Support HTTP/2 upstream

[psalaberria002]

Please describe your use case / problem. In Envoy it is possible to set alpn_protocols: h2 for upstream services so the connections are HTTP/2. For that to work http2_protocol_options must be set as explained in https://www.envoyproxy.io/docs/envoy/latest/api-v2/api/v2/cds.proto#cluster .

I noticed that the grpc flag in the Mappings sets http2_protocol_options already, but my service is not grpc, and it seems hacky to abuse the flag for making HTTP/2 work :) See https://github.com/datawire/ambassador/blob/4b57121fdf8289f0baa71de6dc9d4d94e486b49c/python/ambassador/envoy/v2/v2cluster.py#L67-L68

Describe the solution you'd like If alpn_protocols contains h2, http2_protocol_options should be set in the cluster config. I assume the grpc flag does more than just setting that field in the configs.

---
apiVersion: getambassador.io/v1
kind: Mapping
metadata:
  name: http2-test
spec:
  prefix: /http2-test
  service: "https://http2-test"
  tls: http2-test
  grpc: True # ??? What's the purpose of this flag? Is it only there for adding http2_protocol_options? If so, maybe that should be renamed.
---
apiVersion: getambassador.io/v1
kind: TLSContext
metadata:
  name: http2-test
spec:
  alpn_protocols: h2
  min_tls_version: v1.2
  secret: ambassador-dev-certs

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[psalaberria002]

Should not be closed

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[psalaberria002]

Still an issue.

[daudo]

jumping on board, too. I'm quite surprised that it doesn't seem to be (officially) supported yet.

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[psalaberria002]

should not be closed

[kflynn]

Pinning this so it won't go stale again. @psalaberria002, the http2_protocol_options is currently the only thing the grpc flag affects, but... yeah, I hear you, it's not the Right Way™ to manage that.

[iNoahNothing]

It appears we forgot to reopen it along with pinning 🙂