查询出口 IP 的小服务

ip.go

package main

import (
	"encoding/json"
	"fmt"
	"log"
	"net"
	"net/http"
	"sync"
	"time"
)

type httpResp struct {
	IP        string
	Headers   []string
	Timestamp int64
}

func httpIP() {
	var port = "10080"

	http.HandleFunc("/", func(w http.ResponseWriter, req *http.Request) {
		log.Println("HTTP request from " + req.RemoteAddr)
		resp := new(httpResp)
		resp.IP = req.RemoteAddr
		for name, headers := range req.Header {
			for _, h := range headers {
				resp.Headers = append(resp.Headers, fmt.Sprintf("%v: %v", name, h))
			}
		}
		resp.Timestamp = time.Now().Unix()
		jsonData, _ := json.Marshal(resp)
		w.Write(jsonData)
	})

	log.Println("Listening on " + port)
	if err := http.ListenAndServe(":"+port, nil); err != nil {
		log.Fatal("Error listening:", err)
	}
}

func socketIP() {
	var l net.Listener
	var err error
	var port = "10088"
	l, err = net.Listen("tcp", ":"+port)
	if err != nil {
		log.Fatal("Error listening:", err)
	}
	defer l.Close()
	log.Println("Listening on " + port)
	for {
		conn, err := l.Accept()
		if err != nil {
			log.Fatal("Error accepting: ", err)
		}

		log.Printf("Received message from %s\n", conn.RemoteAddr())
		go func(conn net.Conn) {
			defer conn.Close()
			conn.Write([]byte(conn.RemoteAddr().String()))
		}(conn)
	}
}

func main() {
	var wg sync.WaitGroup

	wg.Add(1)
	go func() {
		defer wg.Done()
		httpIP()
	}()

	wg.Add(1)
	go func() {
		defer wg.Done()
		socketIP()
	}()

	wg.Wait()
}

ip.service

#path:/lib/systemd/system/
[Unit]
Description=
After=network.target syslog.target
Wants=network.target

[Service]
Type=simple
ExecStart=/opt/ip/ip
Restart=always
RestartSec=20s
#KillSignal=SIGQUIT
#TimeoutStopSec=5
KillMode=process
PrivateTmp=true
StandardOutput=file://opt/ip/systemctl.log
StandardError=inherit

[Install]
WantedBy=multi-user.target