traefik/vendor/github.com/opencontainers/runc/restore.go

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// +build linux
package main
import (
"fmt"
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"os"
"syscall"
"github.com/Sirupsen/logrus"
"github.com/opencontainers/runc/libcontainer"
"github.com/opencontainers/runc/libcontainer/configs"
"github.com/opencontainers/runc/libcontainer/specconv"
"github.com/opencontainers/runtime-spec/specs-go"
"github.com/urfave/cli"
)
var restoreCommand = cli.Command{
Name: "restore",
Usage: "restore a container from a previous checkpoint",
ArgsUsage: `<container-id>
Where "<container-id>" is the name for the instance of the container to be
restored.`,
Description: `Restores the saved state of the container instance that was previously saved
using the runc checkpoint command.`,
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",
},
cli.StringFlag{
Name: "manage-cgroups-mode",
Value: "",
Usage: "cgroups mode: 'soft' (default), 'full' and 'strict'",
},
cli.StringFlag{
Name: "bundle, b",
Value: "",
Usage: "path to the root of the bundle directory",
},
cli.BoolFlag{
Name: "detach,d",
Usage: "detach from the container's process",
},
cli.StringFlag{
Name: "pid-file",
Value: "",
Usage: "specify the file to write the process id to",
},
cli.BoolFlag{
Name: "no-subreaper",
Usage: "disable the use of the subreaper used to reap reparented processes",
},
cli.BoolFlag{
Name: "no-pivot",
Usage: "do not use pivot root to jail process inside rootfs. This should be used whenever the rootfs is on top of a ramdisk",
},
cli.StringSliceFlag{
Name: "empty-ns",
Usage: "create a namespace, but don't restore its properties",
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},
},
Action: func(context *cli.Context) error {
if err := checkArgs(context, 1, exactArgs); err != nil {
return err
}
// XXX: Currently this is untested with rootless containers.
if isRootless() {
return fmt.Errorf("runc restore requires root")
}
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imagePath := context.String("image-path")
id := context.Args().First()
if id == "" {
return errEmptyID
}
if imagePath == "" {
imagePath = getDefaultImagePath(context)
}
bundle := context.String("bundle")
if bundle != "" {
if err := os.Chdir(bundle); err != nil {
return err
}
}
spec, err := loadSpec(specConfig)
if err != nil {
return err
}
config, err := specconv.CreateLibcontainerConfig(&specconv.CreateOpts{
CgroupName: id,
UseSystemdCgroup: context.GlobalBool("systemd-cgroup"),
NoPivotRoot: context.Bool("no-pivot"),
Spec: spec,
})
if err != nil {
return err
}
status, err := restoreContainer(context, spec, config, imagePath)
if err == nil {
os.Exit(status)
}
return err
},
}
func restoreContainer(context *cli.Context, spec *specs.Spec, config *configs.Config, imagePath string) (int, error) {
var (
rootuid = 0
rootgid = 0
id = context.Args().First()
)
factory, err := loadFactory(context)
if err != nil {
return -1, err
}
container, err := factory.Load(id)
if err != nil {
container, err = factory.Create(id, config)
if err != nil {
return -1, err
}
}
options := criuOptions(context)
status, err := container.Status()
if err != nil {
logrus.Error(err)
}
if status == libcontainer.Running {
fatalf("Container with id %s already running", id)
}
setManageCgroupsMode(context, options)
if err = setEmptyNsMask(context, options); err != nil {
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return -1, err
}
// ensure that the container is always removed if we were the process
// that created it.
detach := context.Bool("detach")
if !detach {
defer destroy(container)
}
process := &libcontainer.Process{}
tty, err := setupIO(process, rootuid, rootgid, false, detach, "")
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if err != nil {
return -1, err
}
notifySocket := newNotifySocket(context, os.Getenv("NOTIFY_SOCKET"), id)
if notifySocket != nil {
notifySocket.setupSpec(context, spec)
notifySocket.setupSocket()
}
handler := newSignalHandler(!context.Bool("no-subreaper"), notifySocket)
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if err := container.Restore(process, options); err != nil {
return -1, err
}
// We don't need to do a tty.recvtty because config.Terminal is always false.
defer tty.Close()
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if err := tty.ClosePostStart(); err != nil {
return -1, err
}
if pidFile := context.String("pid-file"); pidFile != "" {
if err := createPidFile(pidFile, process); err != nil {
_ = process.Signal(syscall.SIGKILL)
_, _ = process.Wait()
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return -1, err
}
}
return handler.forward(process, tty, detach)
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}
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"),
ParentImage: context.String("parent-path"),
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LeaveRunning: context.Bool("leave-running"),
TcpEstablished: context.Bool("tcp-established"),
ExternalUnixConnections: context.Bool("ext-unix-sk"),
ShellJob: context.Bool("shell-job"),
FileLocks: context.Bool("file-locks"),
PreDump: context.Bool("pre-dump"),
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}
}