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Share logic to create-or-replace a container

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The existing logic to handle container ID conflicts when attempting to
create a plugin container is not nearly as robust as the implementation
in daemon for user containers. Extract and refine the logic from daemon
and use it in the plugin executor.

Signed-off-by: Cory Snider <csnider@mirantis.com>
This commit is contained in:
Cory Snider 2022-05-05 13:00:45 -04:00
parent 4bafaa00aa
commit 6a2f385aea
3 changed files with 67 additions and 66 deletions
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35
daemon/start.go
View file

@ -9,6 +9,7 @@ import (
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"
)
@ -178,17 +179,10 @@ func (daemon *Daemon) containerStart(container *container.Container, checkpoint
ctx := context.TODO()
ctr, err := daemon.containerd.NewContainer(ctx, container.ID, spec, shim, createOptions)
if err != nil {
if errdefs.IsConflict(err) {
logrus.WithError(err).WithField("container", container.ID).Error("Container not cleaned up from containerd from previous run")
daemon.cleanupStaleContainer(ctx, container.ID)
ctr, err = daemon.containerd.NewContainer(ctx, container.ID, spec, shim, createOptions)
}
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(ctx, checkpointDir,
@ -220,31 +214,6 @@ func (daemon *Daemon) containerStart(container *container.Container, checkpoint
return nil
}
func (daemon *Daemon) cleanupStaleContainer(ctx context.Context, id string) {
// best effort to clean up old container object
log := logrus.WithContext(ctx).WithField("container", id)
ctr, err := daemon.containerd.LoadContainer(ctx, id)
if err != nil {
// Log an error no matter the kind. A container existed with the
// ID, so a NotFound error would be an exceptional situation
// worth logging.
log.WithError(err).Error("Error loading stale containerd container object")
return
}
if tsk, err := ctr.Task(ctx); err != nil {
if !errdefs.IsNotFound(err) {
log.WithError(err).Error("Error loading stale containerd task object")
}
} else {
if err := tsk.ForceDelete(ctx); err != nil {
log.WithError(err).Error("Error cleaning up stale containerd task object")
}
}
if err := ctr.Delete(ctx); err != nil && !errdefs.IsNotFound(err) {
log.WithError(err).Error("Error cleaning up stale containerd container object")
}
}
// 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) {

62
libcontainerd/replace.go Normal file
View file

@ -0,0 +1,62 @@
package libcontainerd // import "github.com/docker/docker/libcontainerd"
import (
"context"
"github.com/containerd/containerd"
"github.com/opencontainers/runtime-spec/specs-go"
"github.com/pkg/errors"
"github.com/sirupsen/logrus"
"github.com/docker/docker/errdefs"
"github.com/docker/docker/libcontainerd/types"
)
// ReplaceContainer creates a new container, replacing any existing container
// with the same id if necessary.
func ReplaceContainer(ctx context.Context, client types.Client, id string, spec *specs.Spec, shim string, runtimeOptions interface{}, opts ...containerd.NewContainerOpts) (types.Container, error) {
newContainer := func() (types.Container, error) {
return client.NewContainer(ctx, id, spec, shim, runtimeOptions, opts...)
}
ctr, err := newContainer()
if err == nil || !errdefs.IsConflict(err) {
return ctr, err
}
log := logrus.WithContext(ctx).WithField("container", id)
log.Debug("A container already exists with the same ID. Attempting to clean up the old container.")
ctr, err = client.LoadContainer(ctx, id)
if err != nil {
if errdefs.IsNotFound(err) {
// Task failed successfully: the container no longer exists,
// despite us not doing anything. May as well try to create
// the container again. It might succeed.
return newContainer()
}
return nil, errors.Wrap(err, "could not load stale containerd container object")
}
tsk, err := ctr.Task(ctx)
if err != nil {
if errdefs.IsNotFound(err) {
goto deleteContainer
}
// There is no point in trying to delete the container if we
// cannot determine whether or not it has a task. The containerd
// client would just try to load the task itself, get the same
// error, and give up.
return nil, errors.Wrap(err, "could not load stale containerd task object")
}
if err := tsk.ForceDelete(ctx); err != nil {
if !errdefs.IsNotFound(err) {
return nil, errors.Wrap(err, "could not delete stale containerd task object")
}
// The task might have exited on its own. Proceed with
// attempting to delete the container.
}
deleteContainer:
if err := ctr.Delete(ctx); err != nil && !errdefs.IsNotFound(err) {
return nil, errors.Wrap(err, "could not delete stale containerd container object")
}
return newContainer()
}

34
plugin/executor/containerd/containerd.go
View file

@ -75,39 +75,9 @@ func (p c8dPlugin) deleteTaskAndContainer(ctx context.Context) {
func (e *Executor) Create(id string, spec specs.Spec, stdout, stderr io.WriteCloser) error {
ctx := context.Background()
log := logrus.WithField("plugin", id)
ctr, err := e.client.NewContainer(ctx, id, &spec, e.runtime.Shim.Binary, e.runtime.Shim.Opts)
ctr, err := libcontainerd.ReplaceContainer(ctx, e.client, id, &spec, e.runtime.Shim.Binary, e.runtime.Shim.Opts)
if err != nil {
ctr2, err2 := e.client.LoadContainer(ctx, id)
if err2 != nil {
if !errdefs.IsNotFound(err2) {
log.WithError(err2).Warn("Received an error while attempting to load containerd container for plugin")
}
} else {
status := containerd.Unknown
t, err2 := ctr2.Task(ctx)
if err2 != nil {
if !errdefs.IsNotFound(err2) {
log.WithError(err2).Warn("Received an error while attempting to load containerd task for plugin")
}
} else {
s, err2 := t.Status(ctx)
if err2 != nil {
log.WithError(err2).Warn("Received an error while attempting to read plugin status")
} else {
status = s.Status
}
}
if status != containerd.Running && status != containerd.Unknown {
if err2 := ctr2.Delete(ctx); err2 != nil && !errdefs.IsNotFound(err2) {
log.WithError(err2).Error("Error cleaning up containerd container")
}
ctr, err = e.client.NewContainer(ctx, id, &spec, e.runtime.Shim.Binary, e.runtime.Shim.Opts)
}
}
if err != nil {
return errors.Wrap(err, "error creating containerd container")
}
return errors.Wrap(err, "error creating containerd container for plugin")
}
p := c8dPlugin{log: log, ctr: ctr}