Initial windows runtime work

Signed-off-by: Kenfe-Mickael Laventure <mickael.laventure@gmail.com>
2017-03-17 16:09:06 -07:00
parent e5c8c5634a
commit c5843b7615
120 changed files with 11158 additions and 596 deletions
--- a/cmd/containerd-shim/main_unix.go
+++ b/cmd/containerd-shim/main_unix.go
@@ -0,0 +1,137 @@
+// +build !windows
+
+package main
+
+import (
+	"fmt"
+	"net"
+	"os"
+	"os/signal"
+	"strings"
+	"syscall"
+
+	"google.golang.org/grpc"
+
+	"github.com/Sirupsen/logrus"
+	"github.com/containerd/containerd"
+	shimapi "github.com/containerd/containerd/api/services/shim"
+	"github.com/containerd/containerd/linux/shim"
+	"github.com/containerd/containerd/reaper"
+	"github.com/containerd/containerd/sys"
+	runc "github.com/crosbymichael/go-runc"
+	"github.com/urfave/cli"
+)
+
+const usage = `
+                    __        _                     __           __    _         
+  _________  ____  / /_____ _(_)___  ___  _________/ /     _____/ /_  (_)___ ___ 
+ / ___/ __ \/ __ \/ __/ __ ` + "`" + `/ / __ \/ _ \/ ___/ __  /_____/ ___/ __ \/ / __ ` + "`" + `__ \
+/ /__/ /_/ / / / / /_/ /_/ / / / / /  __/ /  / /_/ /_____(__  ) / / / / / / / / /
+\___/\____/_/ /_/\__/\__,_/_/_/ /_/\___/_/   \__,_/     /____/_/ /_/_/_/ /_/ /_/ 
+                                                                                 
+shim for container lifecycle and reconnection
+`
+
+func main() {
+	app := cli.NewApp()
+	app.Name = "containerd-shim"
+	app.Version = containerd.Version
+	app.Usage = usage
+	app.Flags = []cli.Flag{
+		cli.BoolFlag{
+			Name:  "debug",
+			Usage: "enable debug output in logs",
+		},
+	}
+	app.Before = func(context *cli.Context) error {
+		if context.GlobalBool("debug") {
+			logrus.SetLevel(logrus.DebugLevel)
+		}
+		return nil
+	}
+	app.Action = func(context *cli.Context) error {
+		// start handling signals as soon as possible so that things are properly reaped
+		// or if runtime exits before we hit the handler
+		signals, err := setupSignals()
+		if err != nil {
+			return err
+		}
+		if err := setupRoot(); err != nil {
+			return err
+		}
+		path, err := os.Getwd()
+		if err != nil {
+			return err
+		}
+		var (
+			server = grpc.NewServer()
+			sv     = shim.New(path)
+		)
+		logrus.Debug("registering grpc server")
+		shimapi.RegisterShimServer(server, sv)
+		if err := serve(server, "shim.sock"); err != nil {
+			return err
+		}
+		return handleSignals(signals, server)
+	}
+	if err := app.Run(os.Args); err != nil {
+		fmt.Fprintf(os.Stderr, "containerd-shim: %s\n", err)
+		os.Exit(1)
+	}
+}
+
+// setupSignals creates a new signal handler for all signals and sets the shim as a
+// sub-reaper so that the container processes are reparented
+func setupSignals() (chan os.Signal, error) {
+	signals := make(chan os.Signal, 2048)
+	signal.Notify(signals)
+	// make sure runc is setup to use the monitor
+	// for waiting on processes
+	runc.Monitor = reaper.Default
+	// set the shim as the subreaper for all orphaned processes created by the container
+	if err := sys.SetSubreaper(1); err != nil {
+		return nil, err
+	}
+	return signals, nil
+}
+
+// serve serves the grpc API over a unix socket at the provided path
+// this function does not block
+func serve(server *grpc.Server, path string) error {
+	l, err := net.FileListener(os.NewFile(3, "socket"))
+	if err != nil {
+		return err
+	}
+	logrus.WithField("socket", path).Debug("serving api on unix socket")
+	go func() {
+		defer l.Close()
+		if err := server.Serve(l); err != nil &&
+			!strings.Contains(err.Error(), "use of closed network connection") {
+			logrus.WithError(err).Fatal("containerd-shim: GRPC server failure")
+		}
+	}()
+	return nil
+}
+
+func handleSignals(signals chan os.Signal, server *grpc.Server) error {
+	for s := range signals {
+		logrus.WithField("signal", s).Debug("received signal")
+		switch s {
+		case syscall.SIGCHLD:
+			if err := reaper.Reap(); err != nil {
+				logrus.WithError(err).Error("reap exit status")
+			}
+		case syscall.SIGTERM, syscall.SIGINT:
+			// TODO: should we forward signals to the processes if they are still running?
+			// i.e. machine reboot
+			server.Stop()
+			return nil
+		}
+	}
+	return nil
+}
+
+// setupRoot sets up the root as the shim is started in its own mount namespace
+func setupRoot() error {
+	return syscall.Mount("", "/", "", syscall.MS_SLAVE|syscall.MS_REC, "")
+}