blob: 159f0d5a7520b887ee4af3d7ddac81ba1ab66a3b [file] [log] [blame]
// +build linux
package main
import (
"errors"
"fmt"
"os"
"path/filepath"
"syscall"
"github.com/Sirupsen/logrus"
"github.com/codegangsta/cli"
"github.com/opencontainers/runc/libcontainer"
"github.com/opencontainers/runc/libcontainer/configs"
"github.com/opencontainers/specs"
)
const wildcard = -1
var errEmptyID = errors.New("container id cannot be empty")
var allowedDevices = []*configs.Device{
// allow mknod for any device
{
Type: 'c',
Major: wildcard,
Minor: wildcard,
Permissions: "m",
Allow: true,
},
{
Type: 'b',
Major: wildcard,
Minor: wildcard,
Permissions: "m",
Allow: true,
},
{
Type: 'c',
Path: "/dev/null",
Major: 1,
Minor: 3,
Permissions: "rwm",
Allow: true,
},
{
Type: 'c',
Path: "/dev/random",
Major: 1,
Minor: 8,
Permissions: "rwm",
Allow: true,
},
{
Type: 'c',
Path: "/dev/full",
Major: 1,
Minor: 7,
Permissions: "rwm",
Allow: true,
},
{
Type: 'c',
Path: "/dev/tty",
Major: 5,
Minor: 0,
Permissions: "rwm",
Allow: true,
},
{
Type: 'c',
Path: "/dev/zero",
Major: 1,
Minor: 5,
Permissions: "rwm",
Allow: true,
},
{
Type: 'c',
Path: "/dev/urandom",
Major: 1,
Minor: 9,
Permissions: "rwm",
Allow: true,
},
{
Path: "/dev/console",
Type: 'c',
Major: 5,
Minor: 1,
Permissions: "rwm",
Allow: true,
},
{
Path: "/dev/tty0",
Type: 'c',
Major: 4,
Minor: 0,
Permissions: "rwm",
Allow: true,
},
{
Path: "/dev/tty1",
Type: 'c',
Major: 4,
Minor: 1,
Permissions: "rwm",
Allow: true,
},
// /dev/pts/ - pts namespaces are "coming soon"
{
Path: "",
Type: 'c',
Major: 136,
Minor: wildcard,
Permissions: "rwm",
Allow: true,
},
{
Path: "",
Type: 'c',
Major: 5,
Minor: 2,
Permissions: "rwm",
Allow: true,
},
// tuntap
{
Path: "",
Type: 'c',
Major: 10,
Minor: 200,
Permissions: "rwm",
Allow: true,
},
}
var container libcontainer.Container
func containerPreload(context *cli.Context) error {
c, err := getContainer(context)
if err != nil {
return err
}
container = c
return nil
}
// loadFactory returns the configured factory instance for execing containers.
func loadFactory(context *cli.Context) (libcontainer.Factory, error) {
root := context.GlobalString("root")
abs, err := filepath.Abs(root)
if err != nil {
return nil, err
}
return libcontainer.New(abs, libcontainer.Cgroupfs, func(l *libcontainer.LinuxFactory) error {
l.CriuPath = context.GlobalString("criu")
return nil
})
}
// getContainer returns the specified container instance by loading it from state
// with the default factory.
func getContainer(context *cli.Context) (libcontainer.Container, error) {
id := context.Args().First()
if id == "" {
return nil, errEmptyID
}
factory, err := loadFactory(context)
if err != nil {
return nil, err
}
return factory.Load(id)
}
// fatal prints the error's details if it is a libcontainer specific error type
// then exits the program with an exit status of 1.
func fatal(err error) {
if lerr, ok := err.(libcontainer.Error); ok {
lerr.Detail(os.Stderr)
os.Exit(1)
}
fmt.Fprintln(os.Stderr, err)
os.Exit(1)
}
func getDefaultImagePath(context *cli.Context) string {
cwd, err := os.Getwd()
if err != nil {
panic(err)
}
return filepath.Join(cwd, "checkpoint")
}
// newProcess returns a new libcontainer Process with the arguments from the
// spec and stdio from the current process.
func newProcess(p specs.Process) *libcontainer.Process {
return &libcontainer.Process{
Args: p.Args,
Env: p.Env,
// TODO: fix libcontainer's API to better support uid/gid in a typesafe way.
User: fmt.Sprintf("%d:%d", p.User.UID, p.User.GID),
Cwd: p.Cwd,
}
}
func dupStdio(process *libcontainer.Process, rootuid int) error {
process.Stdin = os.Stdin
process.Stdout = os.Stdout
process.Stderr = os.Stderr
for _, fd := range []uintptr{
os.Stdin.Fd(),
os.Stdout.Fd(),
os.Stderr.Fd(),
} {
if err := syscall.Fchown(int(fd), rootuid, rootuid); err != nil {
return err
}
}
return nil
}
// If systemd is supporting sd_notify protocol, this function will add support
// for sd_notify protocol from within the container.
func setupSdNotify(spec *specs.LinuxSpec, notifySocket string) {
spec.Mounts = append(spec.Mounts, specs.Mount{Destination: notifySocket, Type: "bind", Source: notifySocket, Options: []string{"bind"}})
spec.Process.Env = append(spec.Process.Env, fmt.Sprintf("NOTIFY_SOCKET=%s", notifySocket))
}
func destroy(container libcontainer.Container) {
if err := container.Destroy(); err != nil {
logrus.Error(err)
}
}
func setupIO(process *libcontainer.Process, rootuid int, console string, createTTY, detach bool) (*tty, error) {
// detach and createTty will not work unless a console path is passed
// so error out here before changing any terminal settings
if createTTY && detach && console == "" {
return nil, fmt.Errorf("cannot allocate tty if runc will detach")
}
if createTTY {
return createTty(process, rootuid, console)
}
if detach {
if err := dupStdio(process, rootuid); err != nil {
return nil, err
}
return nil, nil
}
return createStdioPipes(process, rootuid)
}
func createPidFile(path string, process *libcontainer.Process) error {
pid, err := process.Pid()
if err != nil {
return err
}
f, err := os.Create(path)
if err != nil {
return err
}
defer f.Close()
_, err = fmt.Fprintf(f, "%d", pid)
return err
}
func createContainer(context *cli.Context, id string, spec *specs.LinuxSpec) (libcontainer.Container, error) {
config, err := createLibcontainerConfig(id, spec)
if err != nil {
return nil, err
}
if _, err := os.Stat(config.Rootfs); err != nil {
if os.IsNotExist(err) {
return nil, fmt.Errorf("rootfs (%q) does not exist", config.Rootfs)
}
return nil, err
}
factory, err := loadFactory(context)
if err != nil {
return nil, err
}
return factory.Create(id, config)
}
// runProcess will create a new process in the specified container
// by executing the process specified in the 'config'.
func runProcess(container libcontainer.Container, config *specs.Process, listenFDs []*os.File, console string, pidFile string, detach bool) (int, error) {
process := newProcess(*config)
// Add extra file descriptors if needed
if len(listenFDs) > 0 {
process.Env = append(process.Env, fmt.Sprintf("LISTEN_FDS=%d", len(listenFDs)), "LISTEN_PID=1")
process.ExtraFiles = append(process.ExtraFiles, listenFDs...)
}
rootuid, err := container.Config().HostUID()
if err != nil {
return -1, err
}
tty, err := setupIO(process, rootuid, console, config.Terminal, detach)
if err != nil {
return -1, err
}
if err := container.Start(process); err != nil {
return -1, err
}
if pidFile != "" {
if err := createPidFile(pidFile, process); err != nil {
process.Signal(syscall.SIGKILL)
process.Wait()
return -1, err
}
}
if detach {
return 0, nil
}
handler := newSignalHandler(tty)
defer handler.Close()
return handler.forward(process)
}