podman-container-tools/skopeo

Skopeo is a command-line utility written in Go that performs various operations on container images and image repositories without requiring root privileges or a running daemon. The tool works with both OCI images and Docker v2 images, and it can interact with API V2 container image registries such as Docker Hub and Quay.io, as well as private registries, local directories, and local OCI-layout directories.

The primary capabilities of skopeo include copying images between different storage mechanisms, inspecting remote images to view their properties and layers without pulling them locally, deleting images from repositories, syncing external image repositories to internal registries for air-gapped deployments, and handling authentication with appropriate credentials and certificates when required. The tool supports multiple image and repository types including containers-storage for local image stores used by Podman, CRI-O, and Buildah; dir paths for local directory storage; docker references for registry images; docker-archive for docker save-formatted files; docker-daemon for images in Docker's internal storage; and oci paths for OCI-compliant directories.

Skopeo's command suite includes skopeo-copy for transferring images between locations, skopeo-delete for marking images for deletion, skopeo-inspect for retrieving low-level image information, skopeo-list-tags for enumerating available tags, skopeo-login and skopeo-logout for registry authentication, skopeo-manifest-digest for computing manifest digests, skopeo-sync for synchronizing repositories, and debugging tools for signing and verifying image signatures.

The project holds Apache 2.0 licensing and maintains OpenSSF Best Practices certification, reflecting its commitment to security and quality standards in the container tooling space.