skopeo-copy.1.md

% skopeo-copy(1)

NAME

skopeo-copy - Copy an image (manifest, filesystem layers, signatures) from one location to another.

SYNOPSIS

skopeo copy [options] source-image destination-image

DESCRIPTION

Copy an image (manifest, filesystem layers, signatures) from one location to another.

Uses the system's trust policy to validate images, rejects images not trusted by the policy.

source-image use the "image name" format described above

destination-image use the "image name" format described above

source-image and destination-image are interpreted completely independently; e.g. the destination name does not automatically inherit any parts of the source name.

OPTIONS

--additional-tag=strings

Additional tags (supports docker-archive).

--all, -a

If source-image refers to a list of images, instead of copying just the image which matches the current OS and architecture (subject to the use of the global --override-os, --override-arch and --override-variant options), attempt to copy all of the images in the list, and the list itself.

--authfile path

Path of the authentication file. Default is ${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.

Note: You can also override the default path of the authentication file by setting the REGISTRY_AUTH_FILE environment variable. export REGISTRY_AUTH_FILE=path

--src-authfile path

Path of the authentication file for the source registry. Uses path given by --authfile, if not provided.

--dest-authfile path

Path of the authentication file for the destination registry. Uses path given by --authfile, if not provided.

--dest-shared-blob-dir directory

Directory to use to share blobs across OCI repositories.

--digestfile path

After copying the image, write the digest of the resulting image to the file.

--preserve-digests

Preserve the digests during copying. Fail if the digest cannot be preserved. Consider using --all at the same time.

--encrypt-layer ints

Experimental the 0-indexed layer indices, with support for negative indexing (e.g. 0 is the first layer, -1 is the last layer)

--format, -f manifest-type

MANIFEST TYPE (oci, v2s1, or v2s2) to use in the destination (default is manifest type of source, with fallbacks)

--help, -h

Print usage statement

--multi-arch option

Control what is copied if source-image refers to a multi-architecture image. Default is system.

Options:

• system: Copy only the image that matches the system architecture
• all: Copy the full multi-architecture image
• index-only: Copy only the index

The index-only option usually fails unless the referenced per-architecture images are already present in the destination, or the target registry supports sparse indexes.

--quiet, -q

Suppress output information when copying images.

--remove-signatures

Do not copy signatures, if any, from source-image. Necessary when copying a signed image to a destination which does not support signatures.

--sign-by key-id

Add a “simple signing” signature using that key ID for an image name corresponding to destination-image

--sign-by-sigstore param-file

Add a sigstore signature based on the options in the specified containers sigstore signing parameter file, param-file. See containers-sigstore-signing-params.yaml(5) for details about the file format.

--sign-by-sigstore-private-key path

Add a sigstore signature using a private key at path for an image name corresponding to destination-image

--sign-passphrase-file path

The passphare to use when signing with --sign-by or --sign-by-sigstore-private-key. Only the first line will be read. A passphrase stored in a file is of questionable security if other users can read this file. Do not use this option if at all avoidable.

--sign-identity reference

The identity to use when signing the image. The identity must be a fully specified docker reference. If the identity is not specified, the target docker reference will be used.

--src-shared-blob-dir directory

Directory to use to share blobs across OCI repositories.

--encryption-key protocol:keyfile

Specifies the encryption protocol, which can be JWE (RFC7516), PGP (RFC4880), and PKCS7 (RFC2315) and the key material required for image encryption. For instance, jwe:/path/to/key.pem or pgp:[email protected] or pkcs7:/path/to/x509-file.

--decryption-key key[:passphrase]

Key to be used for decryption of images. Key can point to keys and/or certificates. Decryption will be tried with all keys. If the key is protected by a passphrase, it is required to be passed in the argument and omitted otherwise.

--src-creds username[:password]

Credentials for accessing the source registry.

--dest-compress

Compress tarball image layers when saving to directory using the 'dir' transport. (default is same compression type as source).

--dest-decompress

Decompress tarball image layers when saving to directory using the 'dir' transport. (default is same compression type as source).

--dest-oci-accept-uncompressed-layers

Allow uncompressed image layers when saving to an OCI image using the 'oci' transport. (default is to compress things that aren't compressed).

--dest-creds username[:password]

Credentials for accessing the destination registry.

--src-cert-dir path

Use certificates at path (*.crt, *.cert, *.key) to connect to the source registry or daemon.

--src-no-creds

Access the registry anonymously.

--src-tls-verify=bool

Require HTTPS and verify certificates when talking to container source registry or daemon. Default to source registry setting.

--dest-cert-dir path

Use certificates at path (*.crt, *.cert, *.key) to connect to the destination registry or daemon.

--dest-no-creds

Access the registry anonymously.

--dest-tls-verify=bool

Require HTTPS and verify certificates when talking to container destination registry or daemon. Default to destination registry setting.

--src-daemon-host host

Copy from docker daemon at host. If host starts with tcp://, HTTPS is enabled by default. To use plain HTTP, use the form http:// (default is unix:///var/run/docker.sock).

--dest-daemon-host host

Copy to docker daemon at host. If host starts with tcp://, HTTPS is enabled by default. To use plain HTTP, use the form http:// (default is unix:///var/run/docker.sock).

Existing signatures, if any, are preserved as well.

--dest-compress-format format

Specifies the compression format to use. Supported values are: gzip and zstd.

--dest-compress-level format

Specifies the compression level to use. The value is specific to the compression algorithm used, e.g. for zstd the accepted values are in the range 1-20 (inclusive), while for gzip it is 1-9 (inclusive).

--src-registry-token token

Bearer token for accessing the source registry.

--dest-registry-token token

Bearer token for accessing the destination registry.

--dest-precompute-digests

Precompute digests to ensure layers are not uploaded that already exist on the destination registry. Layers with initially unknown digests (ex. compressing "on the fly") will be temporarily streamed to disk.

--retry-times

The number of times to retry. Retry wait time will be exponentially increased based on the number of failed attempts.

--src-username

The username to access the source registry.

--src-password

The password to access the source registry.

--dest-username

The username to access the destination registry.

--dest-password

The password to access the destination registry.

EXAMPLES

To just copy an image from one registry to another:

$ skopeo copy docker://quay.io/skopeo/stable:latest docker://registry.example.com/skopeo:latest

To copy the layers of the docker.io busybox image to a local directory:

$ mkdir -p /var/lib/images/busybox
$ skopeo copy docker://busybox:latest dir:/var/lib/images/busybox
$ ls /var/lib/images/busybox/*
  /tmp/busybox/2b8fd9751c4c0f5dd266fcae00707e67a2545ef34f9a29354585f93dac906749.tar
  /tmp/busybox/manifest.json
  /tmp/busybox/8ddc19f16526912237dd8af81971d5e4dd0587907234be2b83e249518d5b673f.tar

To create an archive consumable by docker load (but note that using a registry is almost always more efficient):

$ skopeo copy docker://busybox:latest docker-archive:archive-file.tar:busybox:latest

To copy and sign an image:

$ skopeo copy --sign-by [email protected] containers-storage:example/busybox:streaming docker://example/busybox:gold

To encrypt an image:

$ skopeo copy docker://docker.io/library/nginx:1.17.8 oci:local_nginx:1.17.8

$ openssl genrsa -out private.key 1024
$ openssl rsa -in private.key -pubout > public.key

$ skopeo copy --encryption-key jwe:./public.key oci:local_nginx:1.17.8 oci:try-encrypt:encrypted

To decrypt an image:

$ skopeo copy --decryption-key ./private.key oci:try-encrypt:encrypted oci:try-decrypt:decrypted

To copy encrypted image without decryption:

$ skopeo copy oci:try-encrypt:encrypted oci:try-encrypt-copy:encrypted

To decrypt an image that requires more than one key:

$ skopeo copy --decryption-key ./private1.key --decryption-key ./private2.key --decryption-key ./private3.key oci:try-encrypt:encrypted oci:try-decrypt:decrypted

Container images can also be partially encrypted by specifying the index of the layer. Layers are 0-indexed indices, with support for negative indexing. i.e. 0 is the first layer, -1 is the last layer.

Let's say out of 3 layers that the image docker.io/library/nginx:1.17.8 is made up of, we only want to encrypt the 2nd layer,

$ skopeo copy --encryption-key jwe:./public.key --encrypt-layer 1 oci:local_nginx:1.17.8 oci:try-encrypt:encrypted

SEE ALSO

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

AUTHORS

Antonio Murdaca [email protected], Miloslav Trmac [email protected], Jhon Honce [email protected]