Proxy gRPC Traffic

Google Remote Procedure Call (gRPC) is an open-source high-performance Remote Procedure Call (RPC) framework based on HTTP/2 protocol. It uses Protocol Buffers (protobuf) as the Interface Description Language (IDL). API7 Enterprise provides crucial functionalities such as protocol conversion, load balancing, authentication, and authorization, enhancing the potential of gRPC.

This guide shows how to use API7 Enterprise to proxy traffic for gRPC services.

Below is an interactive demo that provides a hands-on introduction to proxying gRPC traffic using API7 Enterprise.

Prerequisites

1. Install API7 Enterprise.
2. Complete Deploy with API7 Ingress Controller on Kubernetes if needed.
3. Install gRPCurl to send requests to gRPC services for validation.

Deploy an Example gRPC Server

API7 provides an example gRPC service for testing. You can start the service in Docker or Kubernetes, depending on your API7 installation.

Start a Server

Docker

Start an example gRPC server in Docker listening on port 50051:

docker run -d \
  --name grpc-service \
  --network=api7-ee_api7 \
  -p 50051:50051 \
  --restart always api7/grpc-server-example:1.0.0

Kubernetes

Start an example gRPC server listening on port 50051:

kubectl run grpc-service \
  --image=api7/grpc-server-example:1.0.0 \
  --port=50051 \
  --restart=Always

You should see a pod/grpc-service created response.

Verify Installation

Docker

Kubernetes

Expose the application's port 50051 through a service:

kubectl expose pod grpc-service --port 50051

You should see a service/grpc-service exposed response.

Port forward 50051 of the service to localhost:

kubectl port-forward svc/grpc-service 50051:50051 &

Verify whether the gRPC server starts successfully by listing all available gRPC services and methods:

grpcurl -plaintext 127.0.0.1:50051 list

You should see the following output:

grpc.reflection.v1alpha.ServerReflection
helloworld.Greeter
helloworld.TestImport

List all the available methods for the helloworld.Greeter service:

grpcurl -plaintext 127.0.0.1:50051 list helloworld.Greeter

You should see the following output:

helloworld.Greeter.GetErrResp
helloworld.Greeter.Plus
helloworld.Greeter.SayHello
helloworld.Greeter.SayHelloAfterDelay
helloworld.Greeter.SayHelloBidirectionalStream
helloworld.Greeter.SayHelloClientStream
helloworld.Greeter.SayHelloServerStream

Create a Service and a Route

In this section, you will be creating a service with a route that proxies traffic to the example gRPC service.

Dashboard

Create a Service

1. Select Published Services of your gateway group from the side navigation bar, then click Add Service.
2. Select Add Manually.
3. From the dialog box, do the following:

• In the Name field, enter grpc-example.
• In the Service Type field, choose HTTP(Layer 7 Proxy).
• In the Upstream Scheme field, choose gRPC.
• In the How to find the upstream field, choose Use Nodes.
• Click Add Node.
• From the Add Node dialog box, do the following:
  • In the Host field, enter your private IP address, such as 192.168.2.103. In the Port field, enter 50051. In the Weight field, use the default value 100.
• Click Add.

Create a Route

1. Inside the service that you just created in the previous step and then click Add Route.
2. From the dialog box, do the following:

• In the Name field, enter helloworld.Greeter.
• In the Path field, enter helloworld.Greeter/SayHello.
• In the Methods field, choose GET and POST.
• Click Add.

ADC

Create an ADC configuration file to configure a route to the gRPC service:

adc.yaml

services:
  - name: grpc-example
    upstream:
      name: gRPC Upstream
      scheme: grpc
      type: roundrobin
      nodes:
        - host: 192.168.2.103
          port: 50051
          weight: 100
    routes:
      - uris:
          - /helloworld.Greeter/SayHello
        name: helloworld.Greeter
        methods:
          - GET
          - POST

Synchronize the configuration to API7 Gateway:

adc sync -f adc.yaml

Ingress Controller

Create a Kubernetes manifest file to configure a route to the gRPC service using the ApisixRoute custom resource:

grpc-route.yaml

apiVersion: apisix.apache.org/v2
kind: ApisixRoute
metadata:
  name: grpc-route
  # namespace: api7    # replace with your namespace
spec:
  http:
    - name: helloworld-greeter
      match:
        paths:
          - /helloworld.Greeter/SayHello
        methods:
          - GET
          - POST
      backends:
        - serviceName: grpc-service
          servicePort: 50051

Create another Kubernetes manifest file to configure the upstream schema to grpc using the ApisixUpstream custom resource:

grpc-upstream.yaml

apiVersion: apisix.apache.org/v2
kind: ApisixUpstream
metadata:
  name: grpc-service
# namespace: api7    # replace with your namespace
spec:
  scheme: grpc

Apply the configurations to your cluster:

kubectl apply -f grpc-route.yaml -f grpc-upstream.yaml

Update API7 Gateway to Allow HTTP/2

By default, API7 gateway instance supports TLS-encrypted HTTP/2 on port 9443. For non-encrypted HTTP/2, you can add a new port to the gateway configuration.

In this section, you will be updating the API7 Gateway configuration and deployment to support non-encrypted HTTP/2 on 9081.

Docker

Since Docker does not support updating port mappings while the container is running, first remove the api7-ee-gateway-1 gateway container started with the installation.

Next, start a new gateway instance in Docker. Before running the generated deployment command, add the -p 9081:9081 flag. Your command after modification should look similar to:

docker run -d -e API7_CONTROL_PLANE_ENDPOINTS='["https://<YOUR_IP_ADDR>:7943"]' \
  -e API7_GATEWAY_GROUP_SHORT_ID=default \
  -e API7_CONTROL_PLANE_CERT="-----BEGIN CERTIFICATE-----
  <CERT_CONTENT>
  -----END CERTIFICATE-----
  " \
  -e API7_CONTROL_PLANE_KEY="-----BEGIN PRIVATE KEY-----
  <PRIVATE_KEY_VALUE>
  -----END PRIVATE KEY-----
  " \
  -e API7_CONTROL_PLANE_CA="-----BEGIN CERTIFICATE-----
  <CERT_CONTENT>
  -----END CERTIFICATE-----
  " \
  -e API7_CONTROL_PLANE_SNI="api7ee3-dp-manager" \
  -p 9080:9080 \
  -p 9081:9081 \
  -p 9443:9443 \
  api7/api7-ee-3-gateway:<VERSION>

Run the command to start the gateway.

Once the gateway is running, update the gateway configuration to allow HTTP/2 on port 9081:

docker exec <api7-ee-gateway-container-name> /bin/sh -c "echo '
nginx_config:
  error_log_level: warn

apisix:
  node_listen:
    - port: 9080
      enable_http2: true
    - port: 9081
      enable_http2: true
' > /usr/local/apisix/conf/config.yaml"

Reload the container for configuration changes to take effect:

docker exec <api7-ee-gateway-container-name> apisix reload

Kubernetes

Edit the gateway ConfigMap:

kubectl edit cm api7-ee-3-gateway

Add the configuration to allow HTTP/2 on 9081 in the ConfigMap:

apisix:
  node_listen:
    - port: 9080
      enable_http2: false
    - port: 9081
      enable_http2: true

Save the ConfigMap and restart the deployment:

kubectl rollout restart deployment api7-ee-3-gateway

To add 9081 as a service port, edit the service:

kubectl edit svc/api7-ee-3-gateway-gateway

Add the following configuration to ports:

spec:
  ports:
    ...
    - name: http2-non-tls
      port: 9081
      protocol: TCP
      targetPort: 9081
    ...

Save the service manifest for changes to take effect.

Verify Configurations

Download the helloworld.proto file here.

This example uses the helloworld.proto file to ensure the gRPCurl CLI tool aligns the request and response format with the gRPC service definition.

Docker

If you have installed the gateway instance in Docker and use Dashboard or ADC for configurations, send a request to the route:

Kubernetes

If you have installed the gateway instance on Kubernetes and use Ingress Controller for configurations, first expose the service port to your local machine by port forwarding:

kubectl port-forward svc/api7-ee-3-gateway-gateway 9081:9081 &

Send a request to the route:

grpcurl -plaintext \
  -proto helloworld.proto \
  -d '{"name":"API7"}' \
  "127.0.0.1:9081" \
  "helloworld.Greeter.SayHello"

You should see the following output:

{
  "message": "Hello API7"
}

Additional Resources

• Key Concepts
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  • Routes
  • Plugins