grpc(二)

使用grpc

1 服务定义

syntax = "proto3";
package hello;

service ProductInfo {
    rpc say(HelloReq) returns (HelloResp);
}

message HelloReq {
    string id = 1;
}

message HelloResp {
    string value = 1;
}

2 实现

1. gRPC运行时接口编解码支持库
   go get -u github.com/golang/protobuf/proto

2. 从 Proto文件(gRPC接口描述文件) 生成 go文件 的编译器插件
   go get -u github.com/golang/protobuf/protoc-gen-go

3. 获取go的gRPC包
   go get google.golang.org/grpc

4. 生成代码

protoc --go_out=. *.proto
protoc --go_out=plugins=grpc:. ./hello/hello.proto

也可以知道其他目录
protoc --go_out=plugins=grpc:./msg2 ./hello/hello.proto

protoc -I ecommerce ecommerce/product_info.proto --go_out=plugins=grpc:./server/ecommerce

//option go_package="./;ecommerce";

—I 指定搜索目录，如果没有指定 –I 参数，则在当前目录进行搜索
--go_out=plugins=grpc:helloworld是输出目录

option go_package =“go/src/microtest/proto”;

5. 为啥要定义reflection.Register(serv)

客户端可以看到服务端的信息

grpcurl调用服务

grpcurl -plaintext localhost:8741 list

grpcurl -plaintext localhost:8741 describe Greeter

grpcurl -plaintext localhost:8741 describe grpc.reflection.v1alpha.ServerReflection

grpcurl -plaintext localhost:8741 describe Greeter.SayHello

grpcurl -plaintext -d '{"name": "gopher"}' localhost:8741 Greeter.SayHello
{
 "message": "hello gopher"
}


grpcurl -plaintext -d @ localhost:8741 Greeter.SayHello
{"name": "gopher"}

3 构建和运行

 syntax = "proto3";

package ecommerce;

service ProductInfo {
    rpc addProduct(Product) returns (ProductID);
    rpc getProduct(ProductID) returns (Product);
}

message Product {
    string id = 1;
    string name = 2;
    string description = 3;
    float price = 4;
}

message ProductID {
    string value = 1;
}

protoc -I ecommerce ecommerce/product_info.proto --go_out=plugins=grpc:./server/ecommerce
protoc -I ecommerce ecommerce/product_info.proto --go_out=plugins=grpc:./client/ecommerce

运行serveice

server通用的代码

lis, err := net.Listen("tcp", port)
	if err != nil {
		log.Fatalf("failed to listen: %v", err)
	}
	s := grpc.NewServer()
	pb.RegisterProductInfoServer(s, &server{})
	if err := s.Serve(lis); err != nil {
		log.Fatalf("failed to serve: %v", err)
	}

client通用的代码

// Set up a connection to the server.
	conn, err := grpc.Dial(address, grpc.WithInsecure())
	if err != nil {
		log.Fatalf("did not connect: %v", err)
	}
	defer conn.Close()
	c := pb.NewProductInfoClient(conn)

	// Contact the server and print out its response.
	name := "Apple iPhone 11"
	description := "Meet Apple iPhone 11. All-new dual-camera system with Ultra Wide and Night mode."
	price := float32(699.00)
	ctx, cancel := context.WithTimeout(context.Background(), time.Second)
	defer cancel()
	r, err := c.AddProduct(ctx, &pb.Product{Name: name, Description: description, Price: price})
	if err != nil {
		log.Fatalf("Could not add product: %v", err)
	}
	log.Printf("Product ID: %s added successfully", r.Value)

	product, err := c.GetProduct(ctx, &pb.ProductID{Value: r.Value})
	if err != nil {
		log.Fatalf("Could not get product: %v", err)
	}
	log.Printf("Product: %v", product.String())