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moby--moby/daemon/exec.go
Tonis Tiigi 37a3be2449 Move stdio attach from libcontainerd backend to callback
Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>
2016-10-24 00:20:36 -07:00

280 lines
7.8 KiB
Go

package daemon
import (
"fmt"
"io"
"strings"
"time"
"golang.org/x/net/context"
"github.com/Sirupsen/logrus"
"github.com/docker/docker/api/errors"
"github.com/docker/docker/api/types"
"github.com/docker/docker/api/types/strslice"
"github.com/docker/docker/container"
"github.com/docker/docker/daemon/exec"
"github.com/docker/docker/libcontainerd"
"github.com/docker/docker/pkg/pools"
"github.com/docker/docker/pkg/signal"
"github.com/docker/docker/pkg/term"
"github.com/docker/docker/utils"
)
// Seconds to wait after sending TERM before trying KILL
const termProcessTimeout = 10
func (d *Daemon) registerExecCommand(container *container.Container, config *exec.Config) {
// Storing execs in container in order to kill them gracefully whenever the container is stopped or removed.
container.ExecCommands.Add(config.ID, config)
// Storing execs in daemon for easy access via remote API.
d.execCommands.Add(config.ID, config)
}
// ExecExists looks up the exec instance and returns a bool if it exists or not.
// It will also return the error produced by `getConfig`
func (d *Daemon) ExecExists(name string) (bool, error) {
if _, err := d.getExecConfig(name); err != nil {
return false, err
}
return true, nil
}
// getExecConfig looks up the exec instance by name. If the container associated
// with the exec instance is stopped or paused, it will return an error.
func (d *Daemon) getExecConfig(name string) (*exec.Config, error) {
ec := d.execCommands.Get(name)
// If the exec is found but its container is not in the daemon's list of
// containers then it must have been deleted, in which case instead of
// saying the container isn't running, we should return a 404 so that
// the user sees the same error now that they will after the
// 5 minute clean-up loop is run which erases old/dead execs.
if ec != nil {
if container := d.containers.Get(ec.ContainerID); container != nil {
if !container.IsRunning() {
return nil, fmt.Errorf("Container %s is not running: %s", container.ID, container.State.String())
}
if container.IsPaused() {
return nil, errExecPaused(container.ID)
}
if container.IsRestarting() {
return nil, errContainerIsRestarting(container.ID)
}
return ec, nil
}
}
return nil, errExecNotFound(name)
}
func (d *Daemon) unregisterExecCommand(container *container.Container, execConfig *exec.Config) {
container.ExecCommands.Delete(execConfig.ID)
d.execCommands.Delete(execConfig.ID)
}
func (d *Daemon) getActiveContainer(name string) (*container.Container, error) {
container, err := d.GetContainer(name)
if err != nil {
return nil, err
}
if !container.IsRunning() {
return nil, errNotRunning{container.ID}
}
if container.IsPaused() {
return nil, errExecPaused(name)
}
if container.IsRestarting() {
return nil, errContainerIsRestarting(container.ID)
}
return container, nil
}
// ContainerExecCreate sets up an exec in a running container.
func (d *Daemon) ContainerExecCreate(name string, config *types.ExecConfig) (string, error) {
container, err := d.getActiveContainer(name)
if err != nil {
return "", err
}
cmd := strslice.StrSlice(config.Cmd)
entrypoint, args := d.getEntrypointAndArgs(strslice.StrSlice{}, cmd)
keys := []byte{}
if config.DetachKeys != "" {
keys, err = term.ToBytes(config.DetachKeys)
if err != nil {
err = fmt.Errorf("Invalid escape keys (%s) provided", config.DetachKeys)
return "", err
}
}
execConfig := exec.NewConfig()
execConfig.OpenStdin = config.AttachStdin
execConfig.OpenStdout = config.AttachStdout
execConfig.OpenStderr = config.AttachStderr
execConfig.ContainerID = container.ID
execConfig.DetachKeys = keys
execConfig.Entrypoint = entrypoint
execConfig.Args = args
execConfig.Tty = config.Tty
execConfig.Privileged = config.Privileged
execConfig.User = config.User
linkedEnv, err := d.setupLinkedContainers(container)
if err != nil {
return "", err
}
execConfig.Env = utils.ReplaceOrAppendEnvValues(container.CreateDaemonEnvironment(config.Tty, linkedEnv), config.Env)
if len(execConfig.User) == 0 {
execConfig.User = container.Config.User
}
d.registerExecCommand(container, execConfig)
d.LogContainerEvent(container, "exec_create: "+execConfig.Entrypoint+" "+strings.Join(execConfig.Args, " "))
return execConfig.ID, nil
}
// ContainerExecStart starts a previously set up exec instance. The
// std streams are set up.
// If ctx is cancelled, the process is terminated.
func (d *Daemon) ContainerExecStart(ctx context.Context, name string, stdin io.ReadCloser, stdout io.Writer, stderr io.Writer) (err error) {
var (
cStdin io.ReadCloser
cStdout, cStderr io.Writer
)
ec, err := d.getExecConfig(name)
if err != nil {
return errExecNotFound(name)
}
ec.Lock()
if ec.ExitCode != nil {
ec.Unlock()
err := fmt.Errorf("Error: Exec command %s has already run", ec.ID)
return errors.NewRequestConflictError(err)
}
if ec.Running {
ec.Unlock()
return fmt.Errorf("Error: Exec command %s is already running", ec.ID)
}
ec.Running = true
defer func() {
if err != nil {
ec.Running = false
exitCode := 126
ec.ExitCode = &exitCode
}
}()
ec.Unlock()
c := d.containers.Get(ec.ContainerID)
logrus.Debugf("starting exec command %s in container %s", ec.ID, c.ID)
d.LogContainerEvent(c, "exec_start: "+ec.Entrypoint+" "+strings.Join(ec.Args, " "))
if ec.OpenStdin && stdin != nil {
r, w := io.Pipe()
go func() {
defer w.Close()
defer logrus.Debug("Closing buffered stdin pipe")
pools.Copy(w, stdin)
}()
cStdin = r
}
if ec.OpenStdout {
cStdout = stdout
}
if ec.OpenStderr {
cStderr = stderr
}
if ec.OpenStdin {
ec.NewInputPipes()
} else {
ec.NewNopInputPipe()
}
p := libcontainerd.Process{
Args: append([]string{ec.Entrypoint}, ec.Args...),
Env: ec.Env,
Terminal: ec.Tty,
}
if err := execSetPlatformOpt(c, ec, &p); err != nil {
return err
}
attachErr := container.AttachStreams(ctx, ec.StreamConfig, ec.OpenStdin, true, ec.Tty, cStdin, cStdout, cStderr, ec.DetachKeys)
systemPid, err := d.containerd.AddProcess(ctx, c.ID, name, p, ec.InitializeStdio)
if err != nil {
return err
}
ec.Lock()
ec.Pid = systemPid
ec.Unlock()
select {
case <-ctx.Done():
logrus.Debugf("Sending TERM signal to process %v in container %v", name, c.ID)
d.containerd.SignalProcess(c.ID, name, int(signal.SignalMap["TERM"]))
select {
case <-time.After(termProcessTimeout * time.Second):
logrus.Infof("Container %v, process %v failed to exit within %d seconds of signal TERM - using the force", c.ID, name, termProcessTimeout)
d.containerd.SignalProcess(c.ID, name, int(signal.SignalMap["KILL"]))
case <-attachErr:
// TERM signal worked
}
return fmt.Errorf("context cancelled")
case err := <-attachErr:
if err != nil {
if _, ok := err.(container.DetachError); !ok {
return fmt.Errorf("exec attach failed with error: %v", err)
}
d.LogContainerEvent(c, "exec_detach")
}
}
return nil
}
// execCommandGC runs a ticker to clean up the daemon references
// of exec configs that are no longer part of the container.
func (d *Daemon) execCommandGC() {
for range time.Tick(5 * time.Minute) {
var (
cleaned int
liveExecCommands = d.containerExecIds()
)
for id, config := range d.execCommands.Commands() {
if config.CanRemove {
cleaned++
d.execCommands.Delete(id)
} else {
if _, exists := liveExecCommands[id]; !exists {
config.CanRemove = true
}
}
}
if cleaned > 0 {
logrus.Debugf("clean %d unused exec commands", cleaned)
}
}
}
// containerExecIds returns a list of all the current exec ids that are in use
// and running inside a container.
func (d *Daemon) containerExecIds() map[string]struct{} {
ids := map[string]struct{}{}
for _, c := range d.containers.List() {
for _, id := range c.ExecCommands.List() {
ids[id] = struct{}{}
}
}
return ids
}