overlay

Documentation

Index

• func CleanupContent(containerDir string) (Err error)
• func CleanupMount(contentDir string) (Err error)
• func GenerateStructure(containerDir, containerID, name string, rootUID, rootGID int) (string, error)
• func Mount(contentDir, source, dest string, rootUID, rootGID int, graphOptions []string) (mount specs.Mount, Err error)
• func MountReadOnly(contentDir, source, dest string, rootUID, rootGID int, graphOptions []string) (mount specs.Mount, Err error)
• func MountWithOptions(contentDir, source, dest string, opts *Options) (mount specs.Mount, Err error)
• func RemoveTemp(contentDir string) error
• func TempDir(containerDir string, rootUID, rootGID int) (string, error)
• func Unmount(contentDir string) error
• type Options

Functions

func CleanupContent

func CleanupContent(containerDir string) (Err error)

CleanupContent removes all temporary mountpoint and all content from directory

func CleanupMount

func CleanupMount(contentDir string) (Err error)

CleanupMount removes all temporary mountpoint content

func GenerateStructure

func GenerateStructure(containerDir, containerID, name string, rootUID, rootGID int) (string, error)

GenerateStructure generates an overlay directory structure for container content

func Mount

func Mount(contentDir, source, dest string, rootUID, rootGID int, graphOptions []string) (mount specs.Mount, Err error)

Mount creates a subdir of the contentDir based on the source directory from the source system. It then mounts up the source directory on to the generated mount point and returns the mount point to the caller.

func MountReadOnly

func MountReadOnly(contentDir, source, dest string, rootUID, rootGID int, graphOptions []string) (mount specs.Mount, Err error)

MountReadOnly creates a subdir of the contentDir based on the source directory from the source system. It then mounts up the source directory on to the generated mount point and returns the mount point to the caller. Note that no upper layer will be created rendering it a read-only mount

func MountWithOptions

func MountWithOptions(contentDir, source, dest string, opts *Options) (mount specs.Mount, Err error)

MountWithOptions creates a subdir of the contentDir based on the source directory from the source system. It then mounts up the source directory on to the generated mount point and returns the mount point to the caller. But allows api to set custom workdir, upperdir and other overlay options Following API is being used by podman at the moment

func RemoveTemp

func RemoveTemp(contentDir string) error

RemoveTemp removes temporary mountpoint and all content from its parent directory

func TempDir

func TempDir(containerDir string, rootUID, rootGID int) (string, error)

TempDir generates an overlay Temp directory in the container content

func Unmount

func Unmount(contentDir string) error

Unmount the overlay mountpoint

Types

type Options

type Options struct {
	// The Upper directory is normally writable layer in an overlay mount.
	// Note!! : Following API does not handles escaping or validates correctness of the values
	// passed to UpperDirOptionFragment instead API will try to pass values as is it
	// to the `mount` command. It is user's responsibility to make sure they pre-validate
	// these values. Invalid inputs may lead to undefined behaviour.
	// This is provided as-is, use it if it works for you, we can/will change/break that in the future.
	// See discussion here for more context: https://github.com/containers/buildah/pull/3715#discussion_r786036959
	// TODO: Should we address above comment and handle escaping of metacharacters like
	// `comma`, `backslash` ,`colon` and any other special characters
	UpperDirOptionFragment string
	// The Workdir is used to prepare files as they are switched between the layers.
	// Note!! : Following API does not handles escaping or validates correctness of the values
	// passed to WorkDirOptionFragment instead API will try to pass values as is it
	// to the `mount` command. It is user's responsibility to make sure they pre-validate
	// these values. Invalid inputs may lead to undefined behaviour.
	// This is provided as-is, use it if it works for you, we can/will change/break that in the future.
	// See discussion here for more context: https://github.com/containers/buildah/pull/3715#discussion_r786036959
	// TODO: Should we address above comment and handle escaping of metacharacters like
	// `comma`, `backslash` ,`colon` and any other special characters
	WorkDirOptionFragment string
	// Graph options relayed from podman, will be responsible for choosing mount program
	GraphOpts []string
	// Mark if following overlay is read only
	ReadOnly bool
	// RootUID is not used yet but keeping it here for legacy reasons.
	RootUID int
	// RootGID is not used yet but keeping it here for legacy reasons.
	RootGID int
}

Options type holds various configuration options for overlay MountWithOptions accepts following type so it is easier to specify more verbose configuration for overlay mount.