package daemon // import "github.com/docker/docker/daemon" import ( "fmt" "os" "path/filepath" "reflect" "strings" "time" "github.com/docker/docker/api/types" containertypes "github.com/docker/docker/api/types/container" "github.com/docker/docker/api/types/mount" mounttypes "github.com/docker/docker/api/types/mount" "github.com/docker/docker/container" "github.com/docker/docker/errdefs" "github.com/docker/docker/volume" "github.com/docker/docker/volume/drivers" "github.com/pkg/errors" "github.com/sirupsen/logrus" ) var ( // ErrVolumeReadonly is used to signal an error when trying to copy data into // a volume mount that is not writable. ErrVolumeReadonly = errors.New("mounted volume is marked read-only") ) type mounts []container.Mount // volumeToAPIType converts a volume.Volume to the type used by the Engine API func volumeToAPIType(v volume.Volume) *types.Volume { createdAt, _ := v.CreatedAt() tv := &types.Volume{ Name: v.Name(), Driver: v.DriverName(), CreatedAt: createdAt.Format(time.RFC3339), } if v, ok := v.(volume.DetailedVolume); ok { tv.Labels = v.Labels() tv.Options = v.Options() tv.Scope = v.Scope() } return tv } // Len returns the number of mounts. Used in sorting. func (m mounts) Len() int { return len(m) } // Less returns true if the number of parts (a/b/c would be 3 parts) in the // mount indexed by parameter 1 is less than that of the mount indexed by // parameter 2. Used in sorting. func (m mounts) Less(i, j int) bool { return m.parts(i) < m.parts(j) } // Swap swaps two items in an array of mounts. Used in sorting func (m mounts) Swap(i, j int) { m[i], m[j] = m[j], m[i] } // parts returns the number of parts in the destination of a mount. Used in sorting. func (m mounts) parts(i int) int { return strings.Count(filepath.Clean(m[i].Destination), string(os.PathSeparator)) } // registerMountPoints initializes the container mount points with the configured volumes and bind mounts. // It follows the next sequence to decide what to mount in each final destination: // // 1. Select the previously configured mount points for the containers, if any. // 2. Select the volumes mounted from another containers. Overrides previously configured mount point destination. // 3. Select the bind mounts set by the client. Overrides previously configured mount point destinations. // 4. Cleanup old volumes that are about to be reassigned. func (daemon *Daemon) registerMountPoints(container *container.Container, hostConfig *containertypes.HostConfig) (retErr error) { binds := map[string]bool{} mountPoints := map[string]*volume.MountPoint{} parser := volume.NewParser(container.OS) defer func() { // clean up the container mountpoints once return with error if retErr != nil { for _, m := range mountPoints { if m.Volume == nil { continue } daemon.volumes.Dereference(m.Volume, container.ID) } } }() dereferenceIfExists := func(destination string) { if v, ok := mountPoints[destination]; ok { logrus.Debugf("Duplicate mount point '%s'", destination) if v.Volume != nil { daemon.volumes.Dereference(v.Volume, container.ID) } } } // 1. Read already configured mount points. for destination, point := range container.MountPoints { mountPoints[destination] = point } // 2. Read volumes from other containers. for _, v := range hostConfig.VolumesFrom { containerID, mode, err := parser.ParseVolumesFrom(v) if err != nil { return err } c, err := daemon.GetContainer(containerID) if err != nil { return err } for _, m := range c.MountPoints { cp := &volume.MountPoint{ Type: m.Type, Name: m.Name, Source: m.Source, RW: m.RW && parser.ReadWrite(mode), Driver: m.Driver, Destination: m.Destination, Propagation: m.Propagation, Spec: m.Spec, CopyData: false, } if len(cp.Source) == 0 { v, err := daemon.volumes.GetWithRef(cp.Name, cp.Driver, container.ID) if err != nil { return err } cp.Volume = v } dereferenceIfExists(cp.Destination) mountPoints[cp.Destination] = cp } } // 3. Read bind mounts for _, b := range hostConfig.Binds { bind, err := parser.ParseMountRaw(b, hostConfig.VolumeDriver) if err != nil { return err } needsSlavePropagation, err := daemon.validateBindDaemonRoot(bind.Spec) if err != nil { return err } if needsSlavePropagation { bind.Propagation = mount.PropagationRSlave } // #10618 _, tmpfsExists := hostConfig.Tmpfs[bind.Destination] if binds[bind.Destination] || tmpfsExists { return duplicateMountPointError(bind.Destination) } if bind.Type == mounttypes.TypeVolume { // create the volume v, err := daemon.volumes.CreateWithRef(bind.Name, bind.Driver, container.ID, nil, nil) if err != nil { return err } bind.Volume = v bind.Source = v.Path() // bind.Name is an already existing volume, we need to use that here bind.Driver = v.DriverName() if bind.Driver == volume.DefaultDriverName { setBindModeIfNull(bind) } } binds[bind.Destination] = true dereferenceIfExists(bind.Destination) mountPoints[bind.Destination] = bind } for _, cfg := range hostConfig.Mounts { mp, err := parser.ParseMountSpec(cfg) if err != nil { return errdefs.InvalidParameter(err) } needsSlavePropagation, err := daemon.validateBindDaemonRoot(mp.Spec) if err != nil { return err } if needsSlavePropagation { mp.Propagation = mount.PropagationRSlave } if binds[mp.Destination] { return duplicateMountPointError(cfg.Target) } if mp.Type == mounttypes.TypeVolume { var v volume.Volume if cfg.VolumeOptions != nil { var driverOpts map[string]string if cfg.VolumeOptions.DriverConfig != nil { driverOpts = cfg.VolumeOptions.DriverConfig.Options } v, err = daemon.volumes.CreateWithRef(mp.Name, mp.Driver, container.ID, driverOpts, cfg.VolumeOptions.Labels) } else { v, err = daemon.volumes.CreateWithRef(mp.Name, mp.Driver, container.ID, nil, nil) } if err != nil { return err } mp.Volume = v mp.Name = v.Name() mp.Driver = v.DriverName() // only use the cached path here since getting the path is not necessary right now and calling `Path()` may be slow if cv, ok := v.(interface { CachedPath() string }); ok { mp.Source = cv.CachedPath() } if mp.Driver == volume.DefaultDriverName { setBindModeIfNull(mp) } } binds[mp.Destination] = true dereferenceIfExists(mp.Destination) mountPoints[mp.Destination] = mp } container.Lock() // 4. Cleanup old volumes that are about to be reassigned. for _, m := range mountPoints { if parser.IsBackwardCompatible(m) { if mp, exists := container.MountPoints[m.Destination]; exists && mp.Volume != nil { daemon.volumes.Dereference(mp.Volume, container.ID) } } } container.MountPoints = mountPoints container.Unlock() return nil } // lazyInitializeVolume initializes a mountpoint's volume if needed. // This happens after a daemon restart. func (daemon *Daemon) lazyInitializeVolume(containerID string, m *volume.MountPoint) error { if len(m.Driver) > 0 && m.Volume == nil { v, err := daemon.volumes.GetWithRef(m.Name, m.Driver, containerID) if err != nil { return err } m.Volume = v } return nil } // backportMountSpec resolves mount specs (introduced in 1.13) from pre-1.13 // mount configurations // The container lock should not be held when calling this function. // Changes are only made in-memory and may make changes to containers referenced // by `container.HostConfig.VolumesFrom` func (daemon *Daemon) backportMountSpec(container *container.Container) { container.Lock() defer container.Unlock() parser := volume.NewParser(container.OS) maybeUpdate := make(map[string]bool) for _, mp := range container.MountPoints { if mp.Spec.Source != "" && mp.Type != "" { continue } maybeUpdate[mp.Destination] = true } if len(maybeUpdate) == 0 { return } mountSpecs := make(map[string]bool, len(container.HostConfig.Mounts)) for _, m := range container.HostConfig.Mounts { mountSpecs[m.Target] = true } binds := make(map[string]*volume.MountPoint, len(container.HostConfig.Binds)) for _, rawSpec := range container.HostConfig.Binds { mp, err := parser.ParseMountRaw(rawSpec, container.HostConfig.VolumeDriver) if err != nil { logrus.WithError(err).Error("Got unexpected error while re-parsing raw volume spec during spec backport") continue } binds[mp.Destination] = mp } volumesFrom := make(map[string]volume.MountPoint) for _, fromSpec := range container.HostConfig.VolumesFrom { from, _, err := parser.ParseVolumesFrom(fromSpec) if err != nil { logrus.WithError(err).WithField("id", container.ID).Error("Error reading volumes-from spec during mount spec backport") continue } fromC, err := daemon.GetContainer(from) if err != nil { logrus.WithError(err).WithField("from-container", from).Error("Error looking up volumes-from container") continue } // make sure from container's specs have been backported daemon.backportMountSpec(fromC) fromC.Lock() for t, mp := range fromC.MountPoints { volumesFrom[t] = *mp } fromC.Unlock() } needsUpdate := func(containerMount, other *volume.MountPoint) bool { if containerMount.Type != other.Type || !reflect.DeepEqual(containerMount.Spec, other.Spec) { return true } return false } // main for _, cm := range container.MountPoints { if !maybeUpdate[cm.Destination] { continue } // nothing to backport if from hostconfig.Mounts if mountSpecs[cm.Destination] { continue } if mp, exists := binds[cm.Destination]; exists { if needsUpdate(cm, mp) { cm.Spec = mp.Spec cm.Type = mp.Type } continue } if cm.Name != "" { if mp, exists := volumesFrom[cm.Destination]; exists { if needsUpdate(cm, &mp) { cm.Spec = mp.Spec cm.Type = mp.Type } continue } if cm.Type != "" { // probably specified via the hostconfig.Mounts continue } // anon volume cm.Type = mounttypes.TypeVolume cm.Spec.Type = mounttypes.TypeVolume } else { if cm.Type != "" { // already updated continue } cm.Type = mounttypes.TypeBind cm.Spec.Type = mounttypes.TypeBind cm.Spec.Source = cm.Source if cm.Propagation != "" { cm.Spec.BindOptions = &mounttypes.BindOptions{ Propagation: cm.Propagation, } } } cm.Spec.Target = cm.Destination cm.Spec.ReadOnly = !cm.RW } } func (daemon *Daemon) traverseLocalVolumes(fn func(volume.Volume) error) error { localVolumeDriver, err := volumedrivers.GetDriver(volume.DefaultDriverName) if err != nil { return fmt.Errorf("can't retrieve local volume driver: %v", err) } vols, err := localVolumeDriver.List() if err != nil { return fmt.Errorf("can't retrieve local volumes: %v", err) } for _, v := range vols { name := v.Name() vol, err := daemon.volumes.Get(name) if err != nil { logrus.Warnf("failed to retrieve volume %s from store: %v", name, err) } else { // daemon.volumes.Get will return DetailedVolume v = vol } err = fn(v) if err != nil { return err } } return nil }