gRPC Routing

The GRPCRoute is used to route gRPC request to backend service. It can match requests by hostname, gRPC service, gRPC method, or HTTP/2 header.

Prerequisites

• Kubernetes cluster version v1.21.0 or higher.
• kubectl CLI
• FSM Gateway installed via guide doc.

Demonstration

Deploy sample

kubectl create namespace grpcbin
kubectl apply -n grpcbin -f https://raw.githubusercontent.com/flomesh-io/fsm-docs/main/manifests/gateway/gprc-routing.yaml

In gRPC case, the listener configuration is similar with HTTP routing.

gRPC Route

We configure the match rule using service: hello.HelloService and method: SayHello to direct traffic to the target service.

rules:
- matches:
  - method:
      service: hello.HelloService
      method: SayHello
  backendRefs:
  - name: grpcbin
    port: 9000

Let’s test our configuration now.

Test

To test gRPC service, we will test with help of the tool grpcurl.

Let’s record the IP address of gateway first.

export GATEWAY_IP=$(kubectl get svc -n grpcbin -l app=fsm-gateway -o jsonpath='{.items[0].status.loadBalancer.ingress[0].ip}')

Issue a request using the grpcurl command, specifying the service name and method. Doing so will yield the correct response.

grpcurl -plaintext -d '{"greeting":"Flomesh"}' $GATEWAY_IP:8000 hello.HelloService/SayHello
{
  "reply": "hello Flomesh"
}