From 9821180548b07546401a17c4d52fde430acfea99 Mon Sep 17 00:00:00 2001
From: Justin Barrick <jbarrick@cloudflare.com>
Date: Thu, 7 Jun 2018 15:50:31 -0700
Subject: [PATCH] Add a restart and stop command to service.

Signed-off-by: justinbarrick <jbarrick@cloudflare.com>
---
 pkg/init/cmd/service/{start.go => cmd.go} | 86 +++++++++++++++++++++--
 pkg/init/cmd/service/main.go              | 11 +++
 2 files changed, 92 insertions(+), 5 deletions(-)
 rename pkg/init/cmd/service/{start.go => cmd.go} (66%)

diff --git a/pkg/init/cmd/service/start.go b/pkg/init/cmd/service/cmd.go
similarity index 66%
rename from pkg/init/cmd/service/start.go
rename to pkg/init/cmd/service/cmd.go
index 0e0341846..c5b9b6364 100644
--- a/pkg/init/cmd/service/start.go
+++ b/pkg/init/cmd/service/cmd.go
@@ -16,11 +16,11 @@ import (
 	log "github.com/sirupsen/logrus"
 )
 
-func startCmd(ctx context.Context, args []string) {
+func parseCmd(ctx context.Context, command string, args []string) (*log.Entry, string, string, string, string) {
 	invoked := filepath.Base(os.Args[0])
-	flags := flag.NewFlagSet("start", flag.ExitOnError)
+	flags := flag.NewFlagSet(command, flag.ExitOnError)
 	flags.Usage = func() {
-		fmt.Printf("USAGE: %s start [service]\n\n", invoked)
+		fmt.Printf("USAGE: %s %s [service]\n\n", invoked, command)
 		fmt.Printf("Options:\n")
 		flags.PrintDefaults()
 	}
@@ -43,12 +43,30 @@ func startCmd(ctx context.Context, args []string) {
 
 	service := args[0]
 
-	log.Infof("Starting service: %q", service)
 	log := log.WithFields(log.Fields{
 		"service": service,
 	})
 
-	id, pid, msg, err := start(ctx, service, *sock, *path, *dumpSpec)
+	return log, service, *sock, *path, *dumpSpec
+}
+
+func stopCmd(ctx context.Context, args []string) {
+	log, service, sock, path, _ := parseCmd(ctx, "stop", args)
+
+	log.Infof("Stopping service: %q", service)
+	id, pid, msg, err := stop(ctx, service, sock, path)
+	if err != nil {
+		log.WithError(err).Fatal(msg)
+	}
+
+	log.Debugf("Stopped %s pid %d", id, pid)
+}
+
+func startCmd(ctx context.Context, args []string) {
+	log, service, sock, path, dumpSpec := parseCmd(ctx, "start", args)
+
+	log.Infof("Starting service: %q", service)
+	id, pid, msg, err := start(ctx, service, sock, path, dumpSpec)
 	if err != nil {
 		log.WithError(err).Fatal(msg)
 	}
@@ -56,6 +74,14 @@ func startCmd(ctx context.Context, args []string) {
 	log.Debugf("Started %s pid %d", id, pid)
 }
 
+func restartCmd(ctx context.Context, args []string) {
+	// validate arguments with the command as "restart"
+	parseCmd(ctx, "restart", args)
+
+	stopCmd(ctx, args)
+	startCmd(ctx, args)
+}
+
 type logio struct {
 	config cio.Config
 }
@@ -74,6 +100,56 @@ func (c *logio) Close() error {
 	return nil
 }
 
+func stop(ctx context.Context, service, sock, basePath string) (string, uint32, string, error) {
+	path := filepath.Join(basePath, service)
+
+	runtimeConfig := getRuntimeConfig(path)
+
+	client, err := containerd.New(sock)
+	if err != nil {
+		return "", 0, "creating containerd client", err
+	}
+
+	if runtimeConfig.Namespace != "" {
+		ctx = namespaces.WithNamespace(ctx, runtimeConfig.Namespace)
+	}
+
+	ctr, err := client.LoadContainer(ctx, service)
+	if err != nil {
+		return "", 0, "loading container", err
+	}
+
+	task, err := ctr.Task(ctx, nil)
+	if err != nil {
+		return "", 0, "fetching task", err
+	}
+
+	id := ctr.ID()
+	pid := task.Pid()
+
+	err = task.Kill(ctx, 9)
+	if err != nil {
+		return "", 0, "killing task", err
+	}
+
+	_, err = task.Wait(ctx)
+	if err != nil {
+		return "", 0, "waiting for task to exit", err
+	}
+
+	_, err = task.Delete(ctx)
+	if err != nil {
+		return "", 0, "deleting task", err
+	}
+
+	err = ctr.Delete(ctx)
+	if err != nil {
+		return "", 0, "deleting container", err
+	}
+
+	return id, pid, "", nil
+}
+
 func start(ctx context.Context, service, sock, basePath, dumpSpec string) (string, uint32, string, error) {
 	path := filepath.Join(basePath, service)
 
diff --git a/pkg/init/cmd/service/main.go b/pkg/init/cmd/service/main.go
index d4816980c..1c03e3e13 100644
--- a/pkg/init/cmd/service/main.go
+++ b/pkg/init/cmd/service/main.go
@@ -43,7 +43,9 @@ func main() {
 		fmt.Printf("USAGE: %s [options] COMMAND\n\n", filepath.Base(os.Args[0]))
 		fmt.Printf("Commands:\n")
 		fmt.Printf("  system-init Prepare the system at start of day\n")
+		fmt.Printf("  stop        Stop a service\n")
 		fmt.Printf("  start       Start a service\n")
+		fmt.Printf("  restart     Restart a service\n")
 		fmt.Printf("  help        Print this message\n")
 		fmt.Printf("\n")
 		fmt.Printf("Run '%s COMMAND --help' for more information on the command\n", filepath.Base(os.Args[0]))
@@ -92,9 +94,18 @@ func main() {
 		}
 	}
 
+	if len(args) < 1 {
+		flag.Usage()
+		os.Exit(1)
+	}
+
 	switch args[0] {
+	case "stop":
+		stopCmd(ctx, args[1:])
 	case "start":
 		startCmd(ctx, args[1:])
+	case "restart":
+		restartCmd(ctx, args[1:])
 	case "system-init":
 		systemInitCmd(ctx, args[1:])
 	default: