6.6. Interacting with a serverless application using HTTP2 and gRPC

OpenShift Serverless supports only insecure or edge-terminated routes.

Insecure or edge-terminated routes do not support HTTP2 on OpenShift Container Platform. These routes also do not support gRPC because gRPC is transported by HTTP2.

If you use these protocols in your application, you must call the application using the ingress gateway directly. To do this you must find the ingress gateway’s public address and the application’s specific host.

Procedure

  1. Find the application host. See the instructions in Verifying your serverless application deployment.

  2. Find the ingress gateway’s public address: 

    $ oc -n knative-serving-ingress get svc kourier
    NAME                   TYPE           CLUSTER-IP      EXTERNAL-IP                                                             PORT(S)                                                                                                                                      AGE
kourier   LoadBalancer   172.30.51.103   a83e86291bcdd11e993af02b7a65e514-33544245.us-east-1.elb.amazonaws.com   80:31380/TCP,443:31390/TCP   67m

    The public address is surfaced in the EXTERNAL-IP field. In this case, it would be a83e86291bcdd11e993af02b7a65e514-33544245.us-east-1.elb.amazonaws.com.

  3. Manually set the host header of your HTTP request to the application’s host, but direct the request itself against the public address of the ingress gateway.

    The following example uses the information obtained from the steps in Verifying your serverless application deployment:

    Example command

    $ curl -H "Host: hello-default.example.com" a83e86291bcdd11e993af02b7a65e514-33544245.us-east-1.elb.amazonaws.com

    Example output

    Hello Serverless!

    You can also make a gRPC request by setting the authority to the application’s host, while directing the request against the ingress gateway directly: 

    grpc.Dial(
    "a83e86291bcdd11e993af02b7a65e514-33544245.us-east-1.elb.amazonaws.com:80",
    grpc.WithAuthority("hello-default.example.com:80"),
    grpc.WithInsecure(),
)
    注意

    Ensure that you append the respective port, 80 by default, to both hosts as shown in the previous example.