bull

README

Bull(公牛)微服务框架

背景

• 从2018年开始，本人一直基于go-micro做微服务开发。
• go-micro是一个不错的微服务框架，但是对我个人而言go-micro太过于臃肿，我并不需要那么多功能。
• 在2021年牛年之际，我打算开发一个精简版的微服务框架。
• 由于2021年是牛年所以就将框架的名称命名为bull即公牛的意思。

简介

Bull是一款基于GO语言的极简微服务框架。

使用GRPC作为RPC协议，使用ETCD作为注册中心。

框架目前已经实现了服务注册、服务发现（客户端轮训）功能。

计划实现：API Gateway、配置中心、服务监控等功能。

整体架构

使用说明

安装etcd

https://github.com/etcd-io/etcd/releases

获取bull框架

go get github.com/w3liu/bull

定义proto协议

syntax = "proto3";

package person;

service Person {
  rpc SayHello(SayHelloRequest) returns (SayHelloResponse) {}
}

message SayHelloRequest {
  string name = 1;
}

message SayHelloResponse {
  string msg = 2;
}

生成grpc代码

protoc --proto_path=. --go_out=plugins=grpc:. *.proto

服务端代码

package main

import (
	"github.com/w3liu/bull"
	"github.com/w3liu/bull/examples/handler"
	pb "github.com/w3liu/bull/examples/proto"
	"github.com/w3liu/bull/registry"
	"google.golang.org/grpc"
)

func main() {
	r := registry.NewRegistry(registry.Addrs([]string{"127.0.0.1:2379"}...))
	service := bull.NewService(
		bull.Registry(r),
	)
	server := service.Server()
	grpcServer, ok := server.Instance().(*grpc.Server)
	if !ok {
		panic("not grpc server")
	}
	pb.RegisterPersonServer(grpcServer, &handler.Person{Name: "Foo"})
	err := service.Run()
	if err != nil {
		panic(err)
	}
}

客户端代码

package main

import (
	"context"
	"fmt"
	"github.com/w3liu/bull/client"
	pb "github.com/w3liu/bull/examples/proto"
	"github.com/w3liu/bull/registry"
	"google.golang.org/grpc"
	"time"
)

func main() {
	r := registry.NewRegistry(registry.Addrs([]string{"127.0.0.1:2379"}...))
	cli := client.NewClient(
		client.Registry(r),
		client.Service("hello.svc"))

	conn, ok := cli.Instance().(*grpc.ClientConn)
	if !ok {
		panic("not grpc client conn instance")
	}
	personClient := pb.NewPersonClient(conn)

	for i := 0; i < 10; i++ {
		ctx, _ := context.WithTimeout(context.TODO(), time.Second*5)
		rsp, err := personClient.SayHello(ctx, &pb.SayHelloRequest{
			Name: "Bar",
		})
		if err != nil {
			panic(err)
		}
		fmt.Println(rsp)
	}
}

测试用例

• 打开service_test.go文件，分别运行TestService1 TestService2 TestService3 会启动三个后端服务
• 若启动成功，查看./log/info.log，会有如下日志：

2021-03-12 17:17:48.854	INFO	bull/service.go:96	Starting [service] hello.svc_0
2021-03-12 17:17:48.861	INFO	server/grpc_server.go:101	Server [grpc] Listening on [::]:50743
2021-03-12 17:17:48.871	INFO	server/grpc_server.go:294	Registry [etcd] Registering node: hello.svc_0-10b9a275-0b29-4394-b11e-bbb517d1e7fb
2021-03-12 17:17:48.873	INFO	registry/etcd_registry.go:223	Registering hello.svc_0 id hello.svc_0-10b9a275-0b29-4394-b11e-bbb517d1e7fb with lease cluster_id:14841639068965178418 member_id:10276657743932975437 revision:22 raft_term:4  and leaseID 7587853048034846508 and ttl 30s

• 运行TestClient，查看调试窗口，会有如下输出：

API server listening at: 127.0.0.1:50117
=== RUN   TestClient
msg:"Foo1 say hello to Bar" 
msg:"Foo3 say hello to Bar" 
msg:"Foo1 say hello to Bar" 
msg:"Foo3 say hello to Bar" 
msg:"Foo1 say hello to Bar" 
msg:"Foo3 say hello to Bar" 
msg:"Foo1 say hello to Bar" 
msg:"Foo3 say hello to Bar" 
msg:"Foo1 say hello to Bar" 
···

Documentation

Index

• type Option
  • func Client(c client.Client) Option
  • func Context(ctx context.Context) Option
  • func Registry(r registry.Registry) Option
  • func Server(s server.Server) Option
• type Options
• type Service
  • func NewService(opts ...Option) Service

Types

type Option

type Option func(*Options)

func Client

func Client(c client.Client) Option

Client to be used for service

func Context

func Context(ctx context.Context) Option

Context specifies a context for the service. Can be used to signal shutdown of the service and for extra option values.

func Registry

func Registry(r registry.Registry) Option

Registry sets the registry for the service and the underlying components

func Server

func Server(s server.Server) Option

Server to be used for service

type Options

type Options struct {
	Client   client.Client
	Server   server.Server
	Registry registry.Registry

	// Before and After funcs
	BeforeStart []func() error
	BeforeStop  []func() error
	AfterStart  []func() error
	AfterStop   []func() error

	// Other options for implementations of the interface
	// can be stored in a context
	Context context.Context
}

type Service

type Service interface {
	// The service name
	Name() string
	// Init initialises options
	Init(...Option)
	// Options returns the current options
	Options() Options
	// Client is used to call services
	Client() client.Client
	// Server is for handling requests and events
	Server() server.Server
	// Run the service
	Run() error
	// The service implementation
	String() string
}

func NewService

func NewService(opts ...Option) Service