Simple Golang gRPC Client/Server example

First you need to create a proto file with version 3 named as "service1.proto" as below:

syntax="proto3";

package service1;

message SensorReadingRep{
	string readings=1;
}

message SensorReadingsReq{
	string sensorno=1;
}

service Sensor{
	rpc SendReadings(SensorReadingsReq) returns (SensorReadingRep) {}
}

After that you need to compile it into Go file using below command taking into consideration "plugins=grpc:.":

protoc ./service1.proto --go_out=plugins=grpc:.

Then you need to create a gRPC server implemtation by doing the following steps:

|1. Create new empty struct which will be dealt with as a Server for your gRPC connectin:

type server struct{}	

|2. Listen to a TCP port let it be port 32001 using normal Go "net" packge

|3. Create an ew gRPC server usign "grpc.NewServer()" which is defined within "google.golang.org/grpc" Go packge:

s:=grpc.NewServer()

|4. Register server to our custom gRPC service:

pb.RegisterSensorServer(s, &server{})

|5. Serve clients:

s.Serve(ln)

Finally, you need to create a gRPC client implmentation as simple as:

|1. Dial a gRPC connection to our server using "grpc.Dial".

conn,err:= grpc.Dial("localhost:32001", grpc.WithInsecure())
	if err!=nil{
		log.Fatalf("%s\n", err)
	}

|2. Register our client to the custom gRPC service:

c:= pb.NewSensorClient(conn)

|3. Call our custom gRPC method, taking into considertion "context" parameter as per the specs:

r,err:= c.SendReadings(context.Background(), &pb.SensorReadingsReq{Sensorno:"2"})
	if err!=nil{
		log.Fatalf("%s\n",err)
	}

|4. Finally, handle the response!