i-love-flamingo / grpc

Flamingo GRPC Module

GRPC Module

This module can be used to run a grpc server in your flamingo application. It uses the google grpc implementation and makes it easy to use within a flamingo application.

Before you start using this module - it makes sense to be familiar with the official grpc go tutorials

The module provides:

• Starting of a grpc server with the registered grpc services
• A concept to bind grpc services (in our own modules)
• Providing authentication features, that can be used to secure grpc services. For example by using OAuth tokens in a bearer request header.

How to use it

1. Generate: Define your grpc service in your .proto file. And generate the go client and server.
2. Service Implementation: Implementing the service interface generated from our service definition: doing the actual “work” of our service.
3. Binding: Inside your module you need to register the service implementation. This is done like this:

func (m *SampleModule) Configure(injector *dingo.Injector) {
	injector.BindMulti(new(grpc.ServerRegister)).ToProvider(serverRegisterProvider)
}

func serverRegisterProvider(s *ServiceImplementation) grpc.ServerRegister {
	return func(server grpc.ServerRegistrar) {
		generated.RegisterExampleServiceServer(server, s)
	}
}

Where ServiceImplementation is your implementation of the generated service interface. And RegisterExampleServiceServer is the generated helper method to register.

4. Add flamingo grpc server: Inside your main.go add the grpc.ServerModule to the flamingo bootstrap.
5. You may now configure the authenticators inside your configuration:

grpc.identifier: test

Example

See the example application inside this module. The grpc server start on the default port :11101

Authenticators

To enable OAuth bearer authentication add this to your config.cue

grpc: identifier: [
    {"identifier": "management", "provider": "oauth2", "issuer": "http://localhost:8080/auth/realms/testreal", "clientID": "sampleapp"},
]