Golang 微服务教程（一）

// shipper/consignment-service/proto/consignment/consignment.proto

syntax = "proto3";
package go.micro.srv.consignment;

// 货轮微服务
service ShippingService {
    // 托运一批货物
    rpc CreateConsignment (Consignment) returns (Response) {
    }
}

// 货轮承运的一批货物
message Consignment {
    string id = 1;                      // 货物编号
    string description = 2;             // 货物描述
    int32 weight = 3;                   // 货物重量
    repeated Container containers = 4;  // 这批货有哪些集装箱
    string vessel_id = 5;               // 承运的货轮
}

// 单个集装箱
message Container {
    string id = 1;          // 集装箱编号
    string customer_id = 2; // 集装箱所属客户的编号
    string origin = 3;      // 出发地
    string user_id = 4;     // 集装箱所属用户的编号
}

// 托运结果
message Response {
    bool created = 1;			// 托运成功
    Consignment consignment = 2;// 新托运的货物
}

type ShippingServiceClient interface {
	// 托运一批货物
	CreateConsignment(ctx context.Context, in *Consignment, opts ...grpc.CallOption) (*Response, error)
}

type Consignment struct {
	Id           string       `protobuf:"bytes,1,opt,name=id" json:"id,omitempty"`
	Description  string       `protobuf:"bytes,2,opt,name=description" json:"description,omitempty"`
	Weight       int32        `protobuf:"varint,3,opt,name=weight" json:"weight,omitempty"`
	Containers   []*Container `protobuf:"bytes,4,rep,name=containers" json:"containers,omitempty"`
    // ...
}

package main

import (
    // 导如 protoc 自动生成的包
	pb "shippy/consignment-service/proto/consignment"
	"context"
	"net"
	"log"
	"google.golang.org/grpc"
)

const (
	PORT = ":50051"
)

//
// 仓库接口
//
type IRepository interface {
	Create(consignment *pb.Consignment) (*pb.Consignment, error) // 存放新货物
}

//
// 我们存放多批货物的仓库，实现了 IRepository 接口
//
type Repository struct {
	consignments []*pb.Consignment
}

func (repo *Repository) Create(consignment *pb.Consignment) (*pb.Consignment, error) {
	repo.consignments = append(repo.consignments, consignment)
	return consignment, nil
}

func (repo *Repository) GetAll() []*pb.Consignment {
	return repo.consignments
}

//
// 定义微服务
//
type service struct {
	repo Repository
}

//
// service 实现 consignment.pb.go 中的 ShippingServiceServer 接口
// 使 service 作为 gRPC 的服务端
//
// 托运新的货物
func (s *service) CreateConsignment(ctx context.Context, req *pb.Consignment) (*pb.Response, error) {
	// 接收承运的货物
	consignment, err := s.repo.Create(req)
	if err != nil {
		return nil, err
	}
	resp := &pb.Response{Created: true, Consignment: consignment}
	return resp, nil
}

func main() {
	listener, err := net.Listen("tcp", PORT)
	if err != nil {
		log.Fatalf("failed to listen: %v", err)
	}
	log.Printf("listen on: %s\n", PORT)

	server := grpc.NewServer()
	repo := Repository{}

    // 向 rRPC 服务器注册微服务
    // 此时会把我们自己实现的微服务 service 与协议中的 ShippingServiceServer 绑定
	pb.RegisterShippingServiceServer(server, &service{repo})

	if err := server.Serve(listener); err != nil {
		log.Fatalf("failed to serve: %v", err)
	}
}

package main

import (
	pb "shippy/consignment-service/proto/consignment"
	"context"
	"net"
	"log"
	"google.golang.org/grpc"
)

const (
	PORT = ":50051"
)

//
// 仓库接口
//
type IRepository interface {
	Create(consignment *pb.Consignment) (*pb.Consignment, error) // 存放新货物
	GetAll() []*pb.Consignment                                   // 获取仓库中所有的货物
}

//
// 我们存放多批货物的仓库，实现了 IRepository 接口
//
type Repository struct {
	consignments []*pb.Consignment
}

func (repo *Repository) Create(consignment *pb.Consignment) (*pb.Consignment, error) {
	repo.consignments = append(repo.consignments, consignment)
	return consignment, nil
}

func (repo *Repository) GetAll() []*pb.Consignment {
	return repo.consignments
}

//
// 定义微服务
//
type service struct {
	repo Repository
}

//
// 实现 consignment.pb.go 中的 ShippingServiceServer 接口
// 使 service 作为 gRPC 的服务端
//
// 托运新的货物
func (s *service) CreateConsignment(ctx context.Context, req *pb.Consignment) (*pb.Response, error) {
	// 接收承运的货物
	consignment, err := s.repo.Create(req)
	if err != nil {
		return nil, err
	}
	resp := &pb.Response{Created: true, Consignment: consignment}
	return resp, nil
}

// 获取目前所有托运的货物
func (s *service) GetConsignments(ctx context.Context, req *pb.GetRequest) (*pb.Response, error) {
	allConsignments := s.repo.GetAll()
	resp := &pb.Response{Consignments: allConsignments}
	return resp, nil
}

func main() {
	listener, err := net.Listen("tcp", PORT)
	if err != nil {
		log.Fatalf("failed to listen: %v", err)
	}
	log.Printf("listen on: %s\n", PORT)

	server := grpc.NewServer()
	repo := Repository{}
	pb.RegisterShippingServiceServer(server, &service{repo})

	if err := server.Serve(listener); err != nil {
		log.Fatalf("failed to serve: %v", err)
	}
}

func main() {
    ... 

	// 列出目前所有托运的货物
	resp, err = client.GetConsignments(context.Background(), &pb.GetRequest{})
	if err != nil {
		log.Fatalf("failed to list consignments: %v", err)
	}
	for _, c := range resp.Consignments {
		log.Printf("%+v", c)
	}
}