Documentation ¶
Index ¶
- Constants
- Variables
- func IsDriverNotSupported(err error) bool
- func Mounted(fsType FsMagic, mountPath string) (bool, error)
- func Register(name string, initFunc InitFunc) error
- type Capabilities
- type CapabilityDriver
- type Checker
- type CreateOpts
- type DiffDriver
- type DiffGetterDriver
- type Driver
- type ErrUnSupported
- type FileGetCloser
- type FsMagic
- type InitFunc
- type NaiveDiffDriver
- func (gdw *NaiveDiffDriver) ApplyDiff(id, parent string, diff io.Reader) (size int64, err error)
- func (gdw *NaiveDiffDriver) Changes(id, parent string) ([]archive.Change, error)
- func (gdw *NaiveDiffDriver) Diff(id, parent string) (arch io.ReadCloser, err error)
- func (gdw *NaiveDiffDriver) DiffSize(id, parent string) (size int64, err error)
- type NotSupportedError
- type Options
- type ProtoDriver
- type RefCounter
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) )
const ( // FsMagicUnsupported is a predefined constant value other than a valid filesystem id. FsMagicUnsupported = FsMagic(0x00000000) )
Variables ¶
var ApplyUncompressedLayer = chrootarchive.ApplyUncompressedLayer
ApplyUncompressedLayer defines the unpack method used by the graph driver.
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", FsMagicFUSE: "fuse", 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 IsDriverNotSupported ¶
IsDriverNotSupported returns true if the error initializing the graph driver is a non-supported error.
Types ¶
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 ¶ added in v1.13.1
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 ¶ added in v1.13.1
func NewDefaultChecker() Checker
NewDefaultChecker returns a check that parses /proc/mountinfo to check if the specified path is mounted.
func NewFsChecker ¶ added in v1.13.1
NewFsChecker returns a checker configured for the provided FsMagic
type CreateOpts ¶ added in v1.13.1
CreateOpts contains optional arguments for Create() and CreateReadWrite() methods.
type DiffDriver ¶ added in v1.13.1
type DiffDriver interface { // Diff produces an archive of the changes between the specified // layer and its parent layer which may be "". Diff(id, parent 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, parent 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 archive.Reader must be an uncompressed stream. ApplyDiff(id, parent string, diff io.Reader) (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, parent string) (size int64, err error) }
DiffDriver is the interface to use to implement graph diffs
type DiffGetterDriver ¶ added in v1.13.1
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 Driver ¶
type Driver interface { ProtoDriver DiffDriver }
Driver is the interface for layered/snapshot file system drivers.
func GetDriver ¶
func GetDriver(name string, pg plugingetter.PluginGetter, config Options) (Driver, error)
GetDriver initializes and returns the registered driver
func New ¶
func New(name string, pg plugingetter.PluginGetter, config Options) (Driver, error)
New creates the driver and initializes it at the specified root.
func NewNaiveDiffDriver ¶ added in v1.13.1
func NewNaiveDiffDriver(driver ProtoDriver, idMap idtools.IdentityMapping) 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, parent string) (archive.Archive, error) Changes(id, parent string) ([]archive.Change, error) ApplyDiff(id, parent string, diff archive.Reader) (size int64, err error) DiffSize(id, parent string) (size int64, err error)
type ErrUnSupported ¶
type ErrUnSupported interface {
NotSupported()
}
ErrUnSupported signals that the graph-driver is not supported on the current configuration
type FileGetCloser ¶ added in v1.13.1
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 NaiveDiffDriver ¶ added in v1.13.1
type NaiveDiffDriver struct { ProtoDriver IDMap idtools.IdentityMapping // If true, allow ApplyDiff to succeed in spite of failures to set // extended attributes on the unpacked files due to the destination // filesystem not supporting them or a lack of permissions. The // resulting unpacked layer may be subtly broken. BestEffortXattrs bool }
NaiveDiffDriver takes a ProtoDriver and adds the capability of the Diffing methods on the local file system, which it may or may not support on its own. See the comment on the exported NewNaiveDiffDriver function below.
func (*NaiveDiffDriver) ApplyDiff ¶ added in v1.13.1
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 ¶ added in v1.13.1
func (gdw *NaiveDiffDriver) Changes(id, parent string) ([]archive.Change, 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 ¶ added in v1.13.1
func (gdw *NaiveDiffDriver) Diff(id, parent string) (arch io.ReadCloser, err error)
Diff produces an archive of the changes between the specified layer and its parent layer which may be "".
type NotSupportedError ¶
type NotSupportedError string
NotSupportedError signals that the graph-driver is not supported on the current configuration
const ( // ErrNotSupported returned when driver is not supported. ErrNotSupported NotSupportedError = "driver not supported" // ErrPrerequisites returned when driver does not meet prerequisites. ErrPrerequisites NotSupportedError = "prerequisites for driver not satisfied (wrong filesystem?)" // ErrIncompatibleFS returned when file system is not supported. ErrIncompatibleFS NotSupportedError = "backing file system is unsupported for this graph driver" )
func (NotSupportedError) Error ¶
func (e NotSupportedError) Error() string
func (NotSupportedError) NotSupported ¶
func (e NotSupportedError) NotSupported()
NotSupported signals that a graph-driver is not supported.
type Options ¶ added in v1.13.1
type Options struct { Root string DriverOptions []string IDMap idtools.IdentityMapping 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 // 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 "". // Returns the absolute path to the mounted layered filesystem. Get(id, mountLabel string) (fs 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. GetMetadata(id string) (map[string]string, error) // Cleanup performs necessary tasks to release resources // held by the driver, e.g., unmounting all layered filesystems // known to this driver. Cleanup() error }
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 ¶ added in v1.13.1
type RefCounter struct {
// contains filtered or unexported fields
}
RefCounter is a generic counter for use by graphdriver Get/Put calls
func NewRefCounter ¶ added in v1.13.1
func NewRefCounter(c Checker) *RefCounter
NewRefCounter returns a new RefCounter
func (*RefCounter) Decrement ¶ added in v1.13.1
func (c *RefCounter) Decrement(path string) int
Decrement decreases the ref count for the given id and returns the current count
func (*RefCounter) Increment ¶ added in v1.13.1
func (c *RefCounter) Increment(path string) int
Increment increases the ref count for the given id and returns the current count