go本地unix socket

common.go

package common

const (
	SocketPath = "/run/test.sock"
)

type Request struct {
	Age int `json:"age"`
}

type Response struct {
	Err string `json:"err"`
}

client.go

package main

import (
	"encoding/json"
	"fmt"
	"net"

	"go-test/common"
)

func main() {
	// 连接服务端
	conn, err := net.Dial("unix", common.SocketPath)
	if err != nil {
		fmt.Printf("connect unix %s failed, err is %v\n", common.SocketPath, err)
		return
	}
	defer conn.Close()

	req := &common.Request{
		Age: 17,
	}
	bytes, err := json.Marshal(req)
	if err != nil {
		fmt.Printf("marshal request failed, err is %v\n", err)
		return
	}

	// 发送请求
	if _, err = conn.Write(bytes); err != nil {
		fmt.Printf("write request failed, err is %v\n", err)
		return
	}

	// 读取响应
	buf := make([]byte, 1024)
	n, err := conn.Read(buf)
	if err != nil {
		fmt.Printf("read response failed, err is %v\n", err)
		return
	}

	resp := &common.Response{}
	if err = json.Unmarshal(buf[:n], resp); err != nil {
		fmt.Printf("json unmarshal response failed, err is %v", err)
		return
	}

	fmt.Printf("read response %s\n", resp.Err)
}

server.go

package main

import (
	"encoding/json"
	"fmt"
	"net"
	"os"

	"go-test/common"
)

func sendResponse(resp *common.Response, conn net.Conn) {
	bytes, err := json.Marshal(resp)
	if err != nil {
		bytes = []byte(err.Error())
	}

	if _, err = conn.Write(bytes); err != nil {
		fmt.Printf("conn write response failed, err is %v", err)
	}
}

func main() {
	os.Remove(common.SocketPath)

	// 创建Unix套接字
	listener, err := net.Listen("unix", common.SocketPath)
	if err != nil {
		fmt.Printf("listen unix socket %s failed, err is %v\n", common.SocketPath, err)
		return
	}
	defer listener.Close()

	// 等待客户端连接
	conn, err := listener.Accept()
	if err != nil {
		fmt.Printf("listener accept failed, err is %v\n", err)
		return
	}
	defer conn.Close()

	// 读取客户端数据并响应
	buf := make([]byte, 1024)
	n, err := conn.Read(buf)
	if err != nil {
		fmt.Printf("read client request data failed, err is %v\n", err)
		return
	}

	req := common.Request{}
	resp := &common.Response{}
	if err := json.Unmarshal(buf[:n], &req); err != nil {
		resp.Err = err.Error()
		sendResponse(resp, conn)
		return
	}

	fmt.Printf("receive age %d from client\n", req.Age)

	resp.Err = "ok"
	sendResponse(resp, conn)
}

go build -o client client/client.go
go build -o server server/server.go

问题：bind: address already in use

在创建Unix套接字之前不能创建这个文件，调用net.Listen函数会自动创建。

os.Remove(common.SocketPath)
os.Create(common.SocketPath)
listener, err := net.Listen("unix", common.SocketPath)