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|
// +build linux
package libpod
import (
"bufio"
"bytes"
"fmt"
"io/ioutil"
"os"
"os/exec"
"path/filepath"
"runtime"
"strconv"
"strings"
"syscall"
"time"
"github.com/containers/libpod/libpod/define"
"github.com/containers/libpod/pkg/cgroups"
"github.com/containers/libpod/pkg/errorhandling"
"github.com/containers/libpod/pkg/lookup"
"github.com/containers/libpod/pkg/rootless"
"github.com/containers/libpod/pkg/util"
"github.com/containers/libpod/utils"
pmount "github.com/containers/storage/pkg/mount"
"github.com/coreos/go-systemd/activation"
spec "github.com/opencontainers/runtime-spec/specs-go"
"github.com/opencontainers/selinux/go-selinux"
"github.com/opencontainers/selinux/go-selinux/label"
"github.com/pkg/errors"
"github.com/sirupsen/logrus"
"golang.org/x/sys/unix"
)
// ConmonOCIRuntime is an OCI runtime managed by Conmon.
// TODO: Make all calls to OCI runtime have a timeout.
type ConmonOCIRuntime struct {
name string
path string
conmonPath string
conmonEnv []string
cgroupManager string
tmpDir string
exitsDir string
socketsDir string
logSizeMax int64
noPivot bool
reservePorts bool
supportsJSON bool
supportsNoCgroups bool
sdNotify bool
}
// Make a new Conmon-based OCI runtime with the given options.
// Conmon will wrap the given OCI runtime, which can be `runc`, `crun`, or
// any runtime with a runc-compatible CLI.
// The first path that points to a valid executable will be used.
// Deliberately private. Someone should not be able to construct this outside of
// libpod.
func newConmonOCIRuntime(name string, paths []string, conmonPath string, runtimeCfg *RuntimeConfig, supportsJSON, supportsNoCgroups bool) (OCIRuntime, error) {
if name == "" {
return nil, errors.Wrapf(define.ErrInvalidArg, "the OCI runtime must be provided a non-empty name")
}
runtime := new(ConmonOCIRuntime)
runtime.name = name
runtime.conmonPath = conmonPath
runtime.conmonEnv = runtimeCfg.ConmonEnvVars
runtime.cgroupManager = runtimeCfg.CgroupManager
runtime.tmpDir = runtimeCfg.TmpDir
runtime.logSizeMax = runtimeCfg.MaxLogSize
runtime.noPivot = runtimeCfg.NoPivotRoot
runtime.reservePorts = runtimeCfg.EnablePortReservation
runtime.sdNotify = runtimeCfg.SDNotify
// TODO: probe OCI runtime for feature and enable automatically if
// available.
runtime.supportsJSON = supportsJSON
runtime.supportsNoCgroups = supportsNoCgroups
foundPath := false
for _, path := range paths {
stat, err := os.Stat(path)
if err != nil {
if os.IsNotExist(err) {
continue
}
return nil, errors.Wrapf(err, "cannot stat %s", path)
}
if !stat.Mode().IsRegular() {
continue
}
foundPath = true
runtime.path = path
logrus.Debugf("using runtime %q", path)
break
}
// Search the $PATH as last fallback
if !foundPath {
if foundRuntime, err := exec.LookPath(name); err == nil {
foundPath = true
runtime.path = foundRuntime
logrus.Debugf("using runtime %q from $PATH: %q", name, foundRuntime)
}
}
if !foundPath {
return nil, errors.Wrapf(define.ErrInvalidArg, "no valid executable found for OCI runtime %s", name)
}
runtime.exitsDir = filepath.Join(runtime.tmpDir, "exits")
runtime.socketsDir = filepath.Join(runtime.tmpDir, "socket")
if runtime.cgroupManager != CgroupfsCgroupsManager && runtime.cgroupManager != SystemdCgroupsManager {
return nil, errors.Wrapf(define.ErrInvalidArg, "invalid cgroup manager specified: %s", runtime.cgroupManager)
}
// Create the exit files and attach sockets directories
if err := os.MkdirAll(runtime.exitsDir, 0750); err != nil {
// The directory is allowed to exist
if !os.IsExist(err) {
return nil, errors.Wrapf(err, "error creating OCI runtime exit files directory %s",
runtime.exitsDir)
}
}
if err := os.MkdirAll(runtime.socketsDir, 0750); err != nil {
// The directory is allowed to exist
if !os.IsExist(err) {
return nil, errors.Wrapf(err, "error creating OCI runtime attach sockets directory %s",
runtime.socketsDir)
}
}
return runtime, nil
}
// Name returns the name of the runtime being wrapped by Conmon.
func (r *ConmonOCIRuntime) Name() string {
return r.name
}
// Path returns the path of the OCI runtime being wrapped by Conmon.
func (r *ConmonOCIRuntime) Path() string {
return r.path
}
// CreateContainer creates a container.
func (r *ConmonOCIRuntime) CreateContainer(ctr *Container, restoreOptions *ContainerCheckpointOptions) (err error) {
if len(ctr.config.IDMappings.UIDMap) != 0 || len(ctr.config.IDMappings.GIDMap) != 0 {
for _, i := range []string{ctr.state.RunDir, ctr.runtime.config.TmpDir, ctr.config.StaticDir, ctr.state.Mountpoint, ctr.runtime.config.VolumePath} {
if err := makeAccessible(i, ctr.RootUID(), ctr.RootGID()); err != nil {
return err
}
}
// if we are running a non privileged container, be sure to umount some kernel paths so they are not
// bind mounted inside the container at all.
if !ctr.config.Privileged && !rootless.IsRootless() {
ch := make(chan error)
go func() {
runtime.LockOSThread()
err := func() error {
fd, err := os.Open(fmt.Sprintf("/proc/%d/task/%d/ns/mnt", os.Getpid(), unix.Gettid()))
if err != nil {
return err
}
defer errorhandling.CloseQuiet(fd)
// create a new mountns on the current thread
if err = unix.Unshare(unix.CLONE_NEWNS); err != nil {
return err
}
defer func() {
if err := unix.Setns(int(fd.Fd()), unix.CLONE_NEWNS); err != nil {
logrus.Errorf("unable to clone new namespace: %q", err)
}
}()
// don't spread our mounts around. We are setting only /sys to be slave
// so that the cleanup process is still able to umount the storage and the
// changes are propagated to the host.
err = unix.Mount("/sys", "/sys", "none", unix.MS_REC|unix.MS_SLAVE, "")
if err != nil {
return errors.Wrapf(err, "cannot make /sys slave")
}
mounts, err := pmount.GetMounts()
if err != nil {
return err
}
for _, m := range mounts {
if !strings.HasPrefix(m.Mountpoint, "/sys/kernel") {
continue
}
err = unix.Unmount(m.Mountpoint, 0)
if err != nil && !os.IsNotExist(err) {
return errors.Wrapf(err, "cannot unmount %s", m.Mountpoint)
}
}
return r.createOCIContainer(ctr, restoreOptions)
}()
ch <- err
}()
err := <-ch
return err
}
}
return r.createOCIContainer(ctr, restoreOptions)
}
// UpdateContainerStatus retrieves the current status of the container from the
// runtime. It updates the container's state but does not save it.
// If useRuntime is false, we will not directly hit runc to see the container's
// status, but will instead only check for the existence of the conmon exit file
// and update state to stopped if it exists.
func (r *ConmonOCIRuntime) UpdateContainerStatus(ctr *Container) error {
exitFile, err := r.ExitFilePath(ctr)
if err != nil {
return err
}
runtimeDir, err := util.GetRuntimeDir()
if err != nil {
return err
}
// Store old state so we know if we were already stopped
oldState := ctr.state.State
state := new(spec.State)
cmd := exec.Command(r.path, "state", ctr.ID())
cmd.Env = append(cmd.Env, fmt.Sprintf("XDG_RUNTIME_DIR=%s", runtimeDir))
outPipe, err := cmd.StdoutPipe()
if err != nil {
return errors.Wrapf(err, "getting stdout pipe")
}
errPipe, err := cmd.StderrPipe()
if err != nil {
return errors.Wrapf(err, "getting stderr pipe")
}
if err := cmd.Start(); err != nil {
out, err2 := ioutil.ReadAll(errPipe)
if err2 != nil {
return errors.Wrapf(err, "error getting container %s state", ctr.ID())
}
if strings.Contains(string(out), "does not exist") {
if err := ctr.removeConmonFiles(); err != nil {
logrus.Debugf("unable to remove conmon files for container %s", ctr.ID())
}
ctr.state.ExitCode = -1
ctr.state.FinishedTime = time.Now()
ctr.state.State = define.ContainerStateExited
return nil
}
return errors.Wrapf(err, "error getting container %s state. stderr/out: %s", ctr.ID(), out)
}
defer func() {
_ = cmd.Wait()
}()
if err := errPipe.Close(); err != nil {
return err
}
out, err := ioutil.ReadAll(outPipe)
if err != nil {
return errors.Wrapf(err, "error reading stdout: %s", ctr.ID())
}
if err := json.NewDecoder(bytes.NewBuffer(out)).Decode(state); err != nil {
return errors.Wrapf(err, "error decoding container status for container %s", ctr.ID())
}
ctr.state.PID = state.Pid
switch state.Status {
case "created":
ctr.state.State = define.ContainerStateCreated
case "paused":
ctr.state.State = define.ContainerStatePaused
case "running":
ctr.state.State = define.ContainerStateRunning
case "stopped":
ctr.state.State = define.ContainerStateStopped
default:
return errors.Wrapf(define.ErrInternal, "unrecognized status returned by runtime for container %s: %s",
ctr.ID(), state.Status)
}
// Only grab exit status if we were not already stopped
// If we were, it should already be in the database
if ctr.state.State == define.ContainerStateStopped && oldState != define.ContainerStateStopped {
var fi os.FileInfo
chWait := make(chan error)
defer close(chWait)
_, err := WaitForFile(exitFile, chWait, time.Second*5)
if err == nil {
fi, err = os.Stat(exitFile)
}
if err != nil {
ctr.state.ExitCode = -1
ctr.state.FinishedTime = time.Now()
logrus.Errorf("No exit file for container %s found: %v", ctr.ID(), err)
return nil
}
return ctr.handleExitFile(exitFile, fi)
}
return nil
}
// StartContainer starts the given container.
// Sets time the container was started, but does not save it.
func (r *ConmonOCIRuntime) StartContainer(ctr *Container) error {
// TODO: streams should probably *not* be our STDIN/OUT/ERR - redirect to buffers?
runtimeDir, err := util.GetRuntimeDir()
if err != nil {
return err
}
env := []string{fmt.Sprintf("XDG_RUNTIME_DIR=%s", runtimeDir)}
if notify, ok := os.LookupEnv("NOTIFY_SOCKET"); ok {
env = append(env, fmt.Sprintf("NOTIFY_SOCKET=%s", notify))
}
if err := utils.ExecCmdWithStdStreams(os.Stdin, os.Stdout, os.Stderr, env, r.path, "start", ctr.ID()); err != nil {
return err
}
ctr.state.StartedTime = time.Now()
return nil
}
// KillContainer sends the given signal to the given container.
// If all is set, send to all PIDs in the container.
// All is only supported if the container created cgroups.
func (r *ConmonOCIRuntime) KillContainer(ctr *Container, signal uint, all bool) error {
logrus.Debugf("Sending signal %d to container %s", signal, ctr.ID())
runtimeDir, err := util.GetRuntimeDir()
if err != nil {
return err
}
env := []string{fmt.Sprintf("XDG_RUNTIME_DIR=%s", runtimeDir)}
var args []string
if all {
args = []string{"kill", "--all", ctr.ID(), fmt.Sprintf("%d", signal)}
} else {
args = []string{"kill", ctr.ID(), fmt.Sprintf("%d", signal)}
}
if err := utils.ExecCmdWithStdStreams(os.Stdin, os.Stdout, os.Stderr, env, r.path, args...); err != nil {
return errors.Wrapf(err, "error sending signal to container %s", ctr.ID())
}
return nil
}
// StopContainer stops a container, first using its given stop signal (or
// SIGTERM if no signal was specified), then using SIGKILL.
// Timeout is given in seconds. If timeout is 0, the container will be
// immediately kill with SIGKILL.
// Does not set finished time for container, assumes you will run updateStatus
// after to pull the exit code.
func (r *ConmonOCIRuntime) StopContainer(ctr *Container, timeout uint, all bool) error {
logrus.Debugf("Stopping container %s (PID %d)", ctr.ID(), ctr.state.PID)
// Ping the container to see if it's alive
// If it's not, it's already stopped, return
err := unix.Kill(ctr.state.PID, 0)
if err == unix.ESRCH {
return nil
}
stopSignal := ctr.config.StopSignal
if stopSignal == 0 {
stopSignal = uint(syscall.SIGTERM)
}
if timeout > 0 {
if err := r.KillContainer(ctr, stopSignal, all); err != nil {
// Is the container gone?
// If so, it probably died between the first check and
// our sending the signal
// The container is stopped, so exit cleanly
err := unix.Kill(ctr.state.PID, 0)
if err == unix.ESRCH {
return nil
}
return err
}
if err := waitContainerStop(ctr, time.Duration(timeout)*time.Second); err != nil {
logrus.Warnf("Timed out stopping container %s, resorting to SIGKILL", ctr.ID())
} else {
// No error, the container is dead
return nil
}
}
if err := r.KillContainer(ctr, 9, all); err != nil {
// Again, check if the container is gone. If it is, exit cleanly.
err := unix.Kill(ctr.state.PID, 0)
if err == unix.ESRCH {
return nil
}
return errors.Wrapf(err, "error sending SIGKILL to container %s", ctr.ID())
}
// Give runtime a few seconds to make it happen
if err := waitContainerStop(ctr, killContainerTimeout); err != nil {
return err
}
return nil
}
// DeleteContainer deletes a container from the OCI runtime.
func (r *ConmonOCIRuntime) DeleteContainer(ctr *Container) error {
runtimeDir, err := util.GetRuntimeDir()
if err != nil {
return err
}
env := []string{fmt.Sprintf("XDG_RUNTIME_DIR=%s", runtimeDir)}
return utils.ExecCmdWithStdStreams(os.Stdin, os.Stdout, os.Stderr, env, r.path, "delete", "--force", ctr.ID())
}
// PauseContainer pauses the given container.
func (r *ConmonOCIRuntime) PauseContainer(ctr *Container) error {
runtimeDir, err := util.GetRuntimeDir()
if err != nil {
return err
}
env := []string{fmt.Sprintf("XDG_RUNTIME_DIR=%s", runtimeDir)}
return utils.ExecCmdWithStdStreams(os.Stdin, os.Stdout, os.Stderr, env, r.path, "pause", ctr.ID())
}
// UnpauseContainer unpauses the given container.
func (r *ConmonOCIRuntime) UnpauseContainer(ctr *Container) error {
runtimeDir, err := util.GetRuntimeDir()
if err != nil {
return err
}
env := []string{fmt.Sprintf("XDG_RUNTIME_DIR=%s", runtimeDir)}
return utils.ExecCmdWithStdStreams(os.Stdin, os.Stdout, os.Stderr, env, r.path, "resume", ctr.ID())
}
// ExecContainer executes a command in a running container
// TODO: Split into Create/Start/Attach/Wait
func (r *ConmonOCIRuntime) ExecContainer(c *Container, sessionID string, options *ExecOptions) (int, chan error, error) {
if options == nil {
return -1, nil, errors.Wrapf(define.ErrInvalidArg, "must provide an ExecOptions struct to ExecContainer")
}
if len(options.Cmd) == 0 {
return -1, nil, errors.Wrapf(define.ErrInvalidArg, "must provide a command to execute")
}
if sessionID == "" {
return -1, nil, errors.Wrapf(define.ErrEmptyID, "must provide a session ID for exec")
}
// create sync pipe to receive the pid
parentSyncPipe, childSyncPipe, err := newPipe()
if err != nil {
return -1, nil, errors.Wrapf(err, "error creating socket pair")
}
defer errorhandling.CloseQuiet(parentSyncPipe)
// create start pipe to set the cgroup before running
// attachToExec is responsible for closing parentStartPipe
childStartPipe, parentStartPipe, err := newPipe()
if err != nil {
return -1, nil, errors.Wrapf(err, "error creating socket pair")
}
// We want to make sure we close the parent{Start,Attach}Pipes if we fail
// but also don't want to close them after attach to exec is called
attachToExecCalled := false
defer func() {
if !attachToExecCalled {
errorhandling.CloseQuiet(parentStartPipe)
}
}()
// create the attach pipe to allow attach socket to be created before
// $RUNTIME exec starts running. This is to make sure we can capture all output
// from the process through that socket, rather than half reading the log, half attaching to the socket
// attachToExec is responsible for closing parentAttachPipe
parentAttachPipe, childAttachPipe, err := newPipe()
if err != nil {
return -1, nil, errors.Wrapf(err, "error creating socket pair")
}
defer func() {
if !attachToExecCalled {
errorhandling.CloseQuiet(parentAttachPipe)
}
}()
childrenClosed := false
defer func() {
if !childrenClosed {
errorhandling.CloseQuiet(childSyncPipe)
errorhandling.CloseQuiet(childAttachPipe)
errorhandling.CloseQuiet(childStartPipe)
}
}()
runtimeDir, err := util.GetRuntimeDir()
if err != nil {
return -1, nil, err
}
finalEnv := make([]string, 0, len(options.Env))
for k, v := range options.Env {
finalEnv = append(finalEnv, fmt.Sprintf("%s=%s", k, v))
}
processFile, err := prepareProcessExec(c, options.Cmd, finalEnv, options.Terminal, options.Cwd, options.User, sessionID)
if err != nil {
return -1, nil, err
}
var ociLog string
if logrus.GetLevel() != logrus.DebugLevel && r.supportsJSON {
ociLog = c.execOCILog(sessionID)
}
args := r.sharedConmonArgs(c, sessionID, c.execBundlePath(sessionID), c.execPidPath(sessionID), c.execLogPath(sessionID), c.execExitFileDir(sessionID), ociLog)
if options.PreserveFDs > 0 {
args = append(args, formatRuntimeOpts("--preserve-fds", fmt.Sprintf("%d", options.PreserveFDs))...)
}
for _, capability := range options.CapAdd {
args = append(args, formatRuntimeOpts("--cap", capability)...)
}
if options.Terminal {
args = append(args, "-t")
}
// Append container ID and command
args = append(args, "-e")
// TODO make this optional when we can detach
args = append(args, "--exec-attach")
args = append(args, "--exec-process-spec", processFile.Name())
logrus.WithFields(logrus.Fields{
"args": args,
}).Debugf("running conmon: %s", r.conmonPath)
execCmd := exec.Command(r.conmonPath, args...)
if options.Streams != nil {
if options.Streams.AttachInput {
execCmd.Stdin = options.Streams.InputStream
}
if options.Streams.AttachOutput {
execCmd.Stdout = options.Streams.OutputStream
}
if options.Streams.AttachError {
execCmd.Stderr = options.Streams.ErrorStream
}
}
conmonEnv, extraFiles, err := r.configureConmonEnv(runtimeDir)
if err != nil {
return -1, nil, err
}
if options.PreserveFDs > 0 {
for fd := 3; fd < int(3+options.PreserveFDs); fd++ {
execCmd.ExtraFiles = append(execCmd.ExtraFiles, os.NewFile(uintptr(fd), fmt.Sprintf("fd-%d", fd)))
}
}
// we don't want to step on users fds they asked to preserve
// Since 0-2 are used for stdio, start the fds we pass in at preserveFDs+3
execCmd.Env = append(r.conmonEnv, fmt.Sprintf("_OCI_SYNCPIPE=%d", options.PreserveFDs+3), fmt.Sprintf("_OCI_STARTPIPE=%d", options.PreserveFDs+4), fmt.Sprintf("_OCI_ATTACHPIPE=%d", options.PreserveFDs+5))
execCmd.Env = append(execCmd.Env, conmonEnv...)
execCmd.ExtraFiles = append(execCmd.ExtraFiles, childSyncPipe, childStartPipe, childAttachPipe)
execCmd.ExtraFiles = append(execCmd.ExtraFiles, extraFiles...)
execCmd.Dir = c.execBundlePath(sessionID)
execCmd.SysProcAttr = &syscall.SysProcAttr{
Setpgid: true,
}
err = startCommandGivenSelinux(execCmd)
// We don't need children pipes on the parent side
errorhandling.CloseQuiet(childSyncPipe)
errorhandling.CloseQuiet(childAttachPipe)
errorhandling.CloseQuiet(childStartPipe)
childrenClosed = true
if err != nil {
return -1, nil, errors.Wrapf(err, "cannot start container %s", c.ID())
}
if err := r.moveConmonToCgroupAndSignal(c, execCmd, parentStartPipe); err != nil {
return -1, nil, err
}
if options.PreserveFDs > 0 {
for fd := 3; fd < int(3+options.PreserveFDs); fd++ {
// These fds were passed down to the runtime. Close them
// and not interfere
if err := os.NewFile(uintptr(fd), fmt.Sprintf("fd-%d", fd)).Close(); err != nil {
logrus.Debugf("unable to close file fd-%d", fd)
}
}
}
// TODO Only create if !detach
// Attach to the container before starting it
attachChan := make(chan error)
go func() {
// attachToExec is responsible for closing pipes
attachChan <- c.attachToExec(options.Streams, options.DetachKeys, options.Resize, sessionID, parentStartPipe, parentAttachPipe)
close(attachChan)
}()
attachToExecCalled = true
pid, err := readConmonPipeData(parentSyncPipe, ociLog)
return pid, attachChan, err
}
// ExecStopContainer stops a given exec session in a running container.
func (r *ConmonOCIRuntime) ExecStopContainer(ctr *Container, sessionID string, timeout uint) error {
session, ok := ctr.state.ExecSessions[sessionID]
if !ok {
// TODO This should probably be a separate error
return errors.Wrapf(define.ErrInvalidArg, "no exec session with ID %s found in container %s", sessionID, ctr.ID())
}
logrus.Debugf("Going to stop container %s exec session %s", ctr.ID(), sessionID)
// Is the session dead?
// Ping the PID with signal 0 to see if it still exists.
if err := unix.Kill(session.PID, 0); err != nil {
if err == unix.ESRCH {
return nil
}
return errors.Wrapf(err, "error pinging container %s exec session %s PID %d with signal 0", ctr.ID(), sessionID, session.PID)
}
if timeout > 0 {
// Use SIGTERM by default, then SIGSTOP after timeout.
logrus.Debugf("Killing exec session %s (PID %d) of container %s with SIGTERM", sessionID, session.PID, ctr.ID())
if err := unix.Kill(session.PID, unix.SIGTERM); err != nil {
if err == unix.ESRCH {
return nil
}
return errors.Wrapf(err, "error killing container %s exec session %s PID %d with SIGTERM", ctr.ID(), sessionID, session.PID)
}
// Wait for the PID to stop
if err := waitPidStop(session.PID, time.Duration(timeout)*time.Second); err != nil {
logrus.Warnf("Timed out waiting for container %s exec session %s to stop, resorting to SIGKILL", ctr.ID(), sessionID)
} else {
// No error, container is dead
return nil
}
}
// SIGTERM did not work. On to SIGKILL.
logrus.Debugf("Killing exec session %s (PID %d) of container %s with SIGKILL", sessionID, session.PID, ctr.ID())
if err := unix.Kill(session.PID, unix.SIGTERM); err != nil {
if err == unix.ESRCH {
return nil
}
return errors.Wrapf(err, "error killing container %s exec session %s PID %d with SIGKILL", ctr.ID(), sessionID, session.PID)
}
// Wait for the PID to stop
if err := waitPidStop(session.PID, killContainerTimeout*time.Second); err != nil {
return errors.Wrapf(err, "timed out waiting for container %s exec session %s PID %d to stop after SIGKILL", ctr.ID(), sessionID, session.PID)
}
return nil
}
// ExecCleanupContainer cleans up files created when a command is run via
// ExecContainer. This includes the attach socket for the exec session.
func (r *ConmonOCIRuntime) ExecContainerCleanup(ctr *Container, sessionID string) error {
// Clean up the sockets dir. Issue #3962
// Also ignore if it doesn't exist for some reason; hence the conditional return below
if err := os.RemoveAll(filepath.Join(r.socketsDir, sessionID)); err != nil && !os.IsNotExist(err) {
return err
}
return nil
}
// CheckpointContainer checkpoints the given container.
func (r *ConmonOCIRuntime) CheckpointContainer(ctr *Container, options ContainerCheckpointOptions) error {
if err := label.SetSocketLabel(ctr.ProcessLabel()); err != nil {
return err
}
// imagePath is used by CRIU to store the actual checkpoint files
imagePath := ctr.CheckpointPath()
// workPath will be used to store dump.log and stats-dump
workPath := ctr.bundlePath()
logrus.Debugf("Writing checkpoint to %s", imagePath)
logrus.Debugf("Writing checkpoint logs to %s", workPath)
args := []string{}
args = append(args, "checkpoint")
args = append(args, "--image-path")
args = append(args, imagePath)
args = append(args, "--work-path")
args = append(args, workPath)
if options.KeepRunning {
args = append(args, "--leave-running")
}
if options.TCPEstablished {
args = append(args, "--tcp-established")
}
args = append(args, ctr.ID())
return utils.ExecCmdWithStdStreams(os.Stdin, os.Stdout, os.Stderr, nil, r.path, args...)
}
// SupportsCheckpoint checks if the OCI runtime supports checkpointing
// containers.
func (r *ConmonOCIRuntime) SupportsCheckpoint() bool {
// Check if the runtime implements checkpointing. Currently only
// runc's checkpoint/restore implementation is supported.
cmd := exec.Command(r.path, "checkpoint", "-h")
if err := cmd.Start(); err != nil {
return false
}
if err := cmd.Wait(); err == nil {
return true
}
return false
}
// SupportsJSONErrors checks if the OCI runtime supports JSON-formatted error
// messages.
func (r *ConmonOCIRuntime) SupportsJSONErrors() bool {
return r.supportsJSON
}
// SupportsNoCgroups checks if the OCI runtime supports running containers
// without cgroups (the --cgroup-manager=disabled flag).
func (r *ConmonOCIRuntime) SupportsNoCgroups() bool {
return r.supportsNoCgroups
}
// AttachSocketPath is the path to a single container's attach socket.
func (r *ConmonOCIRuntime) AttachSocketPath(ctr *Container) (string, error) {
if ctr == nil {
return "", errors.Wrapf(define.ErrInvalidArg, "must provide a valid container to get attach socket path")
}
return filepath.Join(r.socketsDir, ctr.ID(), "attach"), nil
}
// ExecAttachSocketPath is the path to a container's exec session attach socket.
func (r *ConmonOCIRuntime) ExecAttachSocketPath(ctr *Container, sessionID string) (string, error) {
// We don't even use container, so don't validity check it
if sessionID == "" {
return "", errors.Wrapf(define.ErrInvalidArg, "must provide a valid session ID to get attach socket path")
}
return filepath.Join(r.socketsDir, sessionID, "attach"), nil
}
// ExitFilePath is the path to a container's exit file.
func (r *ConmonOCIRuntime) ExitFilePath(ctr *Container) (string, error) {
if ctr == nil {
return "", errors.Wrapf(define.ErrInvalidArg, "must provide a valid container to get exit file path")
}
return filepath.Join(r.exitsDir, ctr.ID()), nil
}
// RuntimeInfo provides information on the runtime.
func (r *ConmonOCIRuntime) RuntimeInfo() (map[string]interface{}, error) {
runtimePackage := packageVersion(r.path)
conmonPackage := packageVersion(r.conmonPath)
runtimeVersion, err := r.getOCIRuntimeVersion()
if err != nil {
return nil, errors.Wrapf(err, "error getting version of OCI runtime %s", r.name)
}
conmonVersion, err := r.getConmonVersion()
if err != nil {
return nil, errors.Wrapf(err, "error getting conmon version")
}
info := make(map[string]interface{})
info["Conmon"] = map[string]interface{}{
"path": r.conmonPath,
"package": conmonPackage,
"version": conmonVersion,
}
info["OCIRuntime"] = map[string]interface{}{
"name": r.name,
"path": r.path,
"package": runtimePackage,
"version": runtimeVersion,
}
return info, nil
}
// makeAccessible changes the path permission and each parent directory to have --x--x--x
func makeAccessible(path string, uid, gid int) error {
for ; path != "/"; path = filepath.Dir(path) {
st, err := os.Stat(path)
if err != nil {
if os.IsNotExist(err) {
return nil
}
return err
}
if int(st.Sys().(*syscall.Stat_t).Uid) == uid && int(st.Sys().(*syscall.Stat_t).Gid) == gid {
continue
}
if st.Mode()&0111 != 0111 {
if err := os.Chmod(path, st.Mode()|0111); err != nil {
return err
}
}
}
return nil
}
// Wait for a container which has been sent a signal to stop
func waitContainerStop(ctr *Container, timeout time.Duration) error {
return waitPidStop(ctr.state.PID, timeout)
}
// Wait for a given PID to stop
func waitPidStop(pid int, timeout time.Duration) error {
done := make(chan struct{})
chControl := make(chan struct{})
go func() {
for {
select {
case <-chControl:
return
default:
if err := unix.Kill(pid, 0); err != nil {
if err == unix.ESRCH {
close(done)
return
}
logrus.Errorf("Error pinging PID %d with signal 0: %v", pid, err)
}
time.Sleep(100 * time.Millisecond)
}
}
}()
select {
case <-done:
return nil
case <-time.After(timeout):
close(chControl)
return errors.Errorf("given PIDs did not die within timeout")
}
}
// createOCIContainer generates this container's main conmon instance and prepares it for starting
func (r *ConmonOCIRuntime) createOCIContainer(ctr *Container, restoreOptions *ContainerCheckpointOptions) (err error) {
var stderrBuf bytes.Buffer
runtimeDir, err := util.GetRuntimeDir()
if err != nil {
return err
}
parentSyncPipe, childSyncPipe, err := newPipe()
if err != nil {
return errors.Wrapf(err, "error creating socket pair")
}
defer errorhandling.CloseQuiet(parentSyncPipe)
childStartPipe, parentStartPipe, err := newPipe()
if err != nil {
return errors.Wrapf(err, "error creating socket pair for start pipe")
}
defer errorhandling.CloseQuiet(parentStartPipe)
var ociLog string
if logrus.GetLevel() != logrus.DebugLevel && r.supportsJSON {
ociLog = filepath.Join(ctr.state.RunDir, "oci-log")
}
args := r.sharedConmonArgs(ctr, ctr.ID(), ctr.bundlePath(), filepath.Join(ctr.state.RunDir, "pidfile"), ctr.LogPath(), r.exitsDir, ociLog)
if ctr.config.Spec.Process.Terminal {
args = append(args, "-t")
} else if ctr.config.Stdin {
args = append(args, "-i")
}
if ctr.config.ConmonPidFile != "" {
args = append(args, "--conmon-pidfile", ctr.config.ConmonPidFile)
}
if r.noPivot {
args = append(args, "--no-pivot")
}
if len(ctr.config.ExitCommand) > 0 {
args = append(args, "--exit-command", ctr.config.ExitCommand[0])
for _, arg := range ctr.config.ExitCommand[1:] {
args = append(args, []string{"--exit-command-arg", arg}...)
}
}
if restoreOptions != nil {
args = append(args, "--restore", ctr.CheckpointPath())
if restoreOptions.TCPEstablished {
args = append(args, "--runtime-opt", "--tcp-established")
}
}
logrus.WithFields(logrus.Fields{
"args": args,
}).Debugf("running conmon: %s", r.conmonPath)
cmd := exec.Command(r.conmonPath, args...)
cmd.Dir = ctr.bundlePath()
cmd.SysProcAttr = &syscall.SysProcAttr{
Setpgid: true,
}
// TODO this is probably a really bad idea for some uses
// Make this configurable
cmd.Stdin = os.Stdin
cmd.Stdout = os.Stdout
cmd.Stderr = os.Stderr
if ctr.config.Spec.Process.Terminal {
cmd.Stderr = &stderrBuf
}
// 0, 1 and 2 are stdin, stdout and stderr
conmonEnv, envFiles, err := r.configureConmonEnv(runtimeDir)
if err != nil {
return err
}
cmd.Env = append(r.conmonEnv, fmt.Sprintf("_OCI_SYNCPIPE=%d", 3), fmt.Sprintf("_OCI_STARTPIPE=%d", 4))
cmd.Env = append(cmd.Env, conmonEnv...)
cmd.ExtraFiles = append(cmd.ExtraFiles, childSyncPipe, childStartPipe)
cmd.ExtraFiles = append(cmd.ExtraFiles, envFiles...)
if r.reservePorts && !ctr.config.NetMode.IsSlirp4netns() {
ports, err := bindPorts(ctr.config.PortMappings)
if err != nil {
return err
}
// Leak the port we bound in the conmon process. These fd's won't be used
// by the container and conmon will keep the ports busy so that another
// process cannot use them.
cmd.ExtraFiles = append(cmd.ExtraFiles, ports...)
}
if ctr.config.NetMode.IsSlirp4netns() {
if ctr.config.PostConfigureNetNS {
ctr.rootlessSlirpSyncR, ctr.rootlessSlirpSyncW, err = os.Pipe()
if err != nil {
return errors.Wrapf(err, "failed to create rootless network sync pipe")
}
} else {
if ctr.rootlessSlirpSyncR != nil {
defer errorhandling.CloseQuiet(ctr.rootlessSlirpSyncR)
}
if ctr.rootlessSlirpSyncW != nil {
defer errorhandling.CloseQuiet(ctr.rootlessSlirpSyncW)
}
}
// Leak one end in conmon, the other one will be leaked into slirp4netns
cmd.ExtraFiles = append(cmd.ExtraFiles, ctr.rootlessSlirpSyncW)
}
err = startCommandGivenSelinux(cmd)
// regardless of whether we errored or not, we no longer need the children pipes
childSyncPipe.Close()
childStartPipe.Close()
if err != nil {
return err
}
if err := r.moveConmonToCgroupAndSignal(ctr, cmd, parentStartPipe); err != nil {
return err
}
/* Wait for initial setup and fork, and reap child */
err = cmd.Wait()
if err != nil {
return err
}
pid, err := readConmonPipeData(parentSyncPipe, ociLog)
if err != nil {
if err2 := r.DeleteContainer(ctr); err2 != nil {
logrus.Errorf("Error removing container %s from runtime after creation failed", ctr.ID())
}
return err
}
ctr.state.PID = pid
conmonPID, err := readConmonPidFile(ctr.config.ConmonPidFile)
if err != nil {
logrus.Warnf("error reading conmon pid file for container %s: %s", ctr.ID(), err.Error())
} else if conmonPID > 0 {
// conmon not having a pid file is a valid state, so don't set it if we don't have it
logrus.Infof("Got Conmon PID as %d", conmonPID)
ctr.state.ConmonPID = conmonPID
}
return nil
}
// prepareProcessExec returns the path of the process.json used in runc exec -p
// caller is responsible to close the returned *os.File if needed.
func prepareProcessExec(c *Container, cmd, env []string, tty bool, cwd, user, sessionID string) (*os.File, error) {
f, err := ioutil.TempFile(c.execBundlePath(sessionID), "exec-process-")
if err != nil {
return nil, err
}
pspec := c.config.Spec.Process
pspec.SelinuxLabel = c.config.ProcessLabel
pspec.Args = cmd
// We need to default this to false else it will inherit terminal as true
// from the container.
pspec.Terminal = false
if tty {
pspec.Terminal = true
}
if len(env) > 0 {
pspec.Env = append(pspec.Env, env...)
}
if cwd != "" {
pspec.Cwd = cwd
}
overrides := c.getUserOverrides()
execUser, err := lookup.GetUserGroupInfo(c.state.Mountpoint, user, overrides)
if err != nil {
return nil, err
}
// If user was set, look it up in the container to get a UID to use on
// the host
if user != "" {
sgids := make([]uint32, 0, len(execUser.Sgids))
for _, sgid := range execUser.Sgids {
sgids = append(sgids, uint32(sgid))
}
processUser := spec.User{
UID: uint32(execUser.Uid),
GID: uint32(execUser.Gid),
AdditionalGids: sgids,
}
pspec.User = processUser
}
hasHomeSet := false
for _, s := range pspec.Env {
if strings.HasPrefix(s, "HOME=") {
hasHomeSet = true
break
}
}
if !hasHomeSet {
pspec.Env = append(pspec.Env, fmt.Sprintf("HOME=%s", execUser.Home))
}
processJSON, err := json.Marshal(pspec)
if err != nil {
return nil, err
}
if err := ioutil.WriteFile(f.Name(), processJSON, 0644); err != nil {
return nil, err
}
return f, nil
}
// configureConmonEnv gets the environment values to add to conmon's exec struct
// TODO this may want to be less hardcoded/more configurable in the future
func (r *ConmonOCIRuntime) configureConmonEnv(runtimeDir string) ([]string, []*os.File, error) {
env := make([]string, 0, 6)
env = append(env, fmt.Sprintf("XDG_RUNTIME_DIR=%s", runtimeDir))
env = append(env, fmt.Sprintf("_CONTAINERS_USERNS_CONFIGURED=%s", os.Getenv("_CONTAINERS_USERNS_CONFIGURED")))
env = append(env, fmt.Sprintf("_CONTAINERS_ROOTLESS_UID=%s", os.Getenv("_CONTAINERS_ROOTLESS_UID")))
home, err := homeDir()
if err != nil {
return nil, nil, err
}
env = append(env, fmt.Sprintf("HOME=%s", home))
extraFiles := make([]*os.File, 0)
if notify, ok := os.LookupEnv("NOTIFY_SOCKET"); ok {
env = append(env, fmt.Sprintf("NOTIFY_SOCKET=%s", notify))
}
if !r.sdNotify {
if listenfds, ok := os.LookupEnv("LISTEN_FDS"); ok {
env = append(env, fmt.Sprintf("LISTEN_FDS=%s", listenfds), "LISTEN_PID=1")
fds := activation.Files(false)
extraFiles = append(extraFiles, fds...)
}
} else {
logrus.Debug("disabling SD notify")
}
return env, extraFiles, nil
}
// sharedConmonArgs takes common arguments for exec and create/restore and formats them for the conmon CLI
func (r *ConmonOCIRuntime) sharedConmonArgs(ctr *Container, cuuid, bundlePath, pidPath, logPath, exitDir, ociLogPath string) []string {
// set the conmon API version to be able to use the correct sync struct keys
args := []string{"--api-version", "1"}
if r.cgroupManager == SystemdCgroupsManager && !ctr.config.NoCgroups {
args = append(args, "-s")
}
args = append(args, "-c", ctr.ID())
args = append(args, "-u", cuuid)
args = append(args, "-r", r.path)
args = append(args, "-b", bundlePath)
args = append(args, "-p", pidPath)
var logDriver string
switch ctr.LogDriver() {
case JournaldLogging:
logDriver = JournaldLogging
case JSONLogging:
fallthrough
default: //nolint-stylecheck
// No case here should happen except JSONLogging, but keep this here in case the options are extended
logrus.Errorf("%s logging specified but not supported. Choosing k8s-file logging instead", ctr.LogDriver())
fallthrough
case "":
// to get here, either a user would specify `--log-driver ""`, or this came from another place in libpod
// since the former case is obscure, and the latter case isn't an error, let's silently fallthrough
fallthrough
case KubernetesLogging:
logDriver = fmt.Sprintf("%s:%s", KubernetesLogging, logPath)
}
args = append(args, "-l", logDriver)
args = append(args, "--exit-dir", exitDir)
args = append(args, "--socket-dir-path", r.socketsDir)
if r.logSizeMax >= 0 {
args = append(args, "--log-size-max", fmt.Sprintf("%v", r.logSizeMax))
}
logLevel := logrus.GetLevel()
args = append(args, "--log-level", logLevel.String())
if logLevel == logrus.DebugLevel {
logrus.Debugf("%s messages will be logged to syslog", r.conmonPath)
args = append(args, "--syslog")
}
if ociLogPath != "" {
args = append(args, "--runtime-arg", "--log-format=json", "--runtime-arg", "--log", fmt.Sprintf("--runtime-arg=%s", ociLogPath))
}
if ctr.config.NoCgroups {
logrus.Debugf("Running with no CGroups")
args = append(args, "--runtime-arg", "--cgroup-manager", "--runtime-arg", "disabled")
}
return args
}
// startCommandGivenSelinux starts a container ensuring to set the labels of
// the process to make sure SELinux doesn't block conmon communication, if SELinux is enabled
func startCommandGivenSelinux(cmd *exec.Cmd) error {
if !selinux.GetEnabled() {
return cmd.Start()
}
// Set the label of the conmon process to be level :s0
// This will allow the container processes to talk to fifo-files
// passed into the container by conmon
var (
plabel string
con selinux.Context
err error
)
plabel, err = selinux.CurrentLabel()
if err != nil {
return errors.Wrapf(err, "Failed to get current SELinux label")
}
con, err = selinux.NewContext(plabel)
if err != nil {
return errors.Wrapf(err, "Failed to get new context from SELinux label")
}
runtime.LockOSThread()
if con["level"] != "s0" && con["level"] != "" {
con["level"] = "s0"
if err = label.SetProcessLabel(con.Get()); err != nil {
runtime.UnlockOSThread()
return err
}
}
err = cmd.Start()
// Ignore error returned from SetProcessLabel("") call,
// can't recover.
if labelErr := label.SetProcessLabel(""); labelErr != nil {
logrus.Errorf("unable to set process label: %q", err)
}
runtime.UnlockOSThread()
return err
}
// moveConmonToCgroupAndSignal gets a container's cgroupParent and moves the conmon process to that cgroup
// it then signals for conmon to start by sending nonse data down the start fd
func (r *ConmonOCIRuntime) moveConmonToCgroupAndSignal(ctr *Container, cmd *exec.Cmd, startFd *os.File) error {
mustCreateCgroup := true
// If cgroup creation is disabled - just signal.
if ctr.config.NoCgroups {
mustCreateCgroup = false
}
if rootless.IsRootless() {
ownsCgroup, err := cgroups.UserOwnsCurrentSystemdCgroup()
if err != nil {
return err
}
mustCreateCgroup = !ownsCgroup
}
if mustCreateCgroup {
cgroupParent := ctr.CgroupParent()
if r.cgroupManager == SystemdCgroupsManager {
unitName := createUnitName("libpod-conmon", ctr.ID())
realCgroupParent := cgroupParent
splitParent := strings.Split(cgroupParent, "/")
if strings.HasSuffix(cgroupParent, ".slice") && len(splitParent) > 1 {
realCgroupParent = splitParent[len(splitParent)-1]
}
logrus.Infof("Running conmon under slice %s and unitName %s", realCgroupParent, unitName)
if err := utils.RunUnderSystemdScope(cmd.Process.Pid, realCgroupParent, unitName); err != nil {
logrus.Warnf("Failed to add conmon to systemd sandbox cgroup: %v", err)
}
} else {
cgroupPath := filepath.Join(ctr.config.CgroupParent, "conmon")
control, err := cgroups.New(cgroupPath, &spec.LinuxResources{})
if err != nil {
logrus.Warnf("Failed to add conmon to cgroupfs sandbox cgroup: %v", err)
} else {
// we need to remove this defer and delete the cgroup once conmon exits
// maybe need a conmon monitor?
if err := control.AddPid(cmd.Process.Pid); err != nil {
logrus.Warnf("Failed to add conmon to cgroupfs sandbox cgroup: %v", err)
}
}
}
}
/* We set the cgroup, now the child can start creating children */
if err := writeConmonPipeData(startFd); err != nil {
return err
}
return nil
}
// newPipe creates a unix socket pair for communication
func newPipe() (parent *os.File, child *os.File, err error) {
fds, err := unix.Socketpair(unix.AF_LOCAL, unix.SOCK_SEQPACKET|unix.SOCK_CLOEXEC, 0)
if err != nil {
return nil, nil, err
}
return os.NewFile(uintptr(fds[1]), "parent"), os.NewFile(uintptr(fds[0]), "child"), nil
}
// readConmonPidFile attempts to read conmon's pid from its pid file
func readConmonPidFile(pidFile string) (int, error) {
// Let's try reading the Conmon pid at the same time.
if pidFile != "" {
contents, err := ioutil.ReadFile(pidFile)
if err != nil {
return -1, err
}
// Convert it to an int
conmonPID, err := strconv.Atoi(string(contents))
if err != nil {
return -1, err
}
return conmonPID, nil
}
return 0, nil
}
// readConmonPipeData attempts to read a syncInfo struct from the pipe
func readConmonPipeData(pipe *os.File, ociLog string) (int, error) {
// syncInfo is used to return data from monitor process to daemon
type syncInfo struct {
Data int `json:"data"`
Message string `json:"message,omitempty"`
}
// Wait to get container pid from conmon
type syncStruct struct {
si *syncInfo
err error
}
ch := make(chan syncStruct)
go func() {
var si *syncInfo
rdr := bufio.NewReader(pipe)
b, err := rdr.ReadBytes('\n')
if err != nil {
ch <- syncStruct{err: err}
}
if err := json.Unmarshal(b, &si); err != nil {
ch <- syncStruct{err: err}
return
}
ch <- syncStruct{si: si}
}()
data := -1
select {
case ss := <-ch:
if ss.err != nil {
if ociLog != "" {
ociLogData, err := ioutil.ReadFile(ociLog)
if err == nil {
var ociErr ociError
if err := json.Unmarshal(ociLogData, &ociErr); err == nil {
return -1, getOCIRuntimeError(ociErr.Msg)
}
}
}
return -1, errors.Wrapf(ss.err, "container create failed (no logs from conmon)")
}
logrus.Debugf("Received: %d", ss.si.Data)
if ss.si.Data < 0 {
if ociLog != "" {
ociLogData, err := ioutil.ReadFile(ociLog)
if err == nil {
var ociErr ociError
if err := json.Unmarshal(ociLogData, &ociErr); err == nil {
return ss.si.Data, getOCIRuntimeError(ociErr.Msg)
}
}
}
// If we failed to parse the JSON errors, then print the output as it is
if ss.si.Message != "" {
return ss.si.Data, getOCIRuntimeError(ss.si.Message)
}
return ss.si.Data, errors.Wrapf(define.ErrInternal, "container create failed")
}
data = ss.si.Data
case <-time.After(ContainerCreateTimeout):
return -1, errors.Wrapf(define.ErrInternal, "container creation timeout")
}
return data, nil
}
// writeConmonPipeData writes nonse data to a pipe
func writeConmonPipeData(pipe *os.File) error {
someData := []byte{0}
_, err := pipe.Write(someData)
return err
}
// formatRuntimeOpts prepends opts passed to it with --runtime-opt for passing to conmon
func formatRuntimeOpts(opts ...string) []string {
args := make([]string, 0, len(opts)*2)
for _, o := range opts {
args = append(args, "--runtime-opt", o)
}
return args
}
// getConmonVersion returns a string representation of the conmon version.
func (r *ConmonOCIRuntime) getConmonVersion() (string, error) {
output, err := utils.ExecCmd(r.conmonPath, "--version")
if err != nil {
return "", err
}
return strings.TrimSuffix(strings.Replace(output, "\n", ", ", 1), "\n"), nil
}
// getOCIRuntimeVersion returns a string representation of the OCI runtime's
// version.
func (r *ConmonOCIRuntime) getOCIRuntimeVersion() (string, error) {
output, err := utils.ExecCmd(r.path, "--version")
if err != nil {
return "", err
}
return strings.TrimSuffix(output, "\n"), nil
}
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