containers/skopeo

Skopeo is a command-line tool for working with container images and the registries that store them. A container image is a packaged snapshot of an application and everything it needs to run, used by tools like Docker and Podman. Skopeo lets you manage these images without needing to download or run them first, and without requiring administrator (root) access or a background service running on your machine. The most common operation is inspecting a remote image before you commit to downloading it. Skopeo can fetch an image manifest from any registry, showing you details like available version tags, creation date, the operating system it targets, labels set by the maintainer, and the list of layers that make up the image. This is useful when you want to check what you are about to pull without using disk space first. Skopeo can copy container images between different storage locations: from one registry to another, from a registry to a local folder, from Docker format to OCI format, or between other combinations. This makes it practical for mirroring images into a private internal registry, moving images between cloud providers, or preparing images for environments that have no internet access (sometimes called air-gapped deployments). Other operations include deleting images from a registry, syncing an entire external repository to an internal one, and authenticating with private registries using credentials from skopeo login or from existing Docker or Podman login sessions. Skopeo works with standard Docker Hub, Quay.io, OpenShift, GCR, Artifactory, and any registry that implements the Docker Registry API v2. It also works with local image stores used by Podman, CRI-O, and Buildah. The project is written in Go and is licensed under Apache 2.0.