package mainimport ( "fmt" "strconv" "time" "math/rand" "net" "flag" "strings" "encoding/json")// 节点数据信息type NodeInfo struct { // 节点ID，通过随机数生成 NodeId int `json:"nodeId"` // 节点IP地址 NodeIpAddr string `json:"nodeIpAddr"` // 节点端口 Port string `json: "port"`}// 将节点数据信息格式化输出//NodeInfo:{nodeId: 89423,nodeIpAddr: 127.0.0.1/8,port: 8001}func (node *NodeInfo) String() string { return "NodeInfo:{ nodeId:" + strconv.Itoa(node.NodeId) + ",nodeIpAddr:" + node.NodeIpAddr + ",port:" + node.Port + "}"}/* 添加一个节点到集群的一个请求或者响应的标准格式 */type AddToClusterMessage struct { // 源节点 Source NodeInfo `json:"source"` // 目的节点 Dest NodeInfo `json:"dest"` // 两个节点连接时发送的消息 Message string `json:"message"`}/* Request/Response 信息格式化输出 */func (req AddToClusterMessage) String() string { return "AddToClusterMessage:{/n source:" + req.Source.String() + ",/n dest: " + req.Dest.String() + ",/n message:" + req.Message + " }"}// cat vi go// rmfunc main() { // 解析命令行参数 makeMasterOnError := flag.Bool("makeMasterOnError", false, "如果IP地址没有连接到集群中，我们将其作为Master节点.") clusterip := flag.String("clusterip", "127.0.0.1:8001", "任何的节点连接都连接这个IP") myport := flag.String("myport", "8001", "ip address to run this node on. default is 8001.") flag.Parse() //解析 fmt.Println(*makeMasterOnError) fmt.Println(*clusterip) fmt.Println(*myport) /* 为节点生成ID */ rand.Seed(time.Now().UTC().UnixNano()) //种子 myid := rand.Intn(99999999) // 随机 //fmt.Println(myid) // 获取IP地址 myIp,_ := net.InterfaceAddrs() fmt.Println(myIp[0]) // 创建NodeInfo结构体对象 me := NodeInfo{NodeId: myid, NodeIpAddr: myIp[0].String(), Port: *myport} // 输出结构体数据信息 fmt.Println(me.String()) dest := NodeInfo{ NodeId: -1, NodeIpAddr: strings.Split(*clusterip, ":")[0], Port: strings.Split(*clusterip, ":")[1]} /* 尝试连接到集群，在已连接的情况下并且向集群发送请求 */ ableToConnect := connectToCluster(me, dest) /* * 监听其他节点将要加入到集群的请求 */ if ableToConnect || (!ableToConnect && *makeMasterOnError) { if *makeMasterOnError {fmt.Println("Will start this node as master.")} listenOnPort(me) } else { fmt.Println("Quitting system. Set makeMasterOnError flag to make the node master.", myid) }}/* * 这是发送请求时格式化json包有用的工具 * 这是非常重要的，如果不经过数据格式化，你最终发送的将是空白消息 */func getAddToClusterMessage(source NodeInfo, dest NodeInfo, message string) (AddToClusterMessage){ return AddToClusterMessage{ Source: NodeInfo{ NodeId: source.NodeId, NodeIpAddr: source.NodeIpAddr, Port: source.Port, }, Dest: NodeInfo{ NodeId: dest.NodeId, NodeIpAddr: dest.NodeIpAddr, Port: dest.Port, }, Message: message, }}func connectToCluster(me NodeInfo, dest NodeInfo) (bool){ /* 连接到socket的相关细节信息 */ connOut, err := net.DialTimeout("tcp", dest.NodeIpAddr + ":" + dest.Port, time.Duration(10) * time.Second) if err != nil { if _, ok := err.(net.Error); ok { fmt.Println("未连接到集群.", me.NodeId) return false } } else { fmt.Println("连接到集群. 发送消息到节点.") text := "Hi nody.. 请添加我到集群.." requestMessage := getAddToClusterMessage(me, dest, text) json.NewEncoder(connOut).Encode(&requestMessage) decoder := json.NewDecoder(connOut) var responseMessage AddToClusterMessage decoder.Decode(&responseMessage) fmt.Println("得到数据响应:/n" + responseMessage.String()) return true } return false}func listenOnPort(me NodeInfo){ /* 监听即将到来的消息 */ ln, _ := net.Listen("tcp", fmt.Sprint(":" + me.Port)) /* 接受连接 */ for { connIn, err := ln.Accept() if err != nil { if _, ok := err.(net.Error); ok { fmt.Println("Error received while listening.", me.NodeId) } } else { var requestMessage AddToClusterMessage json.NewDecoder(connIn).Decode(&requestMessage) fmt.Println("Got request:/n" + requestMessage.String()) text := "Sure buddy.. too easy.." responseMessage := getAddToClusterMessage(me, requestMessage.Source, text) json.NewEncoder(connIn).Encode(&responseMessage) connIn.Close() } }} /Users/liyuechun/goliyuechun:go yuechunli$ go install mainliyuechun:go yuechunli$ mainMy details: NodeInfo:{ nodeId:53163002, nodeIpAddr:127.0.0.1/8, port:8001 }不能连接到集群. 53163002Quitting system. Set makeMasterOnError flag to make the node master. 53163002liyuechun:go yuechunli$ 
