volume

Documentation

Index

• Constants
• Variables
• type Capability
• type DetailedVolume
• type Driver
• type MountPoint
  • func (m *MountPoint) Cleanup() error
  • func (m *MountPoint) Path() string
  • func (m *MountPoint) Setup(mountLabel string, rootIDs idtools.IDPair, checkFun func(m *MountPoint) error) (path string, err error)
• type Parser
  • func NewParser(containerOS string) Parser
• type Volume

Constants

const (
	// OSLinux is the same as runtime.GOOS on linux
	OSLinux = "linux"
	// OSWindows is the same as runtime.GOOS on windows
	OSWindows = "windows"
)

const (
	LocalScope  = "local"
	GlobalScope = "global"
)

Scopes define if a volume has is cluster-wide (global) or local only. Scopes are returned by the volume driver when it is queried for capabilities and then set on a volume

const DefaultDriverName = "local"

DefaultDriverName is the driver name used for the driver implemented in the local package.

Variables

var ErrVolumeTargetIsRoot = errors.New("invalid specification: destination can't be '/'")

ErrVolumeTargetIsRoot is returned when the target destination is root. It's used by both LCOW and Linux parsers.

Types

type Capability

type Capability struct {
	// Scope is the scope of the driver, `global` or `local`
	// A `global` scope indicates that the driver manages volumes across the cluster
	// A `local` scope indicates that the driver only manages volumes resources local to the host
	// Scope is declared by the driver
	Scope string
}

Capability defines a set of capabilities that a driver is able to handle.

type DetailedVolume

type DetailedVolume interface {
	Labels() map[string]string
	Options() map[string]string
	Scope() string
	Volume
}

DetailedVolume wraps a Volume with user-defined labels, options, and cluster scope (e.g., `local` or `global`)

type Driver

type Driver interface {
	// Name returns the name of the volume driver.
	Name() string
	// Create makes a new volume with the given name.
	Create(name string, opts map[string]string) (Volume, error)
	// Remove deletes the volume.
	Remove(vol Volume) (err error)
	// List lists all the volumes the driver has
	List() ([]Volume, error)
	// Get retrieves the volume with the requested name
	Get(name string) (Volume, error)
	// Scope returns the scope of the driver (e.g. `global` or `local`).
	// Scope determines how the driver is handled at a cluster level
	Scope() string
}

Driver is for creating and removing volumes.

type MountPoint

type MountPoint struct {
	// Source is the source path of the mount.
	// E.g. `mount --bind /foo /bar`, `/foo` is the `Source`.
	Source string
	// Destination is the path relative to the container root (`/`) to the mount point
	// It is where the `Source` is mounted to
	Destination string
	// RW is set to true when the mountpoint should be mounted as read-write
	RW bool
	// Name is the name reference to the underlying data defined by `Source`
	// e.g., the volume name
	Name string
	// Driver is the volume driver used to create the volume (if it is a volume)
	Driver string
	// Type of mount to use, see `Type<foo>` definitions in github.com/docker/docker/api/types/mount
	Type mounttypes.Type `json:",omitempty"`
	// Volume is the volume providing data to this mountpoint.
	// This is nil unless `Type` is set to `TypeVolume`
	Volume Volume `json:"-"`

	// Mode is the comma separated list of options supplied by the user when creating
	// the bind/volume mount.
	// Note Mode is not used on Windows
	Mode string `json:"Relabel,omitempty"` // Originally field was `Relabel`"

	// Propagation describes how the mounts are propagated from the host into the
	// mount point, and vice-versa.
	// See https://www.kernel.org/doc/Documentation/filesystems/sharedsubtree.txt
	// Note Propagation is not used on Windows
	Propagation mounttypes.Propagation `json:",omitempty"` // Mount propagation string

	// Specifies if data should be copied from the container before the first mount
	// Use a pointer here so we can tell if the user set this value explicitly
	// This allows us to error out when the user explicitly enabled copy but we can't copy due to the volume being populated
	CopyData bool `json:"-"`
	// ID is the opaque ID used to pass to the volume driver.
	// This should be set by calls to `Mount` and unset by calls to `Unmount`
	ID string `json:",omitempty"`

	// Sepc is a copy of the API request that created this mount.
	Spec mounttypes.Mount
	// contains filtered or unexported fields
}

MountPoint is the intersection point between a volume and a container. It specifies which volume is to be used and where inside a container it should be mounted.

func (*MountPoint) Cleanup

func (m *MountPoint) Cleanup() error

Cleanup frees resources used by the mountpoint

func (*MountPoint) Path

func (m *MountPoint) Path() string

Path returns the path of a volume in a mount point.

func (*MountPoint) Setup

func (m *MountPoint) Setup(mountLabel string, rootIDs idtools.IDPair, checkFun func(m *MountPoint) error) (path string, err error)

Setup sets up a mount point by either mounting the volume if it is configured, or creating the source directory if supplied. The, optional, checkFun parameter allows doing additional checking before creating the source directory on the host.

type Parser

type Parser interface {
	ParseMountRaw(raw, volumeDriver string) (*MountPoint, error)
	ParseMountSpec(cfg mount.Mount) (*MountPoint, error)
	ParseVolumesFrom(spec string) (string, string, error)
	DefaultPropagationMode() mount.Propagation
	ConvertTmpfsOptions(opt *mount.TmpfsOptions, readOnly bool) (string, error)
	DefaultCopyMode() bool
	ValidateVolumeName(name string) error
	ReadWrite(mode string) bool
	IsBackwardCompatible(m *MountPoint) bool
	HasResource(m *MountPoint, absPath string) bool
	ValidateTmpfsMountDestination(dest string) error
	ValidateMountConfig(mt *mount.Mount) error
}

Parser represents a platform specific parser for mount expressions

func NewParser

func NewParser(containerOS string) Parser

NewParser creates a parser for a given container OS, depending on the current host OS (linux on a windows host will resolve to an lcowParser)

type Volume

type Volume interface {
	// Name returns the name of the volume
	Name() string
	// DriverName returns the name of the driver which owns this volume.
	DriverName() string
	// Path returns the absolute path to the volume.
	Path() string
	// Mount mounts the volume and returns the absolute path to
	// where it can be consumed.
	Mount(id string) (string, error)
	// Unmount unmounts the volume when it is no longer in use.
	Unmount(id string) error
	// CreatedAt returns Volume Creation time
	CreatedAt() (time.Time, error)
	// Status returns low-level status information about a volume
	Status() map[string]interface{}
}

Volume is a place to store data. It is backed by a specific driver, and can be mounted.