% skopeo-copy(1)

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

skopeo copy [--sign-by=key-ID] source-image destination-image

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.

--all

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.

--format, -f manifest-type Manifest type (oci, v2s1, or v2s2) to use when saving image to directory using the 'dir:' transport (default is manifest type of source)

--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 signature using that key ID for an image name corresponding to destination-image

--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] 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 ommitted otherwise.

--src-creds username[:password] for accessing the source registry

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

--dest-oci-accept-uncompressed-layers bool-value 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] 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 bool-value Access the registry anonymously.

--src-tls-verify bool-value Require HTTPS and verify certificates when talking to container source registry or daemon (defaults to true)

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

--dest-no-creds bool-value Access the registry anonymously.

--dest-tls-verify bool-value Require HTTPS and verify certificates when talking to container destination registry or daemon (defaults to true)

--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).

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 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

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

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