Documentation
¶
Index ¶
- Constants
- Variables
- func ChownPathByMaps(path string, toContainer, toHost *idtools.IDMappings) error
- func Mounted(fsType FsMagic, mountPath string) (bool, error)
- func MustRegister(name string, initFunc InitFunc)
- func NaiveCreateFromTemplate(d TemplateDriver, id, template string, templateIDMappings *idtools.IDMappings, ...) error
- func Register(name string, initFunc InitFunc) error
- type AdditionalLayer
- type AdditionalLayerStoreDriver
- type ApplyDiffOpts
- type Capabilities
- type CapabilityDriver
- type Checker
- type CreateOpts
- type DiffDriver
- type DiffGetterDriver
- type Differ
- type Driver
- type DriverWithDiffer
- type DriverWithDifferOutput
- type FileGetCloser
- type FsMagic
- type InitFunc
- type LayerIDMapUpdater
- type MountOpts
- type NaiveDiffDriver
- func (gdw *NaiveDiffDriver) ApplyDiff(id, parent string, options ApplyDiffOpts) (size int64, err error)
- func (gdw *NaiveDiffDriver) Changes(id string, idMappings *idtools.IDMappings, parent string, ...) (_ []archive.Change, retErr error)
- func (gdw *NaiveDiffDriver) Diff(id string, idMappings *idtools.IDMappings, parent string, ...) (arch io.ReadCloser, err error)
- func (gdw *NaiveDiffDriver) DiffSize(id string, idMappings *idtools.IDMappings, parent string, ...) (size int64, err error)
- type Options
- type ProtoDriver
- type RefCounter
- type TemplateDriver
Constants ¶
const ( // FsMagicAufs filesystem id for Aufs FsMagicAufs = FsMagic(0x61756673) // FsMagicBtrfs filesystem id for Btrfs FsMagicBtrfs = FsMagic(0x9123683E) // FsMagicCramfs filesystem id for Cramfs FsMagicCramfs = FsMagic(0x28cd3d45) // FsMagicEcryptfs filesystem id for eCryptfs FsMagicEcryptfs = FsMagic(0xf15f) // FsMagicExtfs filesystem id for Extfs FsMagicExtfs = FsMagic(0x0000EF53) // FsMagicF2fs filesystem id for F2fs FsMagicF2fs = FsMagic(0xF2F52010) // FsMagicGPFS filesystem id for GPFS FsMagicGPFS = FsMagic(0x47504653) // FsMagicJffs2Fs filesystem if for Jffs2Fs FsMagicJffs2Fs = FsMagic(0x000072b6) // FsMagicJfs filesystem id for Jfs FsMagicJfs = FsMagic(0x3153464a) // FsMagicNfsFs filesystem id for NfsFs FsMagicNfsFs = FsMagic(0x00006969) // FsMagicRAMFs filesystem id for RamFs FsMagicRAMFs = FsMagic(0x858458f6) // FsMagicReiserFs filesystem id for ReiserFs FsMagicReiserFs = FsMagic(0x52654973) // FsMagicSmbFs filesystem id for SmbFs FsMagicSmbFs = FsMagic(0x0000517B) // FsMagicSquashFs filesystem id for SquashFs FsMagicSquashFs = FsMagic(0x73717368) // FsMagicTmpFs filesystem id for TmpFs FsMagicTmpFs = FsMagic(0x01021994) // FsMagicVxFS filesystem id for VxFs FsMagicVxFS = FsMagic(0xa501fcf5) // FsMagicXfs filesystem id for Xfs FsMagicXfs = FsMagic(0x58465342) // FsMagicZfs filesystem id for Zfs FsMagicZfs = FsMagic(0x2fc12fc1) // FsMagicOverlay filesystem id for overlay FsMagicOverlay = FsMagic(0x794C7630) // FsMagicFUSE filesystem id for FUSE FsMagicFUSE = FsMagic(0x65735546) // FsMagicAcfs filesystem id for Acfs FsMagicAcfs = FsMagic(0x61636673) // FsMagicAfs filesystem id for Afs FsMagicAfs = FsMagic(0x5346414f) // FsMagicCephFs filesystem id for Ceph FsMagicCephFs = FsMagic(0x00C36400) // FsMagicCIFS filesystem id for CIFS FsMagicCIFS = FsMagic(0xFF534D42) // FsMagicFHGFS filesystem id for FHGFS FsMagicFHGFSFs = FsMagic(0x19830326) // FsMagicIBRIX filesystem id for IBRIX FsMagicIBRIX = FsMagic(0x013111A8) // FsMagicKAFS filesystem id for KAFS FsMagicKAFS = FsMagic(0x6B414653) // FsMagicLUSTRE filesystem id for LUSTRE FsMagicLUSTRE = FsMagic(0x0BD00BD0) // FsMagicNCP filesystem id for NCP FsMagicNCP = FsMagic(0x564C) // FsMagicNFSD filesystem id for NFSD FsMagicNFSD = FsMagic(0x6E667364) // FsMagicOCFS2 filesystem id for OCFS2 FsMagicOCFS2 = FsMagic(0x7461636F) // FsMagicPANFS filesystem id for PANFS FsMagicPANFS = FsMagic(0xAAD7AAEA) // FsMagicPRLFS filesystem id for PRLFS FsMagicPRLFS = FsMagic(0x7C7C6673) // FsMagicSMB2 filesystem id for SMB2 FsMagicSMB2 = FsMagic(0xFE534D42) // FsMagicSNFS filesystem id for SNFS FsMagicSNFS = FsMagic(0xBEEFDEAD) // FsMagicVBOXSF filesystem id for VBOXSF FsMagicVBOXSF = FsMagic(0x786F4256) // FsMagicVXFS filesystem id for VXFS FsMagicVXFS = FsMagic(0xA501FCF5) )
const ( // FsMagicUnsupported is a predefined constant value other than a valid filesystem id. FsMagicUnsupported = FsMagic(0x00000000) )
Variables ¶
var ( // ErrNotSupported returned when driver is not supported. ErrNotSupported = errors.New("driver not supported") // ErrPrerequisites returned when driver does not meet prerequisites. ErrPrerequisites = errors.New("prerequisites for driver not satisfied (wrong filesystem?)") // ErrIncompatibleFS returned when file system is not supported. ErrIncompatibleFS = errors.New("backing file system is unsupported for this graph driver") // ErrLayerUnknown returned when the specified layer is unknown by the driver. ErrLayerUnknown = errors.New("unknown layer") )
var ( // ApplyUncompressedLayer defines the unpack method used by the graph // driver. ApplyUncompressedLayer = chrootarchive.ApplyUncompressedLayer )
var ( // FsNames maps filesystem id to name of the filesystem. FsNames = map[FsMagic]string{ FsMagicAufs: "aufs", FsMagicBtrfs: "btrfs", FsMagicCramfs: "cramfs", FsMagicEcryptfs: "ecryptfs", FsMagicExtfs: "extfs", FsMagicF2fs: "f2fs", FsMagicGPFS: "gpfs", FsMagicJffs2Fs: "jffs2", FsMagicJfs: "jfs", FsMagicNfsFs: "nfs", FsMagicOverlay: "overlayfs", FsMagicRAMFs: "ramfs", FsMagicReiserFs: "reiserfs", FsMagicSmbFs: "smb", FsMagicSquashFs: "squashfs", FsMagicTmpFs: "tmpfs", FsMagicUnsupported: "unsupported", FsMagicVxFS: "vxfs", FsMagicXfs: "xfs", FsMagicZfs: "zfs", } )
Functions ¶
func ChownPathByMaps ¶
func ChownPathByMaps(path string, toContainer, toHost *idtools.IDMappings) error
ChownPathByMaps walks the filesystem tree, changing the ownership information using the toContainer and toHost mappings, using them to replace on-disk owner UIDs and GIDs which are "host" values in the first map with UIDs and GIDs for "host" values from the second map which correspond to the same "container" IDs.
func MustRegister ¶ added in v0.46.1
MustRegister registers an InitFunc for the driver, or panics. It is suitable for package’s init() sections.
func NaiveCreateFromTemplate ¶
func NaiveCreateFromTemplate(d TemplateDriver, id, template string, templateIDMappings *idtools.IDMappings, parent string, parentIDMappings *idtools.IDMappings, opts *CreateOpts, readWrite bool) error
CreateFromTemplate creates a layer with the same contents and parent as another layer. Internally, it may even depend on that other layer continuing to exist, as if it were actually a child of the child layer.
Types ¶
type AdditionalLayer ¶ added in v0.46.1
type AdditionalLayer interface { // CreateAs creates a new layer from this additional layer CreateAs(id, parent string) error // Info returns arbitrary information stored along with this layer (i.e. `info` file) Info() (io.ReadCloser, error) // Blob returns a reader of the raw contents of this layer. Blob() (io.ReadCloser, error) // Release tells the additional layer store that we don't use this handler. Release() }
AdditionalLayer reprents a layer that is stored in the additional layer store This API is experimental and can be changed without bumping the major version number.
type AdditionalLayerStoreDriver ¶ added in v0.46.1
type AdditionalLayerStoreDriver interface { Driver // LookupAdditionalLayer looks up additional layer store by the specified // digest and ref and returns an object representing that layer. LookupAdditionalLayer(d digest.Digest, ref string) (AdditionalLayer, error) // LookupAdditionalLayer looks up additional layer store by the specified // ID and returns an object representing that layer. LookupAdditionalLayerByID(id string) (AdditionalLayer, error) }
AdditionalLayerStoreDriver is the interface for driver that supports additional layer store functionality. This API is experimental and can be changed without bumping the major version number.
type ApplyDiffOpts ¶
type ApplyDiffOpts struct { Diff io.Reader Mappings *idtools.IDMappings MountLabel string IgnoreChownErrors bool ForceMask *os.FileMode }
ApplyDiffOpts contains optional arguments for ApplyDiff methods.
type Capabilities ¶
type Capabilities struct { // Flags that this driver is capable of reproducing exactly equivalent // diffs for read-only layers. If set, clients can rely on the driver // for consistent tar streams, and avoid extra processing to account // for potential differences (eg: the layer store's use of tar-split). ReproducesExactDiffs bool }
Capabilities defines a list of capabilities a driver may implement. These capabilities are not required; however, they do determine how a graphdriver can be used.
type CapabilityDriver ¶
type CapabilityDriver interface {
Capabilities() Capabilities
}
CapabilityDriver is the interface for layered file system drivers that can report on their Capabilities.
type Checker ¶
type Checker interface { // IsMounted returns true if the provided path is mounted for the specific checker IsMounted(path string) bool }
Checker makes checks on specified filesystems.
func NewDefaultChecker ¶
func NewDefaultChecker() Checker
NewDefaultChecker returns a check that parses /proc/mountinfo to check if the specified path is mounted.
func NewFsChecker ¶
NewFsChecker returns a checker configured for the provided FsMagic
type CreateOpts ¶
type CreateOpts struct { MountLabel string StorageOpt map[string]string *idtools.IDMappings // contains filtered or unexported fields }
CreateOpts contains optional arguments for Create() and CreateReadWrite() methods.
type DiffDriver ¶
type DiffDriver interface { // Diff produces an archive of the changes between the specified // layer and its parent layer which may be "". Diff(id string, idMappings *idtools.IDMappings, parent string, parentIDMappings *idtools.IDMappings, mountLabel string) (io.ReadCloser, error) // Changes produces a list of changes between the specified layer // and its parent layer. If parent is "", then all changes will be ADD changes. Changes(id string, idMappings *idtools.IDMappings, parent string, parentIDMappings *idtools.IDMappings, mountLabel string) ([]archive.Change, error) // ApplyDiff extracts the changeset from the given diff into the // layer with the specified id and parent, returning the size of the // new layer in bytes. // The io.Reader must be an uncompressed stream. ApplyDiff(id string, parent string, options ApplyDiffOpts) (size int64, err error) // DiffSize calculates the changes between the specified id // and its parent and returns the size in bytes of the changes // relative to its base filesystem directory. DiffSize(id string, idMappings *idtools.IDMappings, parent string, parentIDMappings *idtools.IDMappings, mountLabel string) (size int64, err error) }
DiffDriver is the interface to use to implement graph diffs
type DiffGetterDriver ¶
type DiffGetterDriver interface { Driver // DiffGetter returns an interface to efficiently retrieve the contents // of files in a layer. DiffGetter(id string) (FileGetCloser, error) }
DiffGetterDriver is the interface for layered file system drivers that provide a specialized function for getting file contents for tar-split.
type Differ ¶ added in v0.46.1
type Differ interface {
ApplyDiff(dest string, options *archive.TarOptions) (DriverWithDifferOutput, error)
}
Differ defines the interface for using a custom differ. This API is experimental and can be changed without bumping the major version number.
type Driver ¶
type Driver interface { ProtoDriver DiffDriver LayerIDMapUpdater }
Driver is the interface for layered/snapshot file system drivers.
func NewNaiveDiffDriver ¶
func NewNaiveDiffDriver(driver ProtoDriver, updater LayerIDMapUpdater) Driver
NewNaiveDiffDriver returns a fully functional driver that wraps the given ProtoDriver and adds the capability of the following methods which it may or may not support on its own:
Diff(id string, idMappings *idtools.IDMappings, parent string, parentMappings *idtools.IDMappings, mountLabel string) (io.ReadCloser, error) Changes(id string, idMappings *idtools.IDMappings, parent string, parentMappings *idtools.IDMappings, mountLabel string) ([]archive.Change, error) ApplyDiff(id, parent string, options ApplyDiffOpts) (size int64, err error) DiffSize(id string, idMappings *idtools.IDMappings, parent, parentMappings *idtools.IDMappings, mountLabel string) (size int64, err error)
type DriverWithDiffer ¶ added in v0.46.1
type DriverWithDiffer interface { Driver // ApplyDiffWithDiffer applies the changes using the callback function. // If id is empty, then a staging directory is created. The staging directory is guaranteed to be usable with ApplyDiffFromStagingDirectory. ApplyDiffWithDiffer(id, parent string, options *ApplyDiffOpts, differ Differ) (output DriverWithDifferOutput, err error) // ApplyDiffFromStagingDirectory applies the changes using the specified staging directory. ApplyDiffFromStagingDirectory(id, parent, stagingDirectory string, diffOutput *DriverWithDifferOutput, options *ApplyDiffOpts) error // CleanupStagingDirectory cleanups the staging directory. It can be used to cleanup the staging directory on errors CleanupStagingDirectory(stagingDirectory string) error // DifferTarget gets the location where files are stored for the layer. DifferTarget(id string) (string, error) }
DriverWithDiffer is the interface for direct diff access. This API is experimental and can be changed without bumping the major version number.
type DriverWithDifferOutput ¶ added in v0.46.1
type DriverWithDifferOutput struct { Differ Differ Target string Size int64 UIDs []uint32 GIDs []uint32 UncompressedDigest digest.Digest Metadata string BigData map[string][]byte }
DriverWithDifferOutput is the result of ApplyDiffWithDiffer This API is experimental and can be changed without bumping the major version number.
type FileGetCloser ¶
type FileGetCloser interface { storage.FileGetter // Close cleans up any resources associated with the FileGetCloser. Close() error }
FileGetCloser extends the storage.FileGetter interface with a Close method for cleaning up.
type FsMagic ¶
type FsMagic uint32
FsMagic unsigned id of the filesystem in use.
func GetFSMagic ¶
GetFSMagic returns the filesystem id given the path.
type LayerIDMapUpdater ¶
type LayerIDMapUpdater interface { // UpdateLayerIDMap walks the layer's filesystem tree, changing the ownership // information using the toContainer and toHost mappings, using them to replace // on-disk owner UIDs and GIDs which are "host" values in the first map with // UIDs and GIDs for "host" values from the second map which correspond to the // same "container" IDs. This method should only be called after a layer is // first created and populated, and before it is mounted, as other changes made // relative to a parent layer, but before this method is called, may be discarded // by Diff(). UpdateLayerIDMap(id string, toContainer, toHost *idtools.IDMappings, mountLabel string) error // SupportsShifting tells whether the driver support shifting of the UIDs/GIDs in a // image and it is not required to Chown the files when running in an user namespace. SupportsShifting() bool }
LayerIDMapUpdater is the interface that implements ID map changes for layers.
func NewNaiveLayerIDMapUpdater ¶
func NewNaiveLayerIDMapUpdater(driver ProtoDriver) LayerIDMapUpdater
NewNaiveLayerIDMapUpdater wraps the ProtoDriver in a LayerIDMapUpdater that uses ChownPathByMaps to update the ownerships in a layer's filesystem tree.
type MountOpts ¶
type MountOpts struct { // Mount label is the MAC Labels to assign to mount point (SELINUX) MountLabel string // UidMaps & GidMaps are the User Namespace mappings to be assigned to content in the mount point UidMaps []idtools.IDMap //nolint: golint,revive GidMaps []idtools.IDMap //nolint: golint Options []string // Volatile specifies whether the container storage can be optimized // at the cost of not syncing all the dirty files in memory. Volatile bool // DisableShifting forces the driver to not do any ID shifting at runtime. DisableShifting bool }
MountOpts contains optional arguments for Driver.Get() methods.
type NaiveDiffDriver ¶
type NaiveDiffDriver struct { ProtoDriver LayerIDMapUpdater }
NaiveDiffDriver takes a ProtoDriver and adds the capability of the Diffing methods which it may or may not support on its own. See the comment on the exported NewNaiveDiffDriver function below. Notably, the AUFS driver doesn't need to be wrapped like this.
func (*NaiveDiffDriver) ApplyDiff ¶
func (gdw *NaiveDiffDriver) ApplyDiff(id, parent string, options ApplyDiffOpts) (size int64, err error)
ApplyDiff extracts the changeset from the given diff into the layer with the specified id and parent, returning the size of the new layer in bytes.
func (*NaiveDiffDriver) Changes ¶
func (gdw *NaiveDiffDriver) Changes(id string, idMappings *idtools.IDMappings, parent string, parentMappings *idtools.IDMappings, mountLabel string) (_ []archive.Change, retErr error)
Changes produces a list of changes between the specified layer and its parent layer. If parent is "", then all changes will be ADD changes.
func (*NaiveDiffDriver) Diff ¶
func (gdw *NaiveDiffDriver) Diff(id string, idMappings *idtools.IDMappings, parent string, parentMappings *idtools.IDMappings, mountLabel string) (arch io.ReadCloser, err error)
Diff produces an archive of the changes between the specified layer and its parent layer which may be "".
func (*NaiveDiffDriver) DiffSize ¶
func (gdw *NaiveDiffDriver) DiffSize(id string, idMappings *idtools.IDMappings, parent string, parentMappings *idtools.IDMappings, mountLabel string) (size int64, err error)
DiffSize calculates the changes between the specified layer and its parent and returns the size in bytes of the changes relative to its base filesystem directory.
type Options ¶
type Options struct { Root string RunRoot string DriverOptions []string UIDMaps []idtools.IDMap GIDMaps []idtools.IDMap ExperimentalEnabled bool }
Options is used to initialize a graphdriver
type ProtoDriver ¶
type ProtoDriver interface { // String returns a string representation of this driver. String() string // CreateReadWrite creates a new, empty filesystem layer that is ready // to be used as the storage for a container. Additional options can // be passed in opts. parent may be "" and opts may be nil. CreateReadWrite(id, parent string, opts *CreateOpts) error // Create creates a new, empty, filesystem layer with the // specified id and parent and options passed in opts. Parent // may be "" and opts may be nil. Create(id, parent string, opts *CreateOpts) error // CreateFromTemplate creates a new filesystem layer with the specified id // and parent, with contents identical to the specified template layer. CreateFromTemplate(id, template string, templateIDMappings *idtools.IDMappings, parent string, parentIDMappings *idtools.IDMappings, opts *CreateOpts, readWrite bool) error // Remove attempts to remove the filesystem layer with this id. Remove(id string) error // Get returns the mountpoint for the layered filesystem referred // to by this id. You can optionally specify a mountLabel or "". // Optionally it gets the mappings used to create the layer. // Returns the absolute path to the mounted layered filesystem. Get(id string, options MountOpts) (dir string, err error) // Put releases the system resources for the specified id, // e.g, unmounting layered filesystem. Put(id string) error // Exists returns whether a filesystem layer with the specified // ID exists on this driver. Exists(id string) bool // Status returns a set of key-value pairs which give low // level diagnostic status about this driver. Status() [][2]string // Returns a set of key-value pairs which give low level information // about the image/container driver is managing. Metadata(id string) (map[string]string, error) // ReadWriteDiskUsage returns the disk usage of the writable directory for the specified ID. ReadWriteDiskUsage(id string) (*directory.DiskUsage, error) // Cleanup performs necessary tasks to release resources // held by the driver, e.g., unmounting all layered filesystems // known to this driver. Cleanup() error // AdditionalImageStores returns additional image stores supported by the driver // This API is experimental and can be changed without bumping the major version number. AdditionalImageStores() []string }
ProtoDriver defines the basic capabilities of a driver. This interface exists solely to be a minimum set of methods for client code which choose not to implement the entire Driver interface and use the NaiveDiffDriver wrapper constructor.
Use of ProtoDriver directly by client code is not recommended.
type RefCounter ¶
type RefCounter struct {
// contains filtered or unexported fields
}
RefCounter is a generic counter for use by graphdriver Get/Put calls
func NewRefCounter ¶
func NewRefCounter(c Checker) *RefCounter
NewRefCounter returns a new RefCounter
func (*RefCounter) Decrement ¶
func (c *RefCounter) Decrement(path string) int
Decrement decreases the ref count for the given id and returns the current count
func (*RefCounter) Increment ¶
func (c *RefCounter) Increment(path string) int
Increment increases the ref count for the given id and returns the current count
type TemplateDriver ¶
type TemplateDriver interface { DiffDriver CreateReadWrite(id, parent string, opts *CreateOpts) error Create(id, parent string, opts *CreateOpts) error Remove(id string) error }
TemplateDriver is just barely enough of a driver that we can implement a naive version of CreateFromTemplate on top of it.