graphdriver

Documentation

Index

• Constants
• Variables
• func Register(name string, initFunc InitFunc) error
• type Driver
  • func GetDriver(name, home string, options []string, uidMaps, gidMaps []idtools.IDMap) (Driver, error)
  • func New(root string, options []string, uidMaps, gidMaps []idtools.IDMap) (driver Driver, err error)
• type FsMagic
  • func GetFSMagic(rootpath string) (FsMagic, error)
• type ImageRestorer
• type InitFunc
• type ProtoDriver
• type Recorder
• type Tagger

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)
	// FsMagicExtfs filesystem id for Extfs
	FsMagicExtfs = FsMagic(0x0000EF53)
	// FsMagicF2fs filesystem id for F2fs
	FsMagicF2fs = FsMagic(0xF2F52010)
	// 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)
)

const (
	// FsMagicUnsupported is a predifined contant value other than a valid filesystem id.
	FsMagicUnsupported = FsMagic(0x00000000)
)

Variables

var (
	// DefaultDriver if a storage driver is not specified.
	DefaultDriver string

	// ErrNotSupported returned when driver is not supported.
	ErrNotSupported = errors.New("driver not supported")
	// ErrPrerequisites retuned 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 = fmt.Errorf("backing file system is unsupported for this graph driver")
)

var (

	// FsNames maps filesystem id to name of the filesystem.
	FsNames = map[FsMagic]string{
		FsMagicAufs:        "aufs",
		FsMagicBtrfs:       "btrfs",
		FsMagicCramfs:      "cramfs",
		FsMagicExtfs:       "extfs",
		FsMagicF2fs:        "f2fs",
		FsMagicJffs2Fs:     "jffs2",
		FsMagicJfs:         "jfs",
		FsMagicNfsFs:       "nfs",
		FsMagicRAMFs:       "ramfs",
		FsMagicReiserFs:    "reiserfs",
		FsMagicSmbFs:       "smb",
		FsMagicSquashFs:    "squashfs",
		FsMagicTmpFs:       "tmpfs",
		FsMagicUnsupported: "unsupported",
		FsMagicVxFS:        "vxfs",
		FsMagicXfs:         "xfs",
		FsMagicZfs:         "zfs",
	}
)

Functions

func Register

func Register(name string, initFunc InitFunc) error

Register registers a InitFunc for the driver.

Types

type Driver

type Driver interface {
	ProtoDriver
	// Diff produces an archive of the changes between the specified
	// layer and its parent layer which may be "".
	Diff(id, parent string) (archive.Archive, 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 archive.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)
}

Driver is the interface for layered/snapshot file system drivers.

func GetDriver

func GetDriver(name, home string, options []string, uidMaps, gidMaps []idtools.IDMap) (Driver, error)

GetDriver initializes and returns the registered driver

func New

func New(root string, options []string, uidMaps, gidMaps []idtools.IDMap) (driver Driver, err error)

New creates the driver and initializes it at the specified root.

type FsMagic

type FsMagic uint32

FsMagic unsigned id of the filesystem in use.

func GetFSMagic

func GetFSMagic(rootpath string) (FsMagic, error)

GetFSMagic returns the filesystem id given the path.

type ImageRestorer

type ImageRestorer interface {
	RestoreCustomImages(tagger Tagger, recorder Recorder) ([]string, error)
}

ImageRestorer interface allows the implementer to add a custom image to the graph and tagstore.

type InitFunc

type InitFunc func(root string, options []string, uidMaps, gidMaps []idtools.IDMap) (Driver, error)

InitFunc initializes the storage driver.

type ProtoDriver

type ProtoDriver interface {
	// String returns a string representation of this driver.
	String() string
	// Create creates a new, empty, filesystem layer with the
	// specified id and parent. Parent may be "".
	Create(id, parent string) 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) (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.
	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 Recorder

type Recorder interface {
	Exists(id string) bool
	Register(img image.Descriptor, layerData io.Reader) error
}

Recorder is an interface that exposes the Graph.Register and Graph.Exists functions without needing to import graph.

type Tagger

type Tagger interface {
	Tag(repoName, tag, imageName string, force bool) error
}

Tagger is an interface that exposes the TagStore.Tag function without needing to import graph.