Currency Service

A simple example to understand gRPC in golang!

Directory Structure

.
├── currency.proto
├── main.go
├── Makefile
├── protos
│   ├── currency_grpc.pb.go
│   └── currency.pb.go
├── README.md
└── server
    └── currency.go

Testing

To test the system install grpccurl which is a command line tool which can interact with gRPC API's

Link to the repo is here!

go install github.com/fullstorydev/grpcurl/cmd/grpcurl

Run the server

• Command: go run main.go

List Services

• Command: grpcurl --plaintext localhost:8080 list
• Output:

  Currency
  grpc.reflection.v1alpha.ServerReflection
  

List Methods

• Command: grpcurl --plaintext localhost:8080 list Currency
• Output: Currency.GetRate

Method detail for GetRate

• Command: grpcurl --plaintext localhost:8080 describe Currency.GetRate
• Output:

  Currency.GetRate is a method:
  rpc GetRate ( .RateRequest ) returns ( .RateResponse );
  

RateRequest detail

• Command: grpcurl --plaintext localhost:8080 describe .RateRequest
• Output:

  RateRequest is a message:
  message RateRequest {
      string Base = 1;
      string Destination = 2;
  }
  

RateResponse detail

• Command: grpcurl --plaintext localhost:8080 describe .RateResponse
• Output:

  RateResponse is a message:
  message RateResponse {
      float rate = 1;
  }
  

Execute a request

• Command: grpcurl --plaintext -d '{"Base":"USD","Destination":"INR"}' localhost:8080 Currency.GetRate
• Output:

  {
      "rate": 0.5
  }