pingmeplz

ping.go

package main

import (
	"fmt"
	logpkg "log"
	"log/syslog"
	"net"
	"net/http"
	"os"
	"os/exec"
	"syscall"
)

const (
	waitSeconds = "3"
	pingCount   = "5"
)

var log *logpkg.Logger

func init() {
	var err error
	log, err = syslog.NewLogger(syslog.LOG_INFO, logpkg.LstdFlags)
	if err != nil {
		log = logpkg.New(os.Stderr, "", logpkg.LstdFlags)
		log.Println("syslog.NewLogger:", err.Error())
	}
	log.Println("init.")
}

func main() {
	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
		log.Printf("%v => %v", r.RemoteAddr, r.URL.String())
		host, _, err := net.SplitHostPort(r.RemoteAddr)
		if err != nil {
			http.Error(w, fmt.Sprintf("RemoteAddr %v: %v", r.RemoteAddr, err), http.StatusBadRequest)
			return
		}

		cmd := exec.Command("ping", "-w", waitSeconds, "-c", pingCount, host)
		out, err := cmd.CombinedOutput()
		if err == nil {
			log.Println("Unexected nil error from exec.Command")
			http.Error(w, "oops", http.StatusInternalServerError)
			return
		}

		if e, ok := err.(*exec.ExitError); ok {
			status := e.Sys().(syscall.WaitStatus).ExitStatus()
			log.Printf("%v : exit status: %d", string(out), status)
			fmt.Fprintf(w, "%v\nexit status: %d\n", string(out), status)
			return
		}

		log.Println("exec CombinedOutput failure:", err)
		http.Error(w, err.Error(), http.StatusInternalServerError)
	})
	log.Fatal(http.ListenAndServe(":8080", nil))
}