Make hupper watch for proxy changes too

Signed-off-by: Dave Tucker <dt@docker.com>

alpine/packages/hupper/etc/init.d/hupper

@@ -13,16 +13,18 @@ start()
 
 	PIDFILE=/run/hupper.pid
 	DOCKERPIDFILE=/run/docker.pid
-	WATCH=$(mobyconfig watch /etc/docker/daemon.json)
+	WATCH_CONFIG=$(mobyconfig watch /etc/docker/daemon.json)
+	WATCH_PROXY=$(mobyconfig watch proxy)
 
-	[ -z "${WATCH}" ] && exit 1
+	[ -z "${WATCH_CONFIG}" ] && exit 1
+	[ -z "${WATCH_PROXY}" ] && exit 1
 
 	start-stop-daemon --start --quiet \
 		--background \
 		--exec /bin/hupper \
 		--make-pidfile --pidfile ${PIDFILE} \
 		-- -pidfile ${PIDFILE} -huppidfile ${DOCKERPIDFILE} \
-		   -path ${WATCH}
+		   -path ${WATCH_CONFIG} -path ${WATCH_PROXY}
 
 	eend $? "Failed to start hupper"
 }

alpine/packages/hupper/main.go

@@ -2,23 +2,36 @@ package main
 
 import (
 	"flag"
+	"fmt"
 	"io"
 	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
 	"strconv"
+	"sync"
 	"syscall"
 )
 
 var (
-	path       string
+	paths      stringSlice
 	huppidfile string
 	pidfile    string
 )
 
+type stringSlice []string
+
+func (s *stringSlice) String() string {
+	return fmt.Sprintf("%s", *s)
+}
+
+func (s *stringSlice) Set(value string) error {
+	*s = append(*s, value)
+	return nil
+}
+
 func init() {
-	flag.StringVar(&path, "path", "", "path of the file to watch")
+	flag.Var(&paths, "path", "paths of the files to watch")
 	flag.StringVar(&huppidfile, "huppidfile", "", "pidfile for process to signal")
 	flag.StringVar(&pidfile, "pidfile", "", "my pidfile")
 }
@@ -27,7 +40,7 @@ func main() {
 	log.SetFlags(0)
 	flag.Parse()
 
-	if path == "" {
+	if len(paths) < 1 {
 		log.Fatal("watch path not set")
 	}
 
@@ -41,6 +54,10 @@ func main() {
 		_ = ioutil.WriteFile(pidfile, pidbytes, 0644)
 	}
 
+	var wg sync.WaitGroup
+	wg.Add(len(paths))
+
+	for _, path := range paths {
 		watch, err := os.Open(path)
 		if err != nil {
 			log.Fatalln("Failed to open file", path, err)
@@ -52,6 +69,8 @@ func main() {
 		if err != nil && err != io.EOF {
 			log.Fatalln("Error reading watch file", err)
 		}
+
+		go func() {
 			for {
 				_, err := watch.Read(buf)
 				if err != nil && err != io.EOF {
@@ -64,6 +83,7 @@ func main() {
 				// however at present we cannot check changes, and most do
 				restart := true
 				if restart {
+					log.Println("Restarting docker")
 					cmd := exec.Command("service", "docker", "restart")
 					// not much we can do if it does not restart
 					_ = cmd.Run()
@@ -80,4 +100,7 @@ func main() {
 					syscall.Kill(pid, syscall.SIGHUP)
 				}
 			}
+		}()
+	}
+	wg.Wait()
 }