crane-export

Write tarball to stdout

$ crane export [image_name] -

$ crane export [image_name] [path/to/tarball]

$ crane export - [path/to/file]

crane export [OPTIONS] IMAGE TARFILE

-h, --help
    Display help for the export command

--platform PLATFORM
    Select platform to export (e.g., linux/amd64); defaults to primary platform or all for manifest lists

The crane export command is part of the crane CLI tool, designed for efficient manipulation of OCI (Open Container Initiative) container images without requiring a Docker daemon. It downloads a specified image from a container registry and exports it to a tar archive in a format compatible with docker load or podman load.

This is particularly useful for transferring images to air-gapped environments, creating backups, or migrating between registries. Crane handles authentication via standard Docker config files and supports multi-platform images by allowing platform selection. The export includes all image layers, config, and manifest data, preserving signatures if present (via cosign integration).

Unlike docker save, crane operates daemonlessly, making it lightweight and suitable for CI/CD pipelines or Kubernetes clusters. It fetches only necessary layers, optimizing bandwidth. For multi-arch images, specify a platform to export a single variant; otherwise, it defaults to the primary or all if it's a manifest list.

Installation is via go install or package managers. Usage requires registry access credentials if the image is private.

Requires network access to registry; outputs Docker-compatible tar (not pure OCI directory); large images consume significant disk space and time; no built-in compression (use gzip post-export if needed).
Authentication via ~/.docker/config.json; anonymous for public images.

crane export alpine:latest alpine.tar
crane export --platform linux/arm64 myregistry/image:v1 image-arm.tar
crane export ghcr.io/project/img:latest | gzip > img.tar.gz

go install github.com/google/go-containerregistry/cmd/crane@latest
Or via OS packages (e.g., brew install crane on macOS).

Developed by GoogleCloudPlatform as part of the sigstore ecosystem (~2020); evolved for daemonless image ops in supply-chain security; current in crane v0.20+ with multi-platform support.

docker-save(1), docker-load(1), skopeo(1), podman-save(1)