protoc-gen-go-grpc-service-config

README

protoc-gen-go-grpc-service-config

gRPC service config without service discovery, by bundling the service config with the generated code.

How to

Step 1: Add a service config JSON file to your package

There is assumed to be one JSON file per package, named according to: <package>_grpc_service_config.json.

For example src/example/v1/example_grpc_service_config.json:

{
  "methodConfig": [
    {
      "name": [{ "service": "example.v1.ExampleService" }],
      "timeout": "10s",
      "retryPolicy": {
        "initialBackoff": "0.200s",
        "maxBackoff": "60s",
        "maxAttempts": 5,
        "backoffMultiplier": 1.3,
        "retryableStatusCodes": ["UNAVAILABLE"]
      }
    }
  ]
}

Step 2: Run the protoc plugin

Use the required path option to tell the generator where to load JSON files from.
Use the optional validate option to validate that the service config format is valid.
Use the optional required option to require every service to have a service config.

protoc
  -I src \
  --go_out=gen/go \
  --go-grpc_out=gen/go \
  --go-grpc-service-config_out=gen/go \
  --go-grpc-service-config_opt=path=src \
  --go-grpc-service-config_opt=validate=true \
  --go-grpc-service-config_opt=required=true

Your generated code output will now have a Go file corresponding to every service config JSON file.

For example gen/go/example/v1/example_grpc_service_config.json.go:

package examplev1

// ServiceConfig is the service config for all services in the package.
// Source: example_grpc_service_config.json.
const ServiceConfig = `{
  "methodConfig": [
    {
      "name": [{ "service": "example.v1.ExampleService" }],
      "timeout": "10s",
      "retryPolicy": {
        "initialBackoff": "0.200s",
        "maxBackoff": "60s",
        "maxAttempts": 5,
        "backoffMultiplier": 1.3,
        "retryableStatusCodes": ["UNAVAILABLE"]
      }
    }
  ]
}
`

Step 3: Use your bundled service config when dialing

conn, err := grpc.DialContext(
	ctx,
	"example.com:443",
	grpc.WithDefaultServiceConfig(examplev1.ServiceConfig),
)