blob: 9210ec6a3b94dcf6c441482e6b7722c9658990ac [file] [log] [blame]
// +build linux
package libcontainer
import (
"encoding/json"
"fmt"
"io/ioutil"
"os"
"os/exec"
"path/filepath"
"strings"
"sync"
"syscall"
"github.com/Sirupsen/logrus"
"github.com/golang/protobuf/proto"
"github.com/opencontainers/runc/libcontainer/cgroups"
"github.com/opencontainers/runc/libcontainer/configs"
"github.com/opencontainers/runc/libcontainer/criurpc"
)
const stdioFdCount = 3
type linuxContainer struct {
id string
root string
config *configs.Config
cgroupManager cgroups.Manager
initPath string
initArgs []string
initProcess parentProcess
criuPath string
m sync.Mutex
}
// ID returns the container's unique ID
func (c *linuxContainer) ID() string {
return c.id
}
// Config returns the container's configuration
func (c *linuxContainer) Config() configs.Config {
return *c.config
}
func (c *linuxContainer) Status() (Status, error) {
c.m.Lock()
defer c.m.Unlock()
return c.currentStatus()
}
func (c *linuxContainer) State() (*State, error) {
c.m.Lock()
defer c.m.Unlock()
return c.currentState()
}
func (c *linuxContainer) Processes() ([]int, error) {
pids, err := c.cgroupManager.GetPids()
if err != nil {
return nil, newSystemError(err)
}
return pids, nil
}
func (c *linuxContainer) Stats() (*Stats, error) {
var (
err error
stats = &Stats{}
)
if stats.CgroupStats, err = c.cgroupManager.GetStats(); err != nil {
return stats, newSystemError(err)
}
for _, iface := range c.config.Networks {
switch iface.Type {
case "veth":
istats, err := getNetworkInterfaceStats(iface.HostInterfaceName)
if err != nil {
return stats, newSystemError(err)
}
stats.Interfaces = append(stats.Interfaces, istats)
}
}
return stats, nil
}
func (c *linuxContainer) Set(config configs.Config) error {
c.m.Lock()
defer c.m.Unlock()
c.config = &config
return c.cgroupManager.Set(c.config)
}
func (c *linuxContainer) Start(process *Process) error {
c.m.Lock()
defer c.m.Unlock()
status, err := c.currentStatus()
if err != nil {
return err
}
doInit := status == Destroyed
parent, err := c.newParentProcess(process, doInit)
if err != nil {
return newSystemError(err)
}
if err := parent.start(); err != nil {
// terminate the process to ensure that it properly is reaped.
if err := parent.terminate(); err != nil {
logrus.Warn(err)
}
return newSystemError(err)
}
process.ops = parent
if doInit {
c.updateState(parent)
}
return nil
}
func (c *linuxContainer) Signal(s os.Signal) error {
if err := c.initProcess.signal(s); err != nil {
return newSystemError(err)
}
return nil
}
func (c *linuxContainer) newParentProcess(p *Process, doInit bool) (parentProcess, error) {
parentPipe, childPipe, err := newPipe()
if err != nil {
return nil, newSystemError(err)
}
cmd, err := c.commandTemplate(p, childPipe)
if err != nil {
return nil, newSystemError(err)
}
if !doInit {
return c.newSetnsProcess(p, cmd, parentPipe, childPipe), nil
}
return c.newInitProcess(p, cmd, parentPipe, childPipe)
}
func (c *linuxContainer) commandTemplate(p *Process, childPipe *os.File) (*exec.Cmd, error) {
cmd := &exec.Cmd{
Path: c.initPath,
Args: c.initArgs,
}
cmd.Stdin = p.Stdin
cmd.Stdout = p.Stdout
cmd.Stderr = p.Stderr
cmd.Dir = c.config.Rootfs
if cmd.SysProcAttr == nil {
cmd.SysProcAttr = &syscall.SysProcAttr{}
}
cmd.ExtraFiles = append(p.ExtraFiles, childPipe)
cmd.Env = append(cmd.Env, fmt.Sprintf("_LIBCONTAINER_INITPIPE=%d", stdioFdCount+len(cmd.ExtraFiles)-1))
// NOTE: when running a container with no PID namespace and the parent process spawning the container is
// PID1 the pdeathsig is being delivered to the container's init process by the kernel for some reason
// even with the parent still running.
if c.config.ParentDeathSignal > 0 {
cmd.SysProcAttr.Pdeathsig = syscall.Signal(c.config.ParentDeathSignal)
}
return cmd, nil
}
func (c *linuxContainer) newInitProcess(p *Process, cmd *exec.Cmd, parentPipe, childPipe *os.File) (*initProcess, error) {
t := "_LIBCONTAINER_INITTYPE=standard"
cloneFlags := c.config.Namespaces.CloneFlags()
if cloneFlags&syscall.CLONE_NEWUSER != 0 {
if err := c.addUidGidMappings(cmd.SysProcAttr); err != nil {
// user mappings are not supported
return nil, err
}
enableSetgroups(cmd.SysProcAttr)
// Default to root user when user namespaces are enabled.
if cmd.SysProcAttr.Credential == nil {
cmd.SysProcAttr.Credential = &syscall.Credential{}
}
}
cmd.Env = append(cmd.Env, t)
cmd.SysProcAttr.Cloneflags = cloneFlags
return &initProcess{
cmd: cmd,
childPipe: childPipe,
parentPipe: parentPipe,
manager: c.cgroupManager,
config: c.newInitConfig(p),
}, nil
}
func (c *linuxContainer) newSetnsProcess(p *Process, cmd *exec.Cmd, parentPipe, childPipe *os.File) *setnsProcess {
cmd.Env = append(cmd.Env,
fmt.Sprintf("_LIBCONTAINER_INITPID=%d", c.initProcess.pid()),
"_LIBCONTAINER_INITTYPE=setns",
)
if p.consolePath != "" {
cmd.Env = append(cmd.Env, "_LIBCONTAINER_CONSOLE_PATH="+p.consolePath)
}
// TODO: set on container for process management
return &setnsProcess{
cmd: cmd,
cgroupPaths: c.cgroupManager.GetPaths(),
childPipe: childPipe,
parentPipe: parentPipe,
config: c.newInitConfig(p),
}
}
func (c *linuxContainer) newInitConfig(process *Process) *initConfig {
return &initConfig{
Config: c.config,
Args: process.Args,
Env: process.Env,
User: process.User,
Cwd: process.Cwd,
Console: process.consolePath,
Capabilities: process.Capabilities,
PassedFilesCount: len(process.ExtraFiles),
}
}
func newPipe() (parent *os.File, child *os.File, err error) {
fds, err := syscall.Socketpair(syscall.AF_LOCAL, syscall.SOCK_STREAM|syscall.SOCK_CLOEXEC, 0)
if err != nil {
return nil, nil, err
}
return os.NewFile(uintptr(fds[1]), "parent"), os.NewFile(uintptr(fds[0]), "child"), nil
}
func (c *linuxContainer) Destroy() error {
c.m.Lock()
defer c.m.Unlock()
status, err := c.currentStatus()
if err != nil {
return err
}
if status != Destroyed {
return newGenericError(fmt.Errorf("container is not destroyed"), ContainerNotStopped)
}
if !c.config.Namespaces.Contains(configs.NEWPID) {
if err := killCgroupProcesses(c.cgroupManager); err != nil {
logrus.Warn(err)
}
}
err = c.cgroupManager.Destroy()
if rerr := os.RemoveAll(c.root); err == nil {
err = rerr
}
c.initProcess = nil
return err
}
func (c *linuxContainer) Pause() error {
c.m.Lock()
defer c.m.Unlock()
return c.cgroupManager.Freeze(configs.Frozen)
}
func (c *linuxContainer) Resume() error {
c.m.Lock()
defer c.m.Unlock()
return c.cgroupManager.Freeze(configs.Thawed)
}
func (c *linuxContainer) NotifyOOM() (<-chan struct{}, error) {
return notifyOnOOM(c.cgroupManager.GetPaths())
}
// XXX debug support, remove when debugging done.
func addArgsFromEnv(evar string, args *[]string) {
if e := os.Getenv(evar); e != "" {
for _, f := range strings.Fields(e) {
*args = append(*args, f)
}
}
fmt.Printf(">>> criu %v\n", *args)
}
func (c *linuxContainer) checkCriuVersion() error {
var x, y, z int
out, err := exec.Command(c.criuPath, "-V").Output()
if err != nil {
return fmt.Errorf("Unable to execute CRIU command: %s", c.criuPath)
}
n, err := fmt.Sscanf(string(out), "Version: %d.%d.%d\n", &x, &y, &z) // 1.5.2
if err != nil {
n, err = fmt.Sscanf(string(out), "Version: %d.%d\n", &x, &y) // 1.6
}
if n < 2 || err != nil {
return fmt.Errorf("Unable to parse the CRIU version: %s %d %s", out, n, err)
}
if x*10000+y*100+z < 10502 {
return fmt.Errorf("CRIU version must be 1.5.2 or higher")
}
return nil
}
const descriptorsFilename = "descriptors.json"
func (c *linuxContainer) addCriuDumpMount(req *criurpc.CriuReq, m *configs.Mount) {
mountDest := m.Destination
if strings.HasPrefix(mountDest, c.config.Rootfs) {
mountDest = mountDest[len(c.config.Rootfs):]
}
extMnt := &criurpc.ExtMountMap{
Key: proto.String(mountDest),
Val: proto.String(mountDest),
}
req.Opts.ExtMnt = append(req.Opts.ExtMnt, extMnt)
}
func (c *linuxContainer) Checkpoint(criuOpts *CriuOpts) error {
c.m.Lock()
defer c.m.Unlock()
if err := c.checkCriuVersion(); err != nil {
return err
}
if criuOpts.ImagesDirectory == "" {
criuOpts.ImagesDirectory = filepath.Join(c.root, "criu.image")
}
// Since a container can be C/R'ed multiple times,
// the checkpoint directory may already exist.
if err := os.Mkdir(criuOpts.ImagesDirectory, 0755); err != nil && !os.IsExist(err) {
return err
}
if criuOpts.WorkDirectory == "" {
criuOpts.WorkDirectory = filepath.Join(c.root, "criu.work")
}
if err := os.Mkdir(criuOpts.WorkDirectory, 0755); err != nil && !os.IsExist(err) {
return err
}
workDir, err := os.Open(criuOpts.WorkDirectory)
if err != nil {
return err
}
defer workDir.Close()
imageDir, err := os.Open(criuOpts.ImagesDirectory)
if err != nil {
return err
}
defer imageDir.Close()
rpcOpts := criurpc.CriuOpts{
ImagesDirFd: proto.Int32(int32(imageDir.Fd())),
WorkDirFd: proto.Int32(int32(workDir.Fd())),
LogLevel: proto.Int32(4),
LogFile: proto.String("dump.log"),
Root: proto.String(c.config.Rootfs),
ManageCgroups: proto.Bool(true),
NotifyScripts: proto.Bool(true),
Pid: proto.Int32(int32(c.initProcess.pid())),
ShellJob: proto.Bool(criuOpts.ShellJob),
LeaveRunning: proto.Bool(criuOpts.LeaveRunning),
TcpEstablished: proto.Bool(criuOpts.TcpEstablished),
ExtUnixSk: proto.Bool(criuOpts.ExternalUnixConnections),
FileLocks: proto.Bool(criuOpts.FileLocks),
}
// append optional criu opts, e.g., page-server and port
if criuOpts.PageServer.Address != "" && criuOpts.PageServer.Port != 0 {
rpcOpts.Ps = &criurpc.CriuPageServerInfo{
Address: proto.String(criuOpts.PageServer.Address),
Port: proto.Int32(criuOpts.PageServer.Port),
}
}
t := criurpc.CriuReqType_DUMP
req := &criurpc.CriuReq{
Type: &t,
Opts: &rpcOpts,
}
for _, m := range c.config.Mounts {
switch m.Device {
case "bind":
c.addCriuDumpMount(req, m)
break
case "cgroup":
binds, err := getCgroupMounts(m)
if err != nil {
return err
}
for _, b := range binds {
c.addCriuDumpMount(req, b)
}
break
}
}
// Write the FD info to a file in the image directory
fdsJSON, err := json.Marshal(c.initProcess.externalDescriptors())
if err != nil {
return err
}
err = ioutil.WriteFile(filepath.Join(criuOpts.ImagesDirectory, descriptorsFilename), fdsJSON, 0655)
if err != nil {
return err
}
err = c.criuSwrk(nil, req, criuOpts)
if err != nil {
return err
}
return nil
}
func (c *linuxContainer) addCriuRestoreMount(req *criurpc.CriuReq, m *configs.Mount) {
mountDest := m.Destination
if strings.HasPrefix(mountDest, c.config.Rootfs) {
mountDest = mountDest[len(c.config.Rootfs):]
}
extMnt := &criurpc.ExtMountMap{
Key: proto.String(mountDest),
Val: proto.String(m.Source),
}
req.Opts.ExtMnt = append(req.Opts.ExtMnt, extMnt)
}
func (c *linuxContainer) Restore(process *Process, criuOpts *CriuOpts) error {
c.m.Lock()
defer c.m.Unlock()
if err := c.checkCriuVersion(); err != nil {
return err
}
if criuOpts.WorkDirectory == "" {
criuOpts.WorkDirectory = filepath.Join(c.root, "criu.work")
}
// Since a container can be C/R'ed multiple times,
// the work directory may already exist.
if err := os.Mkdir(criuOpts.WorkDirectory, 0655); err != nil && !os.IsExist(err) {
return err
}
workDir, err := os.Open(criuOpts.WorkDirectory)
if err != nil {
return err
}
defer workDir.Close()
if criuOpts.ImagesDirectory == "" {
criuOpts.ImagesDirectory = filepath.Join(c.root, "criu.image")
}
imageDir, err := os.Open(criuOpts.ImagesDirectory)
if err != nil {
return err
}
defer imageDir.Close()
// CRIU has a few requirements for a root directory:
// * it must be a mount point
// * its parent must not be overmounted
// c.config.Rootfs is bind-mounted to a temporary directory
// to satisfy these requirements.
root := filepath.Join(c.root, "criu-root")
if err := os.Mkdir(root, 0755); err != nil {
return err
}
defer os.Remove(root)
root, err = filepath.EvalSymlinks(root)
if err != nil {
return err
}
err = syscall.Mount(c.config.Rootfs, root, "", syscall.MS_BIND|syscall.MS_REC, "")
if err != nil {
return err
}
defer syscall.Unmount(root, syscall.MNT_DETACH)
t := criurpc.CriuReqType_RESTORE
req := &criurpc.CriuReq{
Type: &t,
Opts: &criurpc.CriuOpts{
ImagesDirFd: proto.Int32(int32(imageDir.Fd())),
WorkDirFd: proto.Int32(int32(workDir.Fd())),
EvasiveDevices: proto.Bool(true),
LogLevel: proto.Int32(4),
LogFile: proto.String("restore.log"),
RstSibling: proto.Bool(true),
Root: proto.String(root),
ManageCgroups: proto.Bool(true),
NotifyScripts: proto.Bool(true),
ShellJob: proto.Bool(criuOpts.ShellJob),
ExtUnixSk: proto.Bool(criuOpts.ExternalUnixConnections),
TcpEstablished: proto.Bool(criuOpts.TcpEstablished),
FileLocks: proto.Bool(criuOpts.FileLocks),
},
}
for _, m := range c.config.Mounts {
switch m.Device {
case "bind":
c.addCriuRestoreMount(req, m)
break
case "cgroup":
binds, err := getCgroupMounts(m)
if err != nil {
return err
}
for _, b := range binds {
c.addCriuRestoreMount(req, b)
}
break
}
}
for _, iface := range c.config.Networks {
switch iface.Type {
case "veth":
veth := new(criurpc.CriuVethPair)
veth.IfOut = proto.String(iface.HostInterfaceName)
veth.IfIn = proto.String(iface.Name)
req.Opts.Veths = append(req.Opts.Veths, veth)
break
case "loopback":
break
}
}
for _, i := range criuOpts.VethPairs {
veth := new(criurpc.CriuVethPair)
veth.IfOut = proto.String(i.HostInterfaceName)
veth.IfIn = proto.String(i.ContainerInterfaceName)
req.Opts.Veths = append(req.Opts.Veths, veth)
}
var (
fds []string
fdJSON []byte
)
if fdJSON, err = ioutil.ReadFile(filepath.Join(criuOpts.ImagesDirectory, descriptorsFilename)); err != nil {
return err
}
if err = json.Unmarshal(fdJSON, &fds); err != nil {
return err
}
for i := range fds {
if s := fds[i]; strings.Contains(s, "pipe:") {
inheritFd := new(criurpc.InheritFd)
inheritFd.Key = proto.String(s)
inheritFd.Fd = proto.Int32(int32(i))
req.Opts.InheritFd = append(req.Opts.InheritFd, inheritFd)
}
}
err = c.criuSwrk(process, req, criuOpts)
if err != nil {
return err
}
return nil
}
func (c *linuxContainer) criuSwrk(process *Process, req *criurpc.CriuReq, opts *CriuOpts) error {
fds, err := syscall.Socketpair(syscall.AF_LOCAL, syscall.SOCK_SEQPACKET|syscall.SOCK_CLOEXEC, 0)
if err != nil {
return err
}
logPath := filepath.Join(opts.WorkDirectory, req.GetOpts().GetLogFile())
criuClient := os.NewFile(uintptr(fds[0]), "criu-transport-client")
criuServer := os.NewFile(uintptr(fds[1]), "criu-transport-server")
defer criuClient.Close()
defer criuServer.Close()
args := []string{"swrk", "3"}
cmd := exec.Command(c.criuPath, args...)
if process != nil {
cmd.Stdin = process.Stdin
cmd.Stdout = process.Stdout
cmd.Stderr = process.Stderr
}
cmd.ExtraFiles = append(cmd.ExtraFiles, criuServer)
if err := cmd.Start(); err != nil {
return err
}
criuServer.Close()
defer func() {
criuClient.Close()
_, err := cmd.Process.Wait()
if err != nil {
return
}
}()
var extFds []string
if process != nil {
extFds, err = getPipeFds(cmd.Process.Pid)
if err != nil {
return err
}
}
data, err := proto.Marshal(req)
if err != nil {
return err
}
_, err = criuClient.Write(data)
if err != nil {
return err
}
buf := make([]byte, 10*4096)
for true {
n, err := criuClient.Read(buf)
if err != nil {
return err
}
if n == 0 {
return fmt.Errorf("unexpected EOF")
}
if n == len(buf) {
return fmt.Errorf("buffer is too small")
}
resp := new(criurpc.CriuResp)
err = proto.Unmarshal(buf[:n], resp)
if err != nil {
return err
}
if !resp.GetSuccess() {
typeString := req.GetType().String()
return fmt.Errorf("criu failed: type %s errno %d\nlog file: %s", typeString, resp.GetCrErrno(), logPath)
}
t := resp.GetType()
switch {
case t == criurpc.CriuReqType_NOTIFY:
if err := c.criuNotifications(resp, process, opts, extFds); err != nil {
return err
}
t = criurpc.CriuReqType_NOTIFY
req = &criurpc.CriuReq{
Type: &t,
NotifySuccess: proto.Bool(true),
}
data, err = proto.Marshal(req)
if err != nil {
return err
}
n, err = criuClient.Write(data)
if err != nil {
return err
}
continue
case t == criurpc.CriuReqType_RESTORE:
case t == criurpc.CriuReqType_DUMP:
break
default:
return fmt.Errorf("unable to parse the response %s", resp.String())
}
break
}
// cmd.Wait() waits cmd.goroutines which are used for proxying file descriptors.
// Here we want to wait only the CRIU process.
st, err := cmd.Process.Wait()
if err != nil {
return err
}
if !st.Success() {
return fmt.Errorf("criu failed: %s\nlog file: %s", st.String(), logPath)
}
return nil
}
// block any external network activity
func lockNetwork(config *configs.Config) error {
for _, config := range config.Networks {
strategy, err := getStrategy(config.Type)
if err != nil {
return err
}
if err := strategy.detach(config); err != nil {
return err
}
}
return nil
}
func unlockNetwork(config *configs.Config) error {
for _, config := range config.Networks {
strategy, err := getStrategy(config.Type)
if err != nil {
return err
}
if err = strategy.attach(config); err != nil {
return err
}
}
return nil
}
func (c *linuxContainer) criuNotifications(resp *criurpc.CriuResp, process *Process, opts *CriuOpts, fds []string) error {
notify := resp.GetNotify()
if notify == nil {
return fmt.Errorf("invalid response: %s", resp.String())
}
switch {
case notify.GetScript() == "post-dump":
if !opts.LeaveRunning {
f, err := os.Create(filepath.Join(c.root, "checkpoint"))
if err != nil {
return err
}
f.Close()
}
break
case notify.GetScript() == "network-unlock":
if err := unlockNetwork(c.config); err != nil {
return err
}
break
case notify.GetScript() == "network-lock":
if err := lockNetwork(c.config); err != nil {
return err
}
break
case notify.GetScript() == "post-restore":
pid := notify.GetPid()
r, err := newRestoredProcess(int(pid), fds)
if err != nil {
return err
}
// TODO: crosbymichael restore previous process information by saving the init process information in
// the container's state file or separate process state files.
if err := c.updateState(r); err != nil {
return err
}
process.ops = r
break
}
return nil
}
func (c *linuxContainer) updateState(process parentProcess) error {
c.initProcess = process
state, err := c.currentState()
if err != nil {
return err
}
f, err := os.Create(filepath.Join(c.root, stateFilename))
if err != nil {
return err
}
defer f.Close()
os.Remove(filepath.Join(c.root, "checkpoint"))
return json.NewEncoder(f).Encode(state)
}
func (c *linuxContainer) currentStatus() (Status, error) {
if _, err := os.Stat(filepath.Join(c.root, "checkpoint")); err == nil {
return Checkpointed, nil
}
if c.initProcess == nil {
return Destroyed, nil
}
// return Running if the init process is alive
if err := syscall.Kill(c.initProcess.pid(), 0); err != nil {
if err == syscall.ESRCH {
return Destroyed, nil
}
return 0, newSystemError(err)
}
if c.config.Cgroups != nil && c.config.Cgroups.Freezer == configs.Frozen {
return Paused, nil
}
return Running, nil
}
func (c *linuxContainer) currentState() (*State, error) {
status, err := c.currentStatus()
if err != nil {
return nil, err
}
if status == Destroyed {
return nil, newGenericError(fmt.Errorf("container destroyed"), ContainerNotExists)
}
startTime, err := c.initProcess.startTime()
if err != nil {
return nil, newSystemError(err)
}
state := &State{
ID: c.ID(),
Config: *c.config,
InitProcessPid: c.initProcess.pid(),
InitProcessStartTime: startTime,
CgroupPaths: c.cgroupManager.GetPaths(),
NamespacePaths: make(map[configs.NamespaceType]string),
ExternalDescriptors: c.initProcess.externalDescriptors(),
}
for _, ns := range c.config.Namespaces {
state.NamespacePaths[ns.Type] = ns.GetPath(c.initProcess.pid())
}
for _, nsType := range configs.NamespaceTypes() {
if _, ok := state.NamespacePaths[nsType]; !ok {
ns := configs.Namespace{Type: nsType}
state.NamespacePaths[ns.Type] = ns.GetPath(c.initProcess.pid())
}
}
return state, nil
}