supervisor.go

package main

import (
	"flag"
	"fmt"
	"io/ioutil"
	"log"
	"os"
	"os/signal"
	"strconv"
	"syscall"
)

var (
	daemon      bool
	children    []*os.Process
	childrenPID []int
	extensions  = []string{
		"phoenix",
		"konnectd",
	}
	command string

	kill  string // extension to kill
	start string // extension to start
)

func init() {
	flag.BoolVar(&daemon, "d", false, "runs as a daemon")
	flag.StringVar(&command, "cmd", "", "commamnd to run as a fork")
	flag.StringVar(&kill, "k", "", "extension to kill")
	flag.StringVar(&start, "s", "", "extension to start")

	flag.Parse()
}

var (
	childSig  = make(chan os.Signal)
	parentSig = make(chan os.Signal)
)

func main() {

	// kill an extension by name
	if len(kill) > 0 {
		contents, err := ioutil.ReadFile(kill + ".pid")
		if err != nil {
			log.Fatal(err)
		}

		PID, err := strconv.Atoi(string(contents))
		if err != nil {
			log.Fatal(err)
		}

		if err = syscall.Kill(PID, syscall.SIGKILL); err != nil {
			log.Fatal(err)
		}

		fmt.Printf("PID: %v killed", PID)

		if err = os.Remove(kill + ".pid"); err != nil {
			log.Fatal(err)
		}

		return
	}

	// start an extension by name
	if len(start) > 0 {
		proc, err := os.StartProcess("/Users/aunger/go/bin/ocis", []string{"/Users/aunger/go/bin/ocis", start}, &os.ProcAttr{
			Files: []*os.File{
				os.Stdin,
				os.Stdout,
				os.Stderr,
			},
			Sys: &syscall.SysProcAttr{
				Noctty: true,
			},
		})
		if err != nil {
			log.Fatal(err)
		}

		ioutil.WriteFile(start+".pid", []byte(strconv.Itoa(proc.Pid)), 0644)
	}

	for _, v := range extensions {
		proc, err := os.StartProcess("/Users/aunger/go/bin/ocis", []string{"/Users/aunger/go/bin/ocis", v}, &os.ProcAttr{
			Files: []*os.File{
				os.Stdin,
				os.Stdout,
				os.Stderr,
			},
		})
		if err != nil {
			log.Fatal(err)
		}

		children = append(children, proc)

		ioutil.WriteFile(v+".pid", []byte(strconv.Itoa(proc.Pid)), 0644)
	}

	signal.Notify(parentSig, os.Interrupt, os.Kill)
	signal.Notify(childSig, os.Interrupt, os.Kill)

	for {
		select {
		case <-parentSig:
			// TODO range over pid files
			for c := range children {
				syscall.Kill(c, syscall.SIGKILL)
			}
			return
		case <-childSig:
			fmt.Println("deaded x.x")
		}

	}
}