From c28a87cbc174dba89121b1c0708f9eb487da3ef8 Mon Sep 17 00:00:00 2001
From: Michael Crosby <crosbymichael@gmail.com>
Date: Mon, 21 Mar 2016 12:54:05 -0700
Subject: [PATCH] Handle term signals gracefully

Signed-off-by: Michael Crosby <crosbymichael@gmail.com>
---
 containerd/main.go         | 45 ++++++++++++++++++++++++++++++++------
 containerd/main_linux.go   | 14 ------------
 containerd/main_windows.go | 29 ------------------------
 3 files changed, 38 insertions(+), 50 deletions(-)
 delete mode 100644 containerd/main_windows.go

diff --git a/containerd/main.go b/containerd/main.go
index d8d54e8..74f7048 100644
--- a/containerd/main.go
+++ b/containerd/main.go
@@ -4,7 +4,9 @@ import (
 	"fmt"
 	"net"
 	"os"
+	"os/signal"
 	"sync"
+	"syscall"
 	"time"
 
 	"google.golang.org/grpc"
@@ -14,6 +16,7 @@ import (
 	"github.com/docker/containerd"
 	"github.com/docker/containerd/api/grpc/server"
 	"github.com/docker/containerd/api/grpc/types"
+	"github.com/docker/containerd/osutils"
 	"github.com/docker/containerd/supervisor"
 )
 
@@ -80,7 +83,11 @@ func main() {
 func daemon(address, stateDir string, concurrency int, runtimeName string) error {
 	// setup a standard reaper so that we don't leave any zombies if we are still alive
 	// this is just good practice because we are spawning new processes
-	go reapProcesses()
+	s := make(chan os.Signal, 2048)
+	signal.Notify(s, syscall.SIGCHLD, syscall.SIGTERM, syscall.SIGINT)
+	if err := osutils.SetSubreaper(1); err != nil {
+		logrus.WithField("error", err).Error("containerd: set subpreaper")
+	}
 	sv, err := supervisor.New(stateDir, runtimeName)
 	if err != nil {
 		return err
@@ -94,17 +101,41 @@ func daemon(address, stateDir string, concurrency int, runtimeName string) error
 	if err := sv.Start(); err != nil {
 		return err
 	}
-	if err := os.RemoveAll(address); err != nil {
-		return err
-	}
-	l, err := net.Listen(defaultListenType, address)
+	server, err := startServer(address, sv)
 	if err != nil {
 		return err
 	}
+	for ss := range s {
+		switch ss {
+		case syscall.SIGCHLD:
+			if _, err := osutils.Reap(); err != nil {
+				logrus.WithField("error", err).Warn("containerd: reap child processes")
+			}
+		default:
+			server.Stop()
+			os.Exit(0)
+		}
+	}
+	return nil
+}
+
+func startServer(address string, sv *supervisor.Supervisor) (*grpc.Server, error) {
+	if err := os.RemoveAll(address); err != nil {
+		return nil, err
+	}
+	l, err := net.Listen(defaultListenType, address)
+	if err != nil {
+		return nil, err
+	}
 	s := grpc.NewServer()
 	types.RegisterAPIServer(s, server.NewServer(sv))
-	logrus.Debugf("containerd: grpc api on %s", address)
-	return s.Serve(l)
+	go func() {
+		logrus.Debugf("containerd: grpc api on %s", address)
+		if err := s.Serve(l); err != nil {
+			logrus.WithField("error", err).Fatal("containerd: serve grpc")
+		}
+	}()
+	return s, nil
 }
 
 // getDefaultID returns the hostname for the instance host
diff --git a/containerd/main_linux.go b/containerd/main_linux.go
index 2abf327..49fc790 100644
--- a/containerd/main_linux.go
+++ b/containerd/main_linux.go
@@ -4,7 +4,6 @@ import (
 	"log"
 	"net"
 	"os"
-	"os/signal"
 	"runtime"
 	"syscall"
 	"time"
@@ -62,19 +61,6 @@ func checkLimits() error {
 	return nil
 }
 
-func reapProcesses() {
-	s := make(chan os.Signal, 2048)
-	signal.Notify(s, syscall.SIGCHLD)
-	if err := osutils.SetSubreaper(1); err != nil {
-		logrus.WithField("error", err).Error("containerd: set subpreaper")
-	}
-	for range s {
-		if _, err := osutils.Reap(); err != nil {
-			logrus.WithField("error", err).Error("containerd: reap child processes")
-		}
-	}
-}
-
 func processMetrics() {
 	var (
 		g    = metrics.NewGauge()
diff --git a/containerd/main_windows.go b/containerd/main_windows.go
deleted file mode 100644
index 06c5750..0000000
--- a/containerd/main_windows.go
+++ /dev/null
@@ -1,29 +0,0 @@
-package main
-
-import (
-	"os"
-
-	"github.com/codegangsta/cli"
-)
-
-var defaultStateDir = os.Getenv("PROGRAMDATA") + `\docker\containerd`
-
-const (
-	defaultListenType   = "tcp"
-	defaultGRPCEndpoint = "localhost:2377"
-)
-
-func appendPlatformFlags() {
-}
-
-// TODO Windows: May be able to factor out entirely
-func checkLimits() error {
-	return nil
-}
-
-// No idea how to implement this on Windows.
-func reapProcesses() {
-}
-
-func setAppBefore(app *cli.App) {
-}