runc/restore.go

132 lines
3.6 KiB
Go

package main
import (
"os"
"os/signal"
"syscall"
"github.com/Sirupsen/logrus"
"github.com/codegangsta/cli"
"github.com/opencontainers/runc/libcontainer"
"github.com/opencontainers/runc/libcontainer/configs"
"github.com/opencontainers/runc/libcontainer/utils"
)
var restoreCommand = cli.Command{
Name: "restore",
Usage: "restore a container from a previous checkpoint",
Flags: []cli.Flag{
cli.StringFlag{Name: "image-path", Value: "", Usage: "path to criu image files for restoring"},
cli.StringFlag{Name: "work-path", Value: "", Usage: "path for saving work files and logs"},
cli.BoolFlag{Name: "tcp-established", Usage: "allow open tcp connections"},
cli.BoolFlag{Name: "ext-unix-sk", Usage: "allow external unix sockets"},
cli.BoolFlag{Name: "shell-job", Usage: "allow shell jobs"},
cli.BoolFlag{Name: "file-locks", Usage: "handle file locks, for safety"},
},
Action: func(context *cli.Context) {
imagePath := context.String("image-path")
if imagePath == "" {
imagePath = getDefaultImagePath(context)
}
spec, err := loadSpec(context.Args().First())
if err != nil {
fatal(err)
}
config, err := createLibcontainerConfig(spec)
if err != nil {
fatal(err)
}
status, err := restoreContainer(context, spec, config, imagePath)
if err != nil {
fatal(err)
}
os.Exit(status)
},
}
func restoreContainer(context *cli.Context, spec *Spec, config *configs.Config, imagePath string) (code int, err error) {
rootuid := 0
factory, err := loadFactory(context)
if err != nil {
return -1, err
}
container, err := factory.Load(context.GlobalString("id"))
if err != nil {
container, err = factory.Create(context.GlobalString("id"), config)
if err != nil {
return -1, err
}
}
options := criuOptions(context)
// ensure that the container is always removed if we were the process
// that created it.
defer func() {
if err != nil {
return
}
status, err := container.Status()
if err != nil {
logrus.Error(err)
}
if status != libcontainer.Checkpointed {
if err := container.Destroy(); err != nil {
logrus.Error(err)
}
if err := os.RemoveAll(options.ImagesDirectory); err != nil {
logrus.Error(err)
}
}
}()
process := &libcontainer.Process{
Stdin: os.Stdin,
Stdout: os.Stdout,
Stderr: os.Stderr,
}
tty, err := newTty(spec.Process.Terminal, process, rootuid)
if err != nil {
return -1, err
}
defer tty.Close()
go handleSignals(process, tty)
if err := container.Restore(process, options); err != nil {
return -1, err
}
status, err := process.Wait()
if err != nil {
return -1, err
}
return utils.ExitStatus(status.Sys().(syscall.WaitStatus)), nil
}
func criuOptions(context *cli.Context) *libcontainer.CriuOpts {
imagePath := getCheckpointImagePath(context)
if err := os.MkdirAll(imagePath, 0655); err != nil {
fatal(err)
}
return &libcontainer.CriuOpts{
ImagesDirectory: imagePath,
WorkDirectory: context.String("work-path"),
LeaveRunning: context.Bool("leave-running"),
TcpEstablished: true, // context.Bool("tcp-established"),
ExternalUnixConnections: context.Bool("ext-unix-sk"),
ShellJob: context.Bool("shell-job"),
FileLocks: context.Bool("file-locks"),
}
}
// we have to use this type of signal handler because there is a memory leak if we
// wait and reap with SICHLD.
func handleSignals(process *libcontainer.Process, tty *tty) {
sigc := make(chan os.Signal, 10)
signal.Notify(sigc)
tty.resize()
for sig := range sigc {
switch sig {
case syscall.SIGWINCH:
tty.resize()
default:
process.Signal(sig)
}
}
}