| package containerd // import "github.com/docker/docker/plugin/executor/containerd" |
| |
| import ( |
| "context" |
| "io" |
| "path/filepath" |
| "sync" |
| |
| "github.com/containerd/containerd/cio" |
| "github.com/containerd/containerd/linux/runctypes" |
| "github.com/docker/docker/errdefs" |
| "github.com/docker/docker/libcontainerd" |
| "github.com/opencontainers/runtime-spec/specs-go" |
| "github.com/pkg/errors" |
| "github.com/sirupsen/logrus" |
| ) |
| |
| // PluginNamespace is the name used for the plugins namespace |
| var PluginNamespace = "plugins.moby" |
| |
| // ExitHandler represents an object that is called when the exit event is received from containerd |
| type ExitHandler interface { |
| HandleExitEvent(id string) error |
| } |
| |
| // New creates a new containerd plugin executor |
| func New(rootDir string, remote libcontainerd.Remote, exitHandler ExitHandler) (*Executor, error) { |
| e := &Executor{ |
| rootDir: rootDir, |
| exitHandler: exitHandler, |
| } |
| client, err := remote.NewClient(PluginNamespace, e) |
| if err != nil { |
| return nil, errors.Wrap(err, "error creating containerd exec client") |
| } |
| e.client = client |
| return e, nil |
| } |
| |
| // Executor is the containerd client implementation of a plugin executor |
| type Executor struct { |
| rootDir string |
| client libcontainerd.Client |
| exitHandler ExitHandler |
| } |
| |
| // Create creates a new container |
| func (e *Executor) Create(id string, spec specs.Spec, stdout, stderr io.WriteCloser) error { |
| opts := runctypes.RuncOptions{ |
| RuntimeRoot: filepath.Join(e.rootDir, "runtime-root"), |
| } |
| ctx := context.Background() |
| err := e.client.Create(ctx, id, &spec, &opts) |
| if err != nil { |
| return err |
| } |
| |
| _, err = e.client.Start(ctx, id, "", false, attachStreamsFunc(stdout, stderr)) |
| return err |
| } |
| |
| // Restore restores a container |
| func (e *Executor) Restore(id string, stdout, stderr io.WriteCloser) error { |
| alive, _, err := e.client.Restore(context.Background(), id, attachStreamsFunc(stdout, stderr)) |
| if err != nil && !errdefs.IsNotFound(err) { |
| return err |
| } |
| if !alive { |
| _, _, err = e.client.DeleteTask(context.Background(), id) |
| if err != nil && !errdefs.IsNotFound(err) { |
| logrus.WithError(err).Errorf("failed to delete container plugin %s task from containerd", id) |
| return err |
| } |
| |
| err = e.client.Delete(context.Background(), id) |
| if err != nil && !errdefs.IsNotFound(err) { |
| logrus.WithError(err).Errorf("failed to delete container plugin %s from containerd", id) |
| return err |
| } |
| } |
| return nil |
| } |
| |
| // IsRunning returns if the container with the given id is running |
| func (e *Executor) IsRunning(id string) (bool, error) { |
| status, err := e.client.Status(context.Background(), id) |
| return status == libcontainerd.StatusRunning, err |
| } |
| |
| // Signal sends the specified signal to the container |
| func (e *Executor) Signal(id string, signal int) error { |
| return e.client.SignalProcess(context.Background(), id, libcontainerd.InitProcessName, signal) |
| } |
| |
| // ProcessEvent handles events from containerd |
| // All events are ignored except the exit event, which is sent of to the stored handler |
| func (e *Executor) ProcessEvent(id string, et libcontainerd.EventType, ei libcontainerd.EventInfo) error { |
| switch et { |
| case libcontainerd.EventExit: |
| // delete task and container |
| if _, _, err := e.client.DeleteTask(context.Background(), id); err != nil { |
| logrus.WithError(err).Errorf("failed to delete container plugin %s task from containerd", id) |
| } |
| |
| if err := e.client.Delete(context.Background(), id); err != nil { |
| logrus.WithError(err).Errorf("failed to delete container plugin %s from containerd", id) |
| } |
| return e.exitHandler.HandleExitEvent(ei.ContainerID) |
| } |
| return nil |
| } |
| |
| type rio struct { |
| cio.IO |
| |
| wg sync.WaitGroup |
| } |
| |
| func (c *rio) Wait() { |
| c.wg.Wait() |
| c.IO.Wait() |
| } |
| |
| func attachStreamsFunc(stdout, stderr io.WriteCloser) libcontainerd.StdioCallback { |
| return func(iop *cio.DirectIO) (cio.IO, error) { |
| if iop.Stdin != nil { |
| iop.Stdin.Close() |
| // closing stdin shouldn't be needed here, it should never be open |
| panic("plugin stdin shouldn't have been created!") |
| } |
| |
| rio := &rio{IO: iop} |
| rio.wg.Add(2) |
| go func() { |
| io.Copy(stdout, iop.Stdout) |
| stdout.Close() |
| rio.wg.Done() |
| }() |
| go func() { |
| io.Copy(stderr, iop.Stderr) |
| stderr.Close() |
| rio.wg.Done() |
| }() |
| return rio, nil |
| } |
| } |