skopeo - Man Page

• Inspect a remote image from a registry: skopeo inspect docker://registry_hostname/image:tag
• List available tags for a remote image: skopeo list-tags docker://registry_hostname/image
• Download an image from a registry: skopeo copy docker://registry_hostname/image:tag dir:path/to/directory
• Copy an image from one registry to another: skopeo copy docker://source_registry/image:tag docker://destination_registry/image:tag
• Delete an image from a registry: skopeo delete docker://registry_hostname/image:tag
• Log in to a registry: skopeo login --username username registry_hostname

tldr.sh

skopeo [global options] command [command options]

skopeo is a command line utility providing various operations with container images and container image registries.

skopeo can copy container images between various containers image stores, converting them as necessary.  For example you can use skopeo to copy container images from one container registry to another.

skopeo can convert a Docker schema 2 or schema 1 container image to an OCI image.

skopeo can inspect a repository on a container registry without needlessly pulling the image. Pulling an image from a repository, especially a remote repository, is an expensive network and storage operation. Skopeo fetches the repository's manifest and displays a docker inspect-like json output about the repository or a tag. skopeo, in contrast to docker inspect, helps you gather useful information about a repository or a tag without requiring you to run docker pull - e.g. - Which tags are available for the given repository? Which labels does the image have?

skopeo can sign and verify container images.

skopeo can delete container images from a remote container registry.

Note: skopeo does not require any container runtimes to be running, to do most of its functionality.  It also does not require root, unless you are copying images into a container runtime storage backend, like the docker daemon or github.com/containers/storage.

Most commands refer to container images, using a transport:details format. The following formats are supported:

containers-storage:docker-reference
 An image located in a local containers/storage image store.  Both the location and image store are specified in /etc/containers/storage.conf. (Backend for Podman, CRI-O, Buildah and friends)

dir:path
 An existing local directory path storing the manifest, layer tarballs and signatures as individual files. This is a non-standardized format, primarily useful for debugging or noninvasive container inspection.

docker://docker-reference
 An image in a registry implementing the "Docker Registry HTTP API V2". By default, uses the authorization state in either $XDG_RUNTIME_DIR/containers/auth.json, which is set using (skopeo login). If the authorization state is not found there, $HOME/.docker/config.json is checked, which is set using (docker login).

docker-archive:path[:docker-reference]
 An image is stored in the docker save formatted file.  docker-reference is only used when creating such a file, and it must not contain a digest.

docker-daemon:docker-reference
 An image docker-reference stored in the docker daemon internal storage.  docker-reference must contain either a tag or a digest.  Alternatively, when reading images, the format can be docker-daemon:algo:digest (an image ID).

oci:path:tag
 An image tag in a directory compliant with "Open Container Image Layout Specification" at path.

oci-archive:path:tag
 An image tag in a tar archive compliant with "Open Container Image Layout Specification" at path.

See containers-transports(5) ⟨https://github.com/containers/image/blob/main/docs/containers-transports.5.md⟩ for details.

These options should be placed before the subcommand name. Individual subcommands have their own options.

--command-timeout duration

Timeout for the command execution.

--debug

enable debug output

--help,  -h

Show help

--insecure-policy

Adopt an insecure, permissive policy that allows anything. This obviates the need for a policy file.

--override-arch arch

Use arch instead of the architecture of the machine for choosing images.

--override-os os

Use OS instead of the running OS for choosing images.

--override-variant variant

Use variant instead of the running architecture variant for choosing images.

--policy path-to-policy

Path to a policy.json file to use for verifying signatures and deciding whether an image is trusted, overriding the default trust policy file.

--registries.d dir

Use registry configuration files in dir (e.g. for container signature storage), overriding the default path.

--tmpdir dir

Directory used to store temporary files. Defaults to /var/tmp.

--version,  -v

Print the version number

skopeo exits with status 0 on success, non-zero on error.

Details about the exit statuses:

1 Generic error, details can be found in the error message.

2 The input image cannot be found. Note that this is best effort and for remote registries the status often cannot be reliably reported.

/etc/containers/policy.json
 Default trust policy file, if --policy is not specified.
 The policy format is documented in containers-policy.json(5) ⟨https://github.com/containers/image/blob/main/docs/containers-policy.json.5.md⟩ .

/etc/containers/registries.d
 Default directory containing registry configuration, if --registries.d is not specified.
 The contents of this directory are documented in containers-registries.d(5) ⟨https://github.com/containers/image/blob/main/docs/containers-registries.d.5.md⟩.

skopeo-login(1), docker-login(1), containers-auth.json(5), containers-storage.conf(5), containers-policy.json(5), containers-transports(5)

Antonio Murdaca runcom@redhat.com ⟨mailto:runcom@redhat.com⟩, Miloslav Trmac mitr@redhat.com ⟨mailto:mitr@redhat.com⟩, Jhon Honce jhonce@redhat.com ⟨mailto:jhonce@redhat.com⟩

bootc-install-to-disk(8), bootc-install-to-existing-root(8), bootc-install-to-filesystem(8), containers-transports(5), skopeo-copy(1), skopeo-delete(1), skopeo-generate-sigstore-key(1), skopeo-inspect(1), skopeo-list-tags(1), skopeo-login(1), skopeo-logout(1), skopeo-manifest-digest(1), skopeo-standalone-sign(1), skopeo-standalone-verify(1), skopeo-sync(1), virt-bootstrap(1).