package plugin // import "github.com/docker/docker/plugin" import ( "context" "encoding/json" "io" "os" "path/filepath" "reflect" "regexp" "sort" "strings" "sync" "syscall" "github.com/containerd/containerd/content" "github.com/containerd/containerd/content/local" "github.com/docker/docker/api/types" "github.com/docker/docker/pkg/authorization" "github.com/docker/docker/pkg/containerfs" "github.com/docker/docker/pkg/ioutils" v2 "github.com/docker/docker/plugin/v2" "github.com/docker/docker/registry" "github.com/moby/pubsub" "github.com/opencontainers/go-digest" specs "github.com/opencontainers/runtime-spec/specs-go" "github.com/pkg/errors" "github.com/sirupsen/logrus" ) const configFileName = "config.json" const rootFSFileName = "rootfs" var validFullID = regexp.MustCompile(`^([a-f0-9]{64})$`) // Executor is the interface that the plugin manager uses to interact with for starting/stopping plugins type Executor interface { Create(id string, spec specs.Spec, stdout, stderr io.WriteCloser) error IsRunning(id string) (bool, error) Restore(id string, stdout, stderr io.WriteCloser) (alive bool, err error) Signal(id string, signal syscall.Signal) error } // EndpointResolver provides looking up registry endpoints for pulling. type EndpointResolver interface { LookupPullEndpoints(hostname string) (endpoints []registry.APIEndpoint, err error) } func (pm *Manager) restorePlugin(p *v2.Plugin, c *controller) error { if p.IsEnabled() { return pm.restore(p, c) } return nil } type eventLogger func(id, name, action string) // ManagerConfig defines configuration needed to start new manager. type ManagerConfig struct { Store *Store // remove RegistryService EndpointResolver LiveRestoreEnabled bool // TODO: remove LogPluginEvent eventLogger Root string ExecRoot string CreateExecutor ExecutorCreator AuthzMiddleware *authorization.Middleware } // ExecutorCreator is used in the manager config to pass in an `Executor` type ExecutorCreator func(*Manager) (Executor, error) // Manager controls the plugin subsystem. type Manager struct { config ManagerConfig mu sync.RWMutex // protects cMap muGC sync.RWMutex // protects blobstore deletions cMap map[*v2.Plugin]*controller blobStore content.Store publisher *pubsub.Publisher executor Executor } // controller represents the manager's control on a plugin. type controller struct { restart bool exitChan chan bool timeoutInSecs int } // NewManager returns a new plugin manager. func NewManager(config ManagerConfig) (*Manager, error) { manager := &Manager{ config: config, } for _, dirName := range []string{manager.config.Root, manager.config.ExecRoot, manager.tmpDir()} { if err := os.MkdirAll(dirName, 0700); err != nil { return nil, errors.Wrapf(err, "failed to mkdir %v", dirName) } } var err error manager.executor, err = config.CreateExecutor(manager) if err != nil { return nil, err } manager.blobStore, err = local.NewStore(filepath.Join(manager.config.Root, "storage")) if err != nil { return nil, errors.Wrap(err, "error creating plugin blob store") } manager.cMap = make(map[*v2.Plugin]*controller) if err := manager.reload(); err != nil { return nil, errors.Wrap(err, "failed to restore plugins") } manager.publisher = pubsub.NewPublisher(0, 0) return manager, nil } func (pm *Manager) tmpDir() string { return filepath.Join(pm.config.Root, "tmp") } // HandleExitEvent is called when the executor receives the exit event // In the future we may change this, but for now all we care about is the exit event. func (pm *Manager) HandleExitEvent(id string) error { p, err := pm.config.Store.GetV2Plugin(id) if err != nil { return err } if err := os.RemoveAll(filepath.Join(pm.config.ExecRoot, id)); err != nil { logrus.WithError(err).WithField("id", id).Error("Could not remove plugin bundle dir") } pm.mu.RLock() c := pm.cMap[p] if c.exitChan != nil { close(c.exitChan) c.exitChan = nil // ignore duplicate events (containerd issue #2299) } restart := c.restart pm.mu.RUnlock() if restart { pm.enable(p, c, true) } else if err := recursiveUnmount(filepath.Join(pm.config.Root, id)); err != nil { return errors.Wrap(err, "error cleaning up plugin mounts") } return nil } func handleLoadError(err error, id string) { if err == nil { return } logger := logrus.WithError(err).WithField("id", id) if errors.Is(err, os.ErrNotExist) { // Likely some error while removing on an older version of docker logger.Warn("missing plugin config, skipping: this may be caused due to a failed remove and requires manual cleanup.") return } logger.Error("error loading plugin, skipping") } func (pm *Manager) reload() error { // todo: restore dir, err := os.ReadDir(pm.config.Root) if err != nil { return errors.Wrapf(err, "failed to read %v", pm.config.Root) } plugins := make(map[string]*v2.Plugin) for _, v := range dir { if validFullID.MatchString(v.Name()) { p, err := pm.loadPlugin(v.Name()) if err != nil { handleLoadError(err, v.Name()) continue } plugins[p.GetID()] = p } else { if validFullID.MatchString(strings.TrimSuffix(v.Name(), "-removing")) { // There was likely some error while removing this plugin, let's try to remove again here if err := containerfs.EnsureRemoveAll(v.Name()); err != nil { logrus.WithError(err).WithField("id", v.Name()).Warn("error while attempting to clean up previously removed plugin") } } } } pm.config.Store.SetAll(plugins) var wg sync.WaitGroup wg.Add(len(plugins)) for _, p := range plugins { c := &controller{exitChan: make(chan bool)} pm.mu.Lock() pm.cMap[p] = c pm.mu.Unlock() go func(p *v2.Plugin) { defer wg.Done() if err := pm.restorePlugin(p, c); err != nil { logrus.WithError(err).WithField("id", p.GetID()).Error("Failed to restore plugin") return } if p.Rootfs != "" { p.Rootfs = filepath.Join(pm.config.Root, p.PluginObj.ID, "rootfs") } // We should only enable rootfs propagation for certain plugin types that need it. for _, typ := range p.PluginObj.Config.Interface.Types { if (typ.Capability == "volumedriver" || typ.Capability == "graphdriver" || typ.Capability == "csinode" || typ.Capability == "csicontroller") && typ.Prefix == "docker" && strings.HasPrefix(typ.Version, "1.") { if p.PluginObj.Config.PropagatedMount != "" { propRoot := filepath.Join(filepath.Dir(p.Rootfs), "propagated-mount") // check if we need to migrate an older propagated mount from before // these mounts were stored outside the plugin rootfs if _, err := os.Stat(propRoot); os.IsNotExist(err) { rootfsProp := filepath.Join(p.Rootfs, p.PluginObj.Config.PropagatedMount) if _, err := os.Stat(rootfsProp); err == nil { if err := os.Rename(rootfsProp, propRoot); err != nil { logrus.WithError(err).WithField("dir", propRoot).Error("error migrating propagated mount storage") } } } if err := os.MkdirAll(propRoot, 0755); err != nil { logrus.Errorf("failed to create PropagatedMount directory at %s: %v", propRoot, err) } } } } pm.save(p) requiresManualRestore := !pm.config.LiveRestoreEnabled && p.IsEnabled() if requiresManualRestore { // if liveRestore is not enabled, the plugin will be stopped now so we should enable it if err := pm.enable(p, c, true); err != nil { logrus.WithError(err).WithField("id", p.GetID()).Error("failed to enable plugin") } } }(p) } wg.Wait() return nil } // Get looks up the requested plugin in the store. func (pm *Manager) Get(idOrName string) (*v2.Plugin, error) { return pm.config.Store.GetV2Plugin(idOrName) } func (pm *Manager) loadPlugin(id string) (*v2.Plugin, error) { p := filepath.Join(pm.config.Root, id, configFileName) dt, err := os.ReadFile(p) if err != nil { return nil, errors.Wrapf(err, "error reading %v", p) } var plugin v2.Plugin if err := json.Unmarshal(dt, &plugin); err != nil { return nil, errors.Wrapf(err, "error decoding %v", p) } return &plugin, nil } func (pm *Manager) save(p *v2.Plugin) error { pluginJSON, err := json.Marshal(p) if err != nil { return errors.Wrap(err, "failed to marshal plugin json") } if err := ioutils.AtomicWriteFile(filepath.Join(pm.config.Root, p.GetID(), configFileName), pluginJSON, 0600); err != nil { return errors.Wrap(err, "failed to write atomically plugin json") } return nil } // GC cleans up unreferenced blobs. This is recommended to run in a goroutine func (pm *Manager) GC() { pm.muGC.Lock() defer pm.muGC.Unlock() used := make(map[digest.Digest]struct{}) for _, p := range pm.config.Store.GetAll() { used[p.Config] = struct{}{} for _, b := range p.Blobsums { used[b] = struct{}{} } } ctx := context.TODO() pm.blobStore.Walk(ctx, func(info content.Info) error { _, ok := used[info.Digest] if ok { return nil } return pm.blobStore.Delete(ctx, info.Digest) }) } type logHook struct{ id string } func (logHook) Levels() []logrus.Level { return logrus.AllLevels } func (l logHook) Fire(entry *logrus.Entry) error { entry.Data = logrus.Fields{"plugin": l.id} return nil } func makeLoggerStreams(id string) (stdout, stderr io.WriteCloser) { logger := logrus.New() logger.Hooks.Add(logHook{id}) return logger.WriterLevel(logrus.InfoLevel), logger.WriterLevel(logrus.ErrorLevel) } func validatePrivileges(requiredPrivileges, privileges types.PluginPrivileges) error { if !isEqual(requiredPrivileges, privileges, isEqualPrivilege) { return errors.New("incorrect privileges") } return nil } func isEqual(arrOne, arrOther types.PluginPrivileges, compare func(x, y types.PluginPrivilege) bool) bool { if len(arrOne) != len(arrOther) { return false } sort.Sort(arrOne) sort.Sort(arrOther) for i := 1; i < arrOne.Len(); i++ { if !compare(arrOne[i], arrOther[i]) { return false } } return true } func isEqualPrivilege(a, b types.PluginPrivilege) bool { if a.Name != b.Name { return false } return reflect.DeepEqual(a.Value, b.Value) }