Struct Overlay 

pub struct Overlay {
    pub lower: Vec<PathBuf>,
    pub upper: PathBuf,
    pub work: PathBuf,
    pub merged: PathBuf,
    pub userxattr: bool,
}

The directories of one overlay mount: read-only lower layers (top first), and the container’s own upper, work and merged directories.

Overlay::prepare only creates directories; mounting is the caller’s (mount -t overlay overlay -o <mount_data> <merged>, or the equivalent mount(2)), since it needs privileges this crate does not assume. The mount data must fit one page (4096 bytes); with long store paths and many layers, mount from inside the store with relative lower paths.

Fields

lower: Vec<PathBuf>

upper: PathBuf

work: PathBuf

merged: PathBuf

userxattr: bool

Mount with userxattr (markers in user.overlay.*, user namespaces).

Implementations

impl Overlay

pub fn prepare(lower: Vec<PathBuf>, dir: &Path) -> Result<Self>

Create <dir>/{upper,work,merged} over lower (topmost first).

pub fn for_layers( layers: &[PathBuf], dir: &Path, xattr: OverlayXattr, ) -> Result<Self>

An overlay over image layers given bottom first (as crate::LayerStore::image_layers returns them), with the xattr namespace the layers were unpacked with.

pub fn stack(layers: &[PathBuf]) -> Vec<PathBuf>

The lowerdir order for image layers given bottom first: top first, and a layer that repeats only at its topmost place (overlayfs refuses a lower directory twice; the upper copy re-applies everything the lower one did).

pub fn create(&self) -> Result<()>

Create the upper, work and merged directories of an overlay laid out by the caller.

pub fn mount_data(&self) -> String

The overlayfs mount data, with \, , and : in paths escaped.

Trait Implementations

impl Clone for Overlay

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Overlay

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Eq for Overlay

impl PartialEq for Overlay

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for Overlay