Configure Cloud Run on Anthos to forward HTTP2 - google-cloud-platform

Question

How do you make Cloud Run for Anthos forward incoming HTTP2 requests to a Cloud Run service as HTTP2 instead of HTTP/1.1?
I'm using GCP with Cloud Run for Anthos to deploy a Java application that runs a GRPC server. The Cloud Run app is exposed publicly. I have also configured Cloud Run for Anthos with an SSL cert. When I try to use a GRPC client to call my service, client sends request over HTTP2 which the load balancer accepts but then when the request is forwarded to my Cloud Run service (a Java application running GRPC server), it comes in as HTTP/1.1 and gets rejected by the GRPC server. I assume somewhere between the k8 load balancer and my k8 pod, the request is being forwarded as HTTP/1.1 but I don't see how to fix this.

Answer 1

Bringing to together #whlee's answer and his very important followup comment, here's exactly what I had to do to get it to work.
You must deploy using gcloud cli in order to change the named port. The UI does not allow you to configure the port name. Deploying from service yaml is currently a beta feature. To deploy, run: gcloud beta run services replace /path/to/service.yaml
In my case, my service was initially deployed using the GCP cloud console UI, so here are the steps I ran to export and replace.
Export my existing service (named hermes-grpc) to yaml file:
gcloud beta run services describe hermes-grpc --format yaml > hermes-grpc.yaml
Edit my export yaml and make the following edits:
replaced:
ports:
- containerPort: 6565
with:
ports:
- name: h2c
containerPort: 6565
deleted the following lines:
tcpSocket:
port: 0
Deleted the name: line from the section
spec:
template:
metadata:
...
name:
Finally, redeploy service from edited yaml:
gcloud beta run services replace hermes-grpc.yaml
In the end my edited service yaml looked like this:
apiVersion: serving.knative.dev/v1alpha1
kind: Service
metadata:
annotations:
client.knative.dev/user-image: interledger4j/hermes-server:latest
run.googleapis.com/client-name: cloud-console
creationTimestamp: '2020-01-09T00:02:29Z'
generation: 3
name: hermes-grpc
namespace: default
selfLink: /apis/serving.knative.dev/v1alpha1/namespaces/default/services/hermes-grpc
spec:
template:
metadata:
annotations:
autoscaling.knative.dev/maxScale: '2'
autoscaling.knative.dev/minScale: '1'
run.googleapis.com/client-name: cloud-console
spec:
containerConcurrency: 80
containers:
image: interledger4j/hermes-server:latest
name: user-container
ports:
- name: h2c
containerPort: 6565
readinessProbe:
successThreshold: 1
resources:
limits:
cpu: 500m
memory: 384Mi
timeoutSeconds: 300
traffic:
- latestRevision: true
percent: 100

Answer 2

https://github.com/knative/docs/blob/master/docs/serving/samples/grpc-ping-go/README.md
Describes how to configure named port to make HTTP/2 work