package images // import "github.com/docker/docker/daemon/images" import ( "context" "os" "runtime" "github.com/docker/docker/container" daemonevents "github.com/docker/docker/daemon/events" "github.com/docker/docker/distribution" "github.com/docker/docker/distribution/metadata" "github.com/docker/docker/distribution/xfer" "github.com/docker/docker/image" "github.com/docker/docker/layer" dockerreference "github.com/docker/docker/reference" "github.com/docker/docker/registry" "github.com/docker/libtrust" digest "github.com/opencontainers/go-digest" "github.com/pkg/errors" "github.com/sirupsen/logrus" ) type containerStore interface { // used by image delete First(container.StoreFilter) *container.Container // used by image prune, and image list List() []*container.Container // TODO: remove, only used for CommitBuildStep Get(string) *container.Container } // ImageServiceConfig is the configuration used to create a new ImageService type ImageServiceConfig struct { ContainerStore containerStore DistributionMetadataStore metadata.Store EventsService *daemonevents.Events ImageStore image.Store LayerStores map[string]layer.Store MaxConcurrentDownloads int MaxConcurrentUploads int MaxDownloadAttempts int ReferenceStore dockerreference.Store RegistryService registry.Service TrustKey libtrust.PrivateKey } // NewImageService returns a new ImageService from a configuration func NewImageService(config ImageServiceConfig) *ImageService { logrus.Debugf("Max Concurrent Downloads: %d", config.MaxConcurrentDownloads) logrus.Debugf("Max Concurrent Uploads: %d", config.MaxConcurrentUploads) logrus.Debugf("Max Download Attempts: %d", config.MaxDownloadAttempts) return &ImageService{ containers: config.ContainerStore, distributionMetadataStore: config.DistributionMetadataStore, downloadManager: xfer.NewLayerDownloadManager(config.LayerStores, config.MaxConcurrentDownloads, xfer.WithMaxDownloadAttempts(config.MaxDownloadAttempts)), eventsService: config.EventsService, imageStore: config.ImageStore, layerStores: config.LayerStores, referenceStore: config.ReferenceStore, registryService: config.RegistryService, trustKey: config.TrustKey, uploadManager: xfer.NewLayerUploadManager(config.MaxConcurrentUploads), } } // ImageService provides a backend for image management type ImageService struct { containers containerStore distributionMetadataStore metadata.Store downloadManager *xfer.LayerDownloadManager eventsService *daemonevents.Events imageStore image.Store layerStores map[string]layer.Store // By operating system pruneRunning int32 referenceStore dockerreference.Store registryService registry.Service trustKey libtrust.PrivateKey uploadManager *xfer.LayerUploadManager } // DistributionServices provides daemon image storage services type DistributionServices struct { DownloadManager distribution.RootFSDownloadManager V2MetadataService metadata.V2MetadataService LayerStore layer.Store // TODO: lcow ImageStore image.Store ReferenceStore dockerreference.Store } // DistributionServices return services controlling daemon image storage func (i *ImageService) DistributionServices() DistributionServices { return DistributionServices{ DownloadManager: i.downloadManager, V2MetadataService: metadata.NewV2MetadataService(i.distributionMetadataStore), LayerStore: i.layerStores[runtime.GOOS], ImageStore: i.imageStore, ReferenceStore: i.referenceStore, } } // CountImages returns the number of images stored by ImageService // called from info.go func (i *ImageService) CountImages() int { return i.imageStore.Len() } // Children returns the children image.IDs for a parent image. // called from list.go to filter containers // TODO: refactor to expose an ancestry for image.ID? func (i *ImageService) Children(id image.ID) []image.ID { return i.imageStore.Children(id) } // CreateLayer creates a filesystem layer for a container. // called from create.go // TODO: accept an opt struct instead of container? func (i *ImageService) CreateLayer(container *container.Container, initFunc layer.MountInit) (layer.RWLayer, error) { var layerID layer.ChainID if container.ImageID != "" { img, err := i.imageStore.Get(container.ImageID) if err != nil { return nil, err } layerID = img.RootFS.ChainID() } rwLayerOpts := &layer.CreateRWLayerOpts{ MountLabel: container.MountLabel, InitFunc: initFunc, StorageOpt: container.HostConfig.StorageOpt, } // Indexing by OS is safe here as validation of OS has already been performed in create() (the only // caller), and guaranteed non-nil return i.layerStores[container.OS].CreateRWLayer(container.ID, layerID, rwLayerOpts) } // GetLayerByID returns a layer by ID and operating system // called from daemon.go Daemon.restore(), and Daemon.containerExport() func (i *ImageService) GetLayerByID(cid string, os string) (layer.RWLayer, error) { return i.layerStores[os].GetRWLayer(cid) } // LayerStoreStatus returns the status for each layer store // called from info.go func (i *ImageService) LayerStoreStatus() map[string][][2]string { result := make(map[string][][2]string) for os, store := range i.layerStores { result[os] = store.DriverStatus() } return result } // GetLayerMountID returns the mount ID for a layer // called from daemon.go Daemon.Shutdown(), and Daemon.Cleanup() (cleanup is actually continerCleanup) // TODO: needs to be refactored to Unmount (see callers), or removed and replaced // with GetLayerByID func (i *ImageService) GetLayerMountID(cid string, os string) (string, error) { return i.layerStores[os].GetMountID(cid) } // Cleanup resources before the process is shutdown. // called from daemon.go Daemon.Shutdown() func (i *ImageService) Cleanup() { for os, ls := range i.layerStores { if ls != nil { if err := ls.Cleanup(); err != nil { logrus.Errorf("Error during layer Store.Cleanup(): %v %s", err, os) } } } } // GraphDriverForOS returns the name of the graph drvier // moved from Daemon.GraphDriverName, used by: // - newContainer // - to report an error in Daemon.Mount(container) func (i *ImageService) GraphDriverForOS(os string) string { return i.layerStores[os].DriverName() } // ReleaseLayer releases a layer allowing it to be removed // called from delete.go Daemon.cleanupContainer(), and Daemon.containerExport() func (i *ImageService) ReleaseLayer(rwlayer layer.RWLayer, containerOS string) error { metadata, err := i.layerStores[containerOS].ReleaseRWLayer(rwlayer) layer.LogReleaseMetadata(metadata) if err != nil && !errors.Is(err, layer.ErrMountDoesNotExist) && !errors.Is(err, os.ErrNotExist) { return errors.Wrapf(err, "driver %q failed to remove root filesystem", i.layerStores[containerOS].DriverName()) } return nil } // LayerDiskUsage returns the number of bytes used by layer stores // called from disk_usage.go func (i *ImageService) LayerDiskUsage(ctx context.Context) (int64, error) { var allLayersSize int64 layerRefs := i.getLayerRefs() for _, ls := range i.layerStores { allLayers := ls.Map() for _, l := range allLayers { select { case <-ctx.Done(): return allLayersSize, ctx.Err() default: size, err := l.DiffSize() if err == nil { if _, ok := layerRefs[l.ChainID()]; ok { allLayersSize += size } } else { logrus.Warnf("failed to get diff size for layer %v", l.ChainID()) } } } } return allLayersSize, nil } func (i *ImageService) getLayerRefs() map[layer.ChainID]int { tmpImages := i.imageStore.Map() layerRefs := map[layer.ChainID]int{} for id, img := range tmpImages { dgst := digest.Digest(id) if len(i.referenceStore.References(dgst)) == 0 && len(i.imageStore.Children(id)) != 0 { continue } rootFS := *img.RootFS rootFS.DiffIDs = nil for _, id := range img.RootFS.DiffIDs { rootFS.Append(id) chid := rootFS.ChainID() layerRefs[chid]++ } } return layerRefs } // UpdateConfig values // // called from reload.go func (i *ImageService) UpdateConfig(maxDownloads, maxUploads *int) { if i.downloadManager != nil && maxDownloads != nil { i.downloadManager.SetConcurrency(*maxDownloads) } if i.uploadManager != nil && maxUploads != nil { i.uploadManager.SetConcurrency(*maxUploads) } }