Crate microsandbox_image 

OCI image pulling, EROFS materialization, and caching for microsandbox.

This crate implements the OCI image lifecycle:

• Registry communication (pull, auth, platform resolution)
• Layer caching with content-addressable dedup
• Tar ingestion into in-memory file trees
• EROFS filesystem image generation (per-layer and flat modes)
• ext4 upper disk formatting for writable overlay upper layer
• Minimal EROFS reader for Append patches

Modules

erofs

ext4

snapshot

Snapshot artifact format.

tar

tree

Structs

CachedImageMetadata

Cached metadata for a pulled image reference.

CachedLayerMetadata

Cached metadata for a single layer descriptor.

Digest

OCI content-addressable digest (e.g., sha256:e3b0c44298fc1c14...).

GlobalCache

On-disk global cache for OCI layers and EROFS images.

ImageConfig

Runtime configuration parsed from an OCI image config blob.

ImageLoadOptions

Options for importing image archives.

ImageSaveConfig

Config fields used when synthesizing an exported Docker image config.

ImageSaveLayer

Layer data used when exporting an image.

ImageSaveRequest

Image data needed to export a Docker archive.

LoadedImage

One loaded image reference and its cached metadata.

Platform

Target platform for OCI image resolution.

PullOptions

Options for Registry::pull().

PullProgressHandle

Receiver for progress events.

PullProgressSender

Emits progress events. Uses try_send — never blocks downloads.

PullResult

Result of a successful image pull.

Reference

Reference provides a general type to represent any way of referencing images within an OCI registry.

Registry

OCI registry client with platform resolution, caching, and progress reporting.

RegistryBuilder

Builder for constructing a Registry client with optional auth and TLS settings.

Enums

ImageArchiveFormat

Archive format to use when saving images.

ImageError

Errors that can occur during image operations.

PullPolicy

Controls when the registry is contacted for manifest freshness.

PullProgress

Progress events emitted during image pull and EROFS materialization.

RegistryAuth

Authentication credentials for OCI registry access.

Functions

load_archive

Load a Docker image archive into the microsandbox image cache.

progress_channel

Create a progress channel pair.

save_archive

Save images as a container image archive.

save_docker_archive

Save images as a Docker-compatible image archive.

Type Aliases

Arch

Re-export of oci_spec::image::Arch.

ImageResult

Result type for image operations.

Os

Re-export of oci_spec::image::Os.