added dependency github.com/sevlyar/go-daemon

vendor/github.com/sevlyar/go-daemon/signal.go

@@ -0,0 +1,59 @@
+package daemon
+
+import (
+	"errors"
+	"os"
+	"os/signal"
+	"syscall"
+)
+
+// ErrStop should be returned signal handler function
+// for termination of handling signals.
+var ErrStop = errors.New("stop serve signals")
+
+// SignalHandlerFunc is the interface for signal handler functions.
+type SignalHandlerFunc func(sig os.Signal) (err error)
+
+// func SetSigHandler sets handler for the given signals.
+// SIGTERM has the default handler, he returns ErrStop.
+func SetSigHandler(handler SignalHandlerFunc, signals ...os.Signal) {
+	for _, sig := range signals {
+		handlers[sig] = handler
+	}
+}
+
+// func ServeSignals calls handlers for system signals.
+func ServeSignals() (err error) {
+	signals := make([]os.Signal, 0, len(handlers))
+	for sig, _ := range handlers {
+		signals = append(signals, sig)
+	}
+
+	ch := make(chan os.Signal, 8)
+	signal.Notify(ch, signals...)
+
+	for sig := range ch {
+		err = handlers[sig](sig)
+		if err != nil {
+			break
+		}
+	}
+
+	signal.Stop(ch)
+
+	if err == ErrStop {
+		err = nil
+	}
+
+	return
+}
+
+var handlers = make(map[os.Signal]SignalHandlerFunc)
+
+func init() {
+	handlers[syscall.SIGTERM] = sigtermDefaultHandler
+}
+
+func sigtermDefaultHandler(sig os.Signal) error {
+	return ErrStop
+}