Users can specify metadata in a health check's config that will be
used to select a matching transport socket from those configured in a
cluster's transport_socket_matches. This allows users to configure a
different transport socket for health check connections than the one
that is used to create a connection to an endpoint for proxying.
Risk Level: low; small optional feature
Testing: added unit tests
Docs Changes: updated health check and cluster proto docs with an explanation and example.
Release Notes: added
Fixes#10575
Signed-off-by: Spencer Lewis <slewis@squareup.com>
Mirrored from https://github.com/envoyproxy/envoy @ b6c8bb3a4ac6bcce221643a4924befd5eefd6815