Configure Envoy to use the same HTTP protocol version used by the
downstream caller when forwarding requests to a local application that
is configured with the protocol set to either `http2` or `grpc`.
This allows upstream applications that support both HTTP/1.1 and
HTTP/2 on a single port to receive requests using either protocol. This
is beneficial when the application primarily communicates using HTTP/2,
but also needs to support HTTP/1.1, such as to respond to Kubernetes
HTTP readiness/liveness probes.
Co-authored-by: Derek Menteer <derek.menteer@hashicorp.com>
Blake Covarrubias