package daemon // import "github.com/docker/docker/daemon" import ( "context" "time" containerpkg "github.com/docker/docker/container" "github.com/docker/docker/errdefs" "github.com/pkg/errors" "github.com/sirupsen/logrus" ) // ContainerStop looks for the given container and terminates it, // waiting the given number of seconds before forcefully killing the // container. If a negative number of seconds is given, ContainerStop // will wait for a graceful termination. An error is returned if the // container is not found, is already stopped, or if there is a // problem stopping the container. func (daemon *Daemon) ContainerStop(name string, seconds *int) error { container, err := daemon.GetContainer(name) if err != nil { return err } if !container.IsRunning() { return containerNotModifiedError{running: false} } if seconds == nil { stopTimeout := container.StopTimeout() seconds = &stopTimeout } if err := daemon.containerStop(container, *seconds); err != nil { return errdefs.System(errors.Wrapf(err, "cannot stop container: %s", name)) } return nil } // containerStop halts a container by sending a stop signal, waiting for the given // duration in seconds, and then calling SIGKILL and waiting for the // process to exit. If a negative duration is given, Stop will wait // for the initial signal forever. If the container is not running Stop returns // immediately. func (daemon *Daemon) containerStop(container *containerpkg.Container, seconds int) error { if !container.IsRunning() { return nil } stopSignal := container.StopSignal() // 1. Send a stop signal if err := daemon.killPossiblyDeadProcess(container, stopSignal); err != nil { // While normally we might "return err" here we're not going to // because if we can't stop the container by this point then // it's probably because it's already stopped. Meaning, between // the time of the IsRunning() call above and now it stopped. // Also, since the err return will be environment specific we can't // look for any particular (common) error that would indicate // that the process is already dead vs something else going wrong. // So, instead we'll give it up to 2 more seconds to complete and if // by that time the container is still running, then the error // we got is probably valid and so we force kill it. ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second) defer cancel() if status := <-container.Wait(ctx, containerpkg.WaitConditionNotRunning); status.Err() != nil { logrus.Infof("Container failed to stop after sending signal %d to the process, force killing", stopSignal) if err := daemon.killPossiblyDeadProcess(container, 9); err != nil { return err } } } // 2. Wait for the process to exit on its own ctx, cancel := context.WithTimeout(context.Background(), time.Duration(seconds)*time.Second) defer cancel() if status := <-container.Wait(ctx, containerpkg.WaitConditionNotRunning); status.Err() != nil { logrus.Infof("Container %v failed to exit within %d seconds of signal %d - using the force", container.ID, seconds, stopSignal) // 3. If it doesn't, then send SIGKILL if err := daemon.Kill(container); err != nil { // Wait without a timeout, ignore result. <-container.Wait(context.Background(), containerpkg.WaitConditionNotRunning) logrus.Warn(err) // Don't return error because we only care that container is stopped, not what function stopped it } } daemon.LogContainerEvent(container, "stop") return nil }