package daemon
import (
"encoding/json"
"errors"
"fmt"
"io"
"os"
"path/filepath"
"sync"
"syscall"
"time"
"github.com/opencontainers/runc/libcontainer/label"
"github.com/Sirupsen/logrus"
"github.com/docker/docker/daemon/execdriver"
"github.com/docker/docker/daemon/logger"
"github.com/docker/docker/daemon/logger/jsonfilelog"
"github.com/docker/docker/daemon/network"
derr "github.com/docker/docker/errors"
"github.com/docker/docker/pkg/broadcaster"
"github.com/docker/docker/pkg/fileutils"
"github.com/docker/docker/pkg/ioutils"
"github.com/docker/docker/pkg/mount"
"github.com/docker/docker/pkg/nat"
"github.com/docker/docker/pkg/promise"
"github.com/docker/docker/pkg/signal"
"github.com/docker/docker/pkg/symlink"
"github.com/docker/docker/pkg/system"
"github.com/docker/docker/runconfig"
"github.com/docker/docker/volume"
)
var (
// ErrRootFSReadOnly is returned when a container
// rootfs is marked readonly.
ErrRootFSReadOnly = errors.New("container rootfs is marked read-only")
)
type streamConfig struct {
stdout *broadcaster.Unbuffered
stderr *broadcaster.Unbuffered
stdin io.ReadCloser
stdinPipe io.WriteCloser
}
// CommonContainer holds the fields for a container which are
// applicable across all platforms supported by the daemon.
type CommonContainer struct {
streamConfig
// embed for Container to support states directly.
*State `json:"State"` // Needed for remote api version <= 1.11
root string // Path to the "home" of the container, including metadata.
basefs string // Path to the graphdriver mountpoint
ID string
Created time.Time
Path string
Args []string
Config *runconfig.Config
ImageID string `json:"Image"`
NetworkSettings *network.Settings
LogPath string
Name string
Driver string
// MountLabel contains the options for the 'mount' command
MountLabel string
ProcessLabel string
RestartCount int
HasBeenStartedBefore bool
HasBeenManuallyStopped bool // used for unless-stopped restart policy
MountPoints map[string]*volume.MountPoint
hostConfig *runconfig.HostConfig
command *execdriver.Command
monitor *containerMonitor
execCommands *execStore
// logDriver for closing
logDriver logger.Logger
logCopier *logger.Copier
}
func (container *Container) fromDisk() error {
pth, err := container.jsonPath()
if err != nil {
return err
}
jsonSource, err := os.Open(pth)
if err != nil {
return err
}
defer jsonSource.Close()
dec := json.NewDecoder(jsonSource)
// Load container settings
if err := dec.Decode(container); err != nil {
return err
}
if err := label.ReserveLabel(container.ProcessLabel); err != nil {
return err
}
return container.readHostConfig()
}
func (container *Container) toDisk() error {
pth, err := container.jsonPath()
if err != nil {
return err
}
jsonSource, err := os.Create(pth)
if err != nil {
return err
}
defer jsonSource.Close()
enc := json.NewEncoder(jsonSource)
// Save container settings
if err := enc.Encode(container); err != nil {
return err
}
return container.writeHostConfig()
}
func (container *Container) toDiskLocking() error {
container.Lock()
err := container.toDisk()
container.Unlock()
return err
}
func (container *Container) readHostConfig() error {
container.hostConfig = &runconfig.HostConfig{}
// If the hostconfig file does not exist, do not read it.
// (We still have to initialize container.hostConfig,
// but that's OK, since we just did that above.)
pth, err := container.hostConfigPath()
if err != nil {
return err
}
f, err := os.Open(pth)
if err != nil {
if os.IsNotExist(err) {
return nil
}
return err
}
defer f.Close()
return json.NewDecoder(f).Decode(&container.hostConfig)
}
func (container *Container) writeHostConfig() error {
pth, err := container.hostConfigPath()
if err != nil {
return err
}
f, err := os.Create(pth)
if err != nil {
return err
}
defer f.Close()
return json.NewEncoder(f).Encode(&container.hostConfig)
}
// GetResourcePath evaluates `path` in the scope of the container's basefs, with proper path
// sanitisation. Symlinks are all scoped to the basefs of the container, as
// though the container's basefs was `/`.
//
// The basefs of a container is the host-facing path which is bind-mounted as
// `/` inside the container. This method is essentially used to access a
// particular path inside the container as though you were a process in that
// container.
//
// NOTE: The returned path is *only* safely scoped inside the container's basefs
// if no component of the returned path changes (such as a component
// symlinking to a different path) between using this method and using the
// path. See symlink.FollowSymlinkInScope for more details.
func (container *Container) GetResourcePath(path string) (string, error) {
// IMPORTANT - These are paths on the OS where the daemon is running, hence
// any filepath operations must be done in an OS agnostic way.
cleanPath := filepath.Join(string(os.PathSeparator), path)
r, e := symlink.FollowSymlinkInScope(filepath.Join(container.basefs, cleanPath), container.basefs)
return r, e
}
// Evaluates `path` in the scope of the container's root, with proper path
// sanitisation. Symlinks are all scoped to the root of the container, as
// though the container's root was `/`.
//
// The root of a container is the host-facing configuration metadata directory.
// Only use this method to safely access the container's `container.json` or
// other metadata files. If in doubt, use container.GetResourcePath.
//
// NOTE: The returned path is *only* safely scoped inside the container's root
// if no component of the returned path changes (such as a component
// symlinking to a different path) between using this method and using the
// path. See symlink.FollowSymlinkInScope for more details.
func (container *Container) getRootResourcePath(path string) (string, error) {
// IMPORTANT - These are paths on the OS where the daemon is running, hence
// any filepath operations must be done in an OS agnostic way.
cleanPath := filepath.Join(string(os.PathSeparator), path)
return symlink.FollowSymlinkInScope(filepath.Join(container.root, cleanPath), container.root)
}
// streamConfig.StdinPipe returns a WriteCloser which can be used to feed data
// to the standard input of the container's active process.
// Container.StdoutPipe and Container.StderrPipe each return a ReadCloser
// which can be used to retrieve the standard output (and error) generated
// by the container's active process. The output (and error) are actually
// copied and delivered to all StdoutPipe and StderrPipe consumers, using
// a kind of "broadcaster".
func (streamConfig *streamConfig) StdinPipe() io.WriteCloser {
return streamConfig.stdinPipe
}
func (streamConfig *streamConfig) StdoutPipe() io.ReadCloser {
reader, writer := io.Pipe()
streamConfig.stdout.Add(writer)
return ioutils.NewBufReader(reader)
}
func (streamConfig *streamConfig) StderrPipe() io.ReadCloser {
reader, writer := io.Pipe()
streamConfig.stderr.Add(writer)
return ioutils.NewBufReader(reader)
}
// ExitOnNext signals to the monitor that it should not restart the container
// after we send the kill signal.
func (container *Container) ExitOnNext() {
container.monitor.ExitOnNext()
}
// Resize changes the TTY of the process running inside the container
// to the given height and width. The container must be running.
func (container *Container) Resize(h, w int) error {
if err := container.command.ProcessConfig.Terminal.Resize(h, w); err != nil {
return err
}
return nil
}
func (container *Container) hostConfigPath() (string, error) {
return container.getRootResourcePath("hostconfig.json")
}
func (container *Container) jsonPath() (string, error) {
return container.getRootResourcePath("config.json")
}
// This directory is only usable when the container is running
func (container *Container) rootfsPath() string {
return container.basefs
}
func validateID(id string) error {
if id == "" {
return derr.ErrorCodeEmptyID
}
return nil
}
// Returns true if the container exposes a certain port
func (container *Container) exposes(p nat.Port) bool {
_, exists := container.Config.ExposedPorts[p]
return exists
}
func (container *Container) getLogConfig(defaultConfig runconfig.LogConfig) runconfig.LogConfig {
cfg := container.hostConfig.LogConfig
if cfg.Type != "" || len(cfg.Config) > 0 { // container has log driver configured
if cfg.Type == "" {
cfg.Type = jsonfilelog.Name
}
return cfg
}
// Use daemon's default log config for containers
return defaultConfig
}
// StartLogger starts a new logger driver for the container.
func (container *Container) StartLogger(cfg runconfig.LogConfig) (logger.Logger, error) {
c, err := logger.GetLogDriver(cfg.Type)
if err != nil {
return nil, derr.ErrorCodeLoggingFactory.WithArgs(err)
}
ctx := logger.Context{
Config: cfg.Config,
ContainerID: container.ID,
ContainerName: container.Name,
ContainerEntrypoint: container.Path,
ContainerArgs: container.Args,
ContainerImageID: container.ImageID,
ContainerImageName: container.Config.Image,
ContainerCreated: container.Created,
ContainerEnv: container.Config.Env,
ContainerLabels: container.Config.Labels,
}
// Set logging file for "json-logger"
if cfg.Type == jsonfilelog.Name {
ctx.LogPath, err = container.getRootResourcePath(fmt.Sprintf("%s-json.log", container.ID))
if err != nil {
return nil, err
}
}
return c(ctx)
}
func (container *Container) getProcessLabel() string {
// even if we have a process label return "" if we are running
// in privileged mode
if container.hostConfig.Privileged {
return ""
}
return container.ProcessLabel
}
func (container *Container) getMountLabel() string {
if container.hostConfig.Privileged {
return ""
}
return container.MountLabel
}
func (container *Container) getExecIDs() []string {
return container.execCommands.List()
}
// Attach connects to the container's TTY, delegating to standard
// streams or websockets depending on the configuration.
func (container *Container) Attach(stdin io.ReadCloser, stdout io.Writer, stderr io.Writer) chan error {
return attach(&container.streamConfig, container.Config.OpenStdin, container.Config.StdinOnce, container.Config.Tty, stdin, stdout, stderr)
}
func attach(streamConfig *streamConfig, openStdin, stdinOnce, tty bool, stdin io.ReadCloser, stdout io.Writer, stderr io.Writer) chan error {
var (
cStdout, cStderr io.ReadCloser
cStdin io.WriteCloser
wg sync.WaitGroup
errors = make(chan error, 3)
)
if stdin != nil && openStdin {
cStdin = streamConfig.StdinPipe()
wg.Add(1)
}
if stdout != nil {
cStdout = streamConfig.StdoutPipe()
wg.Add(1)
}
if stderr != nil {
cStderr = streamConfig.StderrPipe()
wg.Add(1)
}
// Connect stdin of container to the http conn.
go func() {
if stdin == nil || !openStdin {
return
}
logrus.Debugf("attach: stdin: begin")
defer func() {
if stdinOnce && !tty {
cStdin.Close()
} else {
// No matter what, when stdin is closed (io.Copy unblock), close stdout and stderr
if cStdout != nil {
cStdout.Close()
}
if cStderr != nil {
cStderr.Close()
}
}
wg.Done()
logrus.Debugf("attach: stdin: end")
}()
var err error
if tty {
_, err = copyEscapable(cStdin, stdin)
} else {
_, err = io.Copy(cStdin, stdin)
}
if err == io.ErrClosedPipe {
err = nil
}
if err != nil {
logrus.Errorf("attach: stdin: %s", err)
errors <- err
return
}
}()
attachStream := func(name string, stream io.Writer, streamPipe io.ReadCloser) {
if stream == nil {
return
}
defer func() {
// Make sure stdin gets closed
if stdin != nil {
stdin.Close()
}
streamPipe.Close()
wg.Done()
logrus.Debugf("attach: %s: end", name)
}()
logrus.Debugf("attach: %s: begin", name)
_, err := io.Copy(stream, streamPipe)
if err == io.ErrClosedPipe {
err = nil
}
if err != nil {
logrus.Errorf("attach: %s: %v", name, err)
errors <- err
}
}
go attachStream("stdout", stdout, cStdout)
go attachStream("stderr", stderr, cStderr)
return promise.Go(func() error {
wg.Wait()
close(errors)
for err := range errors {
if err != nil {
return err
}
}
return nil
})
}
// Code c/c from io.Copy() modified to handle escape sequence
func copyEscapable(dst io.Writer, src io.ReadCloser) (written int64, err error) {
buf := make([]byte, 32*1024)
for {
nr, er := src.Read(buf)
if nr > 0 {
// ---- Docker addition
// char 16 is C-p
if nr == 1 && buf[0] == 16 {
nr, er = src.Read(buf)
// char 17 is C-q
if nr == 1 && buf[0] == 17 {
if err := src.Close(); err != nil {
return 0, err
}
return 0, nil
}
}
// ---- End of docker
nw, ew := dst.Write(buf[0:nr])
if nw > 0 {
written += int64(nw)
}
if ew != nil {
err = ew
break
}
if nr != nw {
err = io.ErrShortWrite
break
}
}
if er == io.EOF {
break
}
if er != nil {
err = er
break
}
}
return written, err
}
func (container *Container) shouldRestart() bool {
return container.hostConfig.RestartPolicy.Name == "always" ||
(container.hostConfig.RestartPolicy.Name == "unless-stopped" && !container.HasBeenManuallyStopped) ||
(container.hostConfig.RestartPolicy.Name == "on-failure" && container.ExitCode != 0)
}
func (daemon *Daemon) mountVolumes(container *Container) error {
mounts, err := daemon.setupMounts(container)
if err != nil {
return err
}
for _, m := range mounts {
dest, err := container.GetResourcePath(m.Destination)
if err != nil {
return err
}
var stat os.FileInfo
stat, err = os.Stat(m.Source)
if err != nil {
return err
}
if err = fileutils.CreateIfNotExists(dest, stat.IsDir()); err != nil {
return err
}
opts := "rbind,ro"
if m.Writable {
opts = "rbind,rw"
}
if err := mount.Mount(m.Source, dest, "bind", opts); err != nil {
return err
}
}
return nil
}
func (container *Container) unmountVolumes(forceSyscall bool) error {
var (
volumeMounts []volume.MountPoint
err error
)
for _, mntPoint := range container.MountPoints {
dest, err := container.GetResourcePath(mntPoint.Destination)
if err != nil {
return err
}
volumeMounts = append(volumeMounts, volume.MountPoint{Destination: dest, Volume: mntPoint.Volume})
}
// Append any network mounts to the list (this is a no-op on Windows)
if volumeMounts, err = appendNetworkMounts(container, volumeMounts); err != nil {
return err
}
for _, volumeMount := range volumeMounts {
if forceSyscall {
if err := system.Unmount(volumeMount.Destination); err != nil {
logrus.Warnf("%s unmountVolumes: Failed to force umount %v", container.ID, err)
}
}
if volumeMount.Volume != nil {
if err := volumeMount.Volume.Unmount(); err != nil {
return err
}
}
}
return nil
}
func (container *Container) addBindMountPoint(name, source, destination string, rw bool) {
container.MountPoints[destination] = &volume.MountPoint{
Name: name,
Source: source,
Destination: destination,
RW: rw,
}
}
func (container *Container) addLocalMountPoint(name, destination string, rw bool) {
container.MountPoints[destination] = &volume.MountPoint{
Name: name,
Driver: volume.DefaultDriverName,
Destination: destination,
RW: rw,
}
}
func (container *Container) addMountPointWithVolume(destination string, vol volume.Volume, rw bool) {
container.MountPoints[destination] = &volume.MountPoint{
Name: vol.Name(),
Driver: vol.DriverName(),
Destination: destination,
RW: rw,
Volume: vol,
}
}
func (container *Container) isDestinationMounted(destination string) bool {
return container.MountPoints[destination] != nil
}
func (container *Container) stopSignal() int {
var stopSignal syscall.Signal
if container.Config.StopSignal != "" {
stopSignal, _ = signal.ParseSignal(container.Config.StopSignal)
}
if int(stopSignal) == 0 {
stopSignal, _ = signal.ParseSignal(signal.DefaultStopSignal)
}
return int(stopSignal)
}