moby/daemon/start.go
Cory Snider 0141c6db81 daemon: don't checkpoint container until registered
(*Container).CheckpointTo() upserts a snapshot of the container to the
daemon's in-memory ViewDB and also persists the snapshot to disk. It
does not register the live container object with the daemon's container
store, however. The ViewDB and container store are used as the source of
truth for different operations, so having a container registered in one
but not the other can result in inconsistencies. In particular, the List
Containers API uses the ViewDB as its source of truth and the Container
Inspect API uses the container store.

The (*Daemon).setHostConfig() method is called fairly early in the
process of creating a container, long before the container is registered
in the daemon's container store. Due to a rogue CheckpointTo() call
inside setHostConfig(), there is a window of time where a container can
be included in a List Containers API response but "not exist" according
to the Container Inspect API and similar endpoints which operate on a
particular container. Remove the rogue call so that the caller has full
control over when the container is checkpointed and update callers to
checkpoint explicitly. No changes to (*Daemon).create() are needed as it
checkpoints the fully-created container via (*Daemon).Register().

Fixes #44512.

Signed-off-by: Cory Snider <csnider@mirantis.com>
2022-12-12 15:53:49 -05:00

259 lines
8.7 KiB
Go

package daemon // import "github.com/docker/docker/daemon"
import (
"context"
"runtime"
"time"
"github.com/docker/docker/api/types"
containertypes "github.com/docker/docker/api/types/container"
"github.com/docker/docker/container"
"github.com/docker/docker/errdefs"
"github.com/docker/docker/libcontainerd"
"github.com/pkg/errors"
"github.com/sirupsen/logrus"
)
// ContainerStart starts a container.
func (daemon *Daemon) ContainerStart(ctx context.Context, name string, hostConfig *containertypes.HostConfig, checkpoint string, checkpointDir string) error {
if checkpoint != "" && !daemon.HasExperimental() {
return errdefs.InvalidParameter(errors.New("checkpoint is only supported in experimental mode"))
}
ctr, err := daemon.GetContainer(name)
if err != nil {
return err
}
validateState := func() error {
ctr.Lock()
defer ctr.Unlock()
if ctr.Paused {
return errdefs.Conflict(errors.New("cannot start a paused container, try unpause instead"))
}
if ctr.Running {
return containerNotModifiedError{running: true}
}
if ctr.RemovalInProgress || ctr.Dead {
return errdefs.Conflict(errors.New("container is marked for removal and cannot be started"))
}
return nil
}
if err := validateState(); err != nil {
return err
}
// Windows does not have the backwards compatibility issue here.
if runtime.GOOS != "windows" {
// This is kept for backward compatibility - hostconfig should be passed when
// creating a container, not during start.
if hostConfig != nil {
logrus.Warn("DEPRECATED: Setting host configuration options when the container starts is deprecated and has been removed in Docker 1.12")
oldNetworkMode := ctr.HostConfig.NetworkMode
if err := daemon.setSecurityOptions(ctr, hostConfig); err != nil {
return errdefs.InvalidParameter(err)
}
if err := daemon.mergeAndVerifyLogConfig(&hostConfig.LogConfig); err != nil {
return errdefs.InvalidParameter(err)
}
if err := daemon.setHostConfig(ctr, hostConfig); err != nil {
return errdefs.InvalidParameter(err)
}
newNetworkMode := ctr.HostConfig.NetworkMode
if string(oldNetworkMode) != string(newNetworkMode) {
// if user has change the network mode on starting, clean up the
// old networks. It is a deprecated feature and has been removed in Docker 1.12
ctr.NetworkSettings.Networks = nil
}
if err := ctr.CheckpointTo(daemon.containersReplica); err != nil {
return errdefs.System(err)
}
ctr.InitDNSHostConfig()
}
} else {
if hostConfig != nil {
return errdefs.InvalidParameter(errors.New("Supplying a hostconfig on start is not supported. It should be supplied on create"))
}
}
// check if hostConfig is in line with the current system settings.
// It may happen cgroups are umounted or the like.
if _, err = daemon.verifyContainerSettings(ctr.HostConfig, nil, false); err != nil {
return errdefs.InvalidParameter(err)
}
// Adapt for old containers in case we have updates in this function and
// old containers never have chance to call the new function in create stage.
if hostConfig != nil {
if err := daemon.adaptContainerSettings(ctr.HostConfig, false); err != nil {
return errdefs.InvalidParameter(err)
}
}
return daemon.containerStart(ctx, ctr, checkpoint, checkpointDir, true)
}
// containerStart prepares the container to run by setting up everything the
// container needs, such as storage and networking, as well as links
// between containers. The container is left waiting for a signal to
// begin running.
func (daemon *Daemon) containerStart(ctx context.Context, container *container.Container, checkpoint string, checkpointDir string, resetRestartManager bool) (err error) {
start := time.Now()
container.Lock()
defer container.Unlock()
if resetRestartManager && container.Running { // skip this check if already in restarting step and resetRestartManager==false
return nil
}
if container.RemovalInProgress || container.Dead {
return errdefs.Conflict(errors.New("container is marked for removal and cannot be started"))
}
if checkpointDir != "" {
// TODO(mlaventure): how would we support that?
return errdefs.Forbidden(errors.New("custom checkpointdir is not supported"))
}
// if we encounter an error during start we need to ensure that any other
// setup has been cleaned up properly
defer func() {
if err != nil {
container.SetError(err)
// if no one else has set it, make sure we don't leave it at zero
if container.ExitCode() == 0 {
container.SetExitCode(128)
}
if err := container.CheckpointTo(daemon.containersReplica); err != nil {
logrus.Errorf("%s: failed saving state on start failure: %v", container.ID, err)
}
container.Reset(false)
daemon.Cleanup(container)
// if containers AutoRemove flag is set, remove it after clean up
if container.HostConfig.AutoRemove {
container.Unlock()
if err := daemon.ContainerRm(container.ID, &types.ContainerRmConfig{ForceRemove: true, RemoveVolume: true}); err != nil {
logrus.Errorf("can't remove container %s: %v", container.ID, err)
}
container.Lock()
}
}
}()
if err := daemon.conditionalMountOnStart(container); err != nil {
return err
}
if err := daemon.initializeNetworking(container); err != nil {
return err
}
spec, err := daemon.createSpec(ctx, container)
if err != nil {
return errdefs.System(err)
}
if resetRestartManager {
container.ResetRestartManager(true)
container.HasBeenManuallyStopped = false
}
if err := daemon.saveAppArmorConfig(container); err != nil {
return err
}
if checkpoint != "" {
checkpointDir, err = getCheckpointDir(checkpointDir, checkpoint, container.Name, container.ID, container.CheckpointDir(), false)
if err != nil {
return err
}
}
shim, createOptions, err := daemon.getLibcontainerdCreateOptions(container)
if err != nil {
return err
}
ctr, err := libcontainerd.ReplaceContainer(ctx, daemon.containerd, container.ID, spec, shim, createOptions)
if err != nil {
return translateContainerdStartErr(container.Path, container.SetExitCode, err)
}
// TODO(mlaventure): we need to specify checkpoint options here
tsk, err := ctr.Start(context.TODO(), // Passing ctx to ctr.Start caused integration tests to be stuck in the cleanup phase
checkpointDir, container.StreamConfig.Stdin() != nil || container.Config.Tty,
container.InitializeStdio)
if err != nil {
if err := ctr.Delete(context.Background()); err != nil {
logrus.WithError(err).WithField("container", container.ID).
Error("failed to delete failed start container")
}
return translateContainerdStartErr(container.Path, container.SetExitCode, err)
}
container.HasBeenManuallyRestarted = false
container.SetRunning(ctr, tsk, true)
container.HasBeenStartedBefore = true
daemon.setStateCounter(container)
daemon.initHealthMonitor(container)
if err := container.CheckpointTo(daemon.containersReplica); err != nil {
logrus.WithError(err).WithField("container", container.ID).
Errorf("failed to store container")
}
daemon.LogContainerEvent(container, "start")
containerActions.WithValues("start").UpdateSince(start)
return nil
}
// Cleanup releases any network resources allocated to the container along with any rules
// around how containers are linked together. It also unmounts the container's root filesystem.
func (daemon *Daemon) Cleanup(container *container.Container) {
// Microsoft HCS containers get in a bad state if host resources are
// released while the container still exists.
if ctr, ok := container.C8dContainer(); ok {
if err := ctr.Delete(context.Background()); err != nil {
logrus.Errorf("%s cleanup: failed to delete container from containerd: %v", container.ID, err)
}
}
daemon.releaseNetwork(container)
if err := container.UnmountIpcMount(); err != nil {
logrus.Warnf("%s cleanup: failed to unmount IPC: %s", container.ID, err)
}
if err := daemon.conditionalUnmountOnCleanup(container); err != nil {
// FIXME: remove once reference counting for graphdrivers has been refactored
// Ensure that all the mounts are gone
if mountid, err := daemon.imageService.GetLayerMountID(container.ID); err == nil {
daemon.cleanupMountsByID(mountid)
}
}
if err := container.UnmountSecrets(); err != nil {
logrus.Warnf("%s cleanup: failed to unmount secrets: %s", container.ID, err)
}
if err := recursiveUnmount(container.Root); err != nil {
logrus.WithError(err).WithField("container", container.ID).Warn("Error while cleaning up container resource mounts.")
}
for _, eConfig := range container.ExecCommands.Commands() {
daemon.unregisterExecCommand(container, eConfig)
}
if container.BaseFS != "" {
if err := container.UnmountVolumes(daemon.LogVolumeEvent); err != nil {
logrus.Warnf("%s cleanup: Failed to umount volumes: %v", container.ID, err)
}
}
container.CancelAttachContext()
}