github.com/cassioroos/grpc_currency

Currency Service

This is a simple test of GRPC, the idea is to enrich this server later.

Installing dependencies

You will have to install protoc to generate the code and grpcurl to test the code.

Linux

sudo apt install protobuf-compiler

Mac

brew install protoc

Then run the build command:

protoc -I protos/ protos/currency.proto --go_out=plugins=grpc:protos/currency

or

make protos

Running the application

As this is a POC, all ports and configurations are hardcoded the app will run on port :9098

go run main.go

With grpcurl installed we can test our server

List Services

grpcurl --plaintext localhost:9092 list
Currency
grpc.reflection.v1alpha.ServerReflection

List Methods

grpcurl --plaintext localhost:9098 list Currency        
Currency.GetRate

Method detail for GetRate

grpcurl --plaintext localhost:9098 describe Currency.GetRate
Currency.GetRate is a method:
rpc GetRate ( .RateRequest ) returns ( .RateResponse );

RateRequest detail

grpcurl --plaintext localhost:9098 describe .RateRequest    
RateRequest is a message:
message RateRequest {
  string Base = 1;
  string Destination = 2;
}

Execute a request

grpcurl --plaintext -d '{"Base": "BR", "Destination": "USD"}' localhost:9098 Currency/GetRate
{
  "rate": 5.37
}

{ "Base" : "BRL", "Destination" : "USD" }

{ "Base" : "BRL", "Destination" : "EUR" }

grpcurl --plaintext -d @ localhost:9098 Currency/SubscribeRates

grpcurl --plaintext localhost:9098 HealthCheck/Check