add signal handling boilerblate

.gitignore

@@ -5,3 +5,4 @@
 *.coverprofile
 *exportable-fuzz.zip
 go-i2p
+*.exe

lib/router/router.go

@@ -1,14 +1,17 @@
 package router
 
 import (
+	log "github.com/Sirupsen/logrus"
 	"github.com/hkparker/go-i2p/lib/config"
 	"github.com/hkparker/go-i2p/lib/netdb"
+	"time"
 )
 
 // i2p router type
 type Router struct {
-	cfg *config.RouterConfig
-	ndb netdb.StdNetDB
+	cfg       *config.RouterConfig
+	ndb       netdb.StdNetDB
+	closeChnl chan bool
 }
 
 // create router with default configuration
@@ -22,9 +25,22 @@ func CreateRouter() (r *Router, err error) {
 func FromConfig(c *config.RouterConfig) (r *Router, err error) {
 	r = new(Router)
 	r.cfg = c
+	r.closeChnl = make(chan bool)
 	return
 }
 
+func (r *Router) Wait() {
+	<-r.closeChnl
+}
+
+func (r *Router) Stop() {
+	r.closeChnl <- true
+}
+
+func (r *Router) Close() error {
+	return nil
+}
+
 // run i2p router mainloop
 func (r *Router) Run() {
 	r.ndb = netdb.StdNetDB(r.cfg.NetDb.Path)
@@ -32,5 +48,17 @@ func (r *Router) Run() {
 	err := r.ndb.Ensure()
 	if err == nil {
 		// netdb ready
+		log.WithFields(log.Fields{
+			"at": "(Router) Run",
+		}).Info("Router ready")
+		for err == nil {
+			time.Sleep(time.Second)
+		}
+	} else {
+		// netdb failed
+		log.WithFields(log.Fields{
+			"at":     "(Router) Run",
+			"reason": err.Error(),
+		}).Error("Netdb Startup failed")
 	}
 }

lib/util/closeables.go

@@ -0,0 +1,16 @@
+package util
+
+import "io"
+
+var closeOnExit []io.Closer
+
+func RegisterCloser(c io.Closer) {
+	closeOnExit = append(closeOnExit, c)
+}
+
+func CloseAll() {
+	for idx := range closeOnExit {
+		closeOnExit[idx].Close()
+	}
+	closeOnExit = nil
+}

lib/util/signals/signals.go

@@ -0,0 +1,33 @@
+package signals
+
+import (
+	"os"
+)
+
+var sigChan = make(chan os.Signal)
+
+type Handler func()
+
+var reloaders []Handler
+
+func RegisterReloadHandler(f Handler) {
+	reloaders = append(reloaders, f)
+}
+
+func handleReload() {
+	for idx := range reloaders {
+		reloaders[idx]()
+	}
+}
+
+var interrupters []Handler
+
+func RegisterInterruptHandler(f Handler) {
+	interrupters = append(interrupters, f)
+}
+
+func handleInterrupted() {
+	for idx := range interrupters {
+		interrupters[idx]()
+	}
+}

lib/util/signals/unix.go

@@ -0,0 +1,30 @@
+// +build !windows
+
+package signals
+
+import (
+	"os/signal"
+	"syscall"
+)
+
+func init() {
+	signal.Notify(sigChan, syscall.SIGINT, syscall.SIGTERM, syscall.SIGHUP)
+}
+
+func Handle() {
+	for {
+		sig, ok := <-sigChan
+		if !ok {
+			// closed channel
+			return
+		}
+		if sig == syscall.SIGHUP {
+			handleReload()
+		} else if sig == syscall.SIGINT || sig == syscall.SIGTERM {
+			handleInterrupted()
+		} else {
+			// wtf?
+		}
+	}
+
+}

lib/util/signals/windows.go

@@ -0,0 +1,28 @@
+// +build windows
+
+package signals
+
+import (
+	"os"
+	"os/signal"
+)
+
+func init() {
+	signal.Notify(sigChan, os.Interrupt)
+}
+
+func Handle() {
+	for {
+		sig, ok := <-sigChan
+		if !ok {
+			// closed channel
+			return
+		}
+		if sig == os.Interrupt {
+			handleInterrupted()
+		} else {
+			// wtf?
+		}
+	}
+
+}

main.go

@@ -3,16 +3,26 @@ package main
 import (
 	log "github.com/Sirupsen/logrus"
 	"github.com/hkparker/go-i2p/lib/router"
+	"github.com/hkparker/go-i2p/lib/util/signals"
 )
 
 func main() {
-
+	go signals.Handle()
 	log.Info("parsing i2p router configuration")
 
 	log.Info("starting up i2p router")
 	r, err := router.CreateRouter()
 	if err == nil {
-		r.Run()
+		signals.RegisterReloadHandler(func() {
+			// TODO: reload config
+		})
+		signals.RegisterInterruptHandler(func() {
+			// TODO: graceful shutdown
+			r.Stop()
+		})
+		go r.Run()
+		defer r.Close()
+		r.Wait()
 	} else {
 		log.Errorf("failed to create i2p router: %s", err)
 	}