk Level: Medium
Testing: Added
Docs Changes: Added
Release Notes: Added
Platform-Specific Features: N/A.
Signed-off-by: wbpcode <wbphub@live.com>
Mirrored from https://github.com/envoyproxy/envoy @ fb2aad0303bbbcb0daabf6940c6ad97252995b98
data-plane-api(Azure Pipelines)