volume

Documentation

Index

• Constants
• func ConvertTmpfsOptions(opt *mounttypes.TmpfsOptions, readOnly bool) (string, error)
• func GetPropagation(mode string) mounttypes.Propagation
• func HasPropagation(mode string) bool
• func IsVolumeNameValid(name string) (bool, error)
• func ParseVolumesFrom(spec string) (string, string, error)
• func ReadWrite(mode string) bool
• func ValidMountMode(mode string) bool
• func ValidateTmpfsMountDestination(dest string) error
• type Capability
• type DetailedVolume
• type Driver
• type MountPoint
  • func ParseMountRaw(raw, volumeDriver string) (*MountPoint, error)
  • func ParseMountSpec(cfg mounttypes.Mount, options ...func(*validateOpts)) (*MountPoint, error)
  • func (m *MountPoint) BackwardsCompatible() bool
  • func (m *MountPoint) HasResource(absolutePath string) bool
  • func (m *MountPoint) Path() string
  • func (m *MountPoint) Setup(mountLabel string, rootUID, rootGID int) (path string, err error)
• type Volume

Constants

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 (
	// DefaultCopyMode is the copy mode used by default for normal/named volumes
	DefaultCopyMode = true
)

const DefaultDriverName = "local"

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

const DefaultPropagationMode = mounttypes.PropagationRPrivate

DefaultPropagationMode defines what propagation mode should be used by default if user has not specified one explicitly. propagation modes

Functions

func ConvertTmpfsOptions

func ConvertTmpfsOptions(opt *mounttypes.TmpfsOptions, readOnly bool) (string, error)

ConvertTmpfsOptions converts *mounttypes.TmpfsOptions to the raw option string for mount(2).

func GetPropagation

func GetPropagation(mode string) mounttypes.Propagation

GetPropagation extracts and returns the mount propagation mode. If there are no specifications, then by default it is "private".

func HasPropagation

func HasPropagation(mode string) bool

HasPropagation checks if there is a valid propagation mode present in passed string. Returns true if a valid propagation mode specifier is present, false otherwise.

func IsVolumeNameValid

func IsVolumeNameValid(name string) (bool, error)

IsVolumeNameValid checks a volume name in a platform specific manner.

func ParseVolumesFrom

func ParseVolumesFrom(spec string) (string, string, error)

ParseVolumesFrom ensures that the supplied volumes-from is valid.

func ReadWrite

func ReadWrite(mode string) bool

ReadWrite tells you if a mode string is a valid read-write mode or not. If there are no specifications w.r.t read write mode, then by default it returns true.

func ValidMountMode

func ValidMountMode(mode string) bool

ValidMountMode will make sure the mount mode is valid. returns if it's a valid mount mode or not.

func ValidateTmpfsMountDestination

func ValidateTmpfsMountDestination(dest string) error

ValidateTmpfsMountDestination validates the destination of tmpfs mount. Currently, we have only two obvious rule for validation:

• path must not be "/"
• path must be absolute

We should add more rules carefully (#30166)

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
}

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 ParseMountRaw

func ParseMountRaw(raw, volumeDriver string) (*MountPoint, error)

ParseMountRaw parses a raw volume spec (e.g. `-v /foo:/bar:shared`) into a structured spec. Once the raw spec is parsed it relies on `ParseMountSpec` to validate the spec and create a MountPoint

func ParseMountSpec

func ParseMountSpec(cfg mounttypes.Mount, options ...func(*validateOpts)) (*MountPoint, error)

ParseMountSpec reads a mount config, validates it, and configures a mountpoint from it.

func (*MountPoint) BackwardsCompatible

func (m *MountPoint) BackwardsCompatible() bool

BackwardsCompatible decides whether this mount point can be used in old versions of Docker or not. Only bind mounts and local volumes can be used in old versions of Docker.

func (*MountPoint) HasResource

func (m *MountPoint) HasResource(absolutePath string) bool

HasResource checks whether the given absolute path for a container is in this mount point. If the relative path starts with `../` then the resource is outside of this mount point, but we can't simply check for this prefix because it misses `..` which is also outside of the mount, so check both.

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, rootUID, rootGID int) (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.

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
	// 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.