podman-image-sign - Create a signature for an image
podman image sign [options] image [image ...]
podman image sign will create a local signature for one or more local images that have been pulled from a registry. The signature will be written to a directory derived from the registry configuration files in $HOME/.config/containers/registries.d if it exists, otherwise /etc/containers/registries.d (unless overridden at compile-time), see containers-registries.d(5) for more information. By default, the signature will be written into /var/lib/containers/sigstore for root and $HOME/.local/share/containers/sigstore for non-root users
Sign all the manifests of the multi-architecture image (default false).
Path of the authentication file. Default is ${XDG_RUNTIME_DIR}/containers/auth.json, which is set using podman login. If the authorization state is not found there, $HOME/.docker/config.json is checked, which is set using docker login.
Note: There is also the option to override the default path of the authentication file by setting the REGISTRY_AUTH_FILE environment variable. This can be done with export REGISTRY_AUTH_FILE=path.
Use certificates at path (*.crt, *.cert, *.key) to connect to the registry. (Default: /etc/containers/certs.d) Please refer to containers-certs.d(5) for details. (This option is not available with the remote Podman client, including Mac and Windows (excluding WSL2) machines)
Store the signatures in the specified directory. Default: /var/lib/containers/sigstore
Print usage statement.
Override the default identity of the signature.
Sign the busybox image with the identity of foo@bar.com with a user's keyring and save the signature in /tmp/signatures/.
sudo podman image sign --sign-by foo@bar.com --directory /tmp/signatures docker://privateregistry.example.com/foobar
sudo podman image sign --authfile=/tmp/foobar.json --sign-by foo@bar.com --directory /tmp/signatures docker://privateregistry.example.com/foobar
The write (and read) location for signatures is defined in YAML-based configuration files in /etc/containers/registries.d/ for root, or $HOME/.config/containers/registries.d for non-root users. When you sign an image, Podman will use those configuration files to determine where to write the signature based on the name of the originating registry or a default storage value unless overridden with the --directory option. For example, consider the following configuration file.
docker:
privateregistry.example.com:
sigstore: file:///var/lib/containers/sigstore
When signing an image preceded with the registry name 'privateregistry.example.com', the signature will be written into sub-directories of /var/lib/containers/sigstore/privateregistry.example.com. The use of 'sigstore' also means the signature will be 'read' from that same location on a pull-related function.
containers-certs.d(5), containers-registries.d(5)
November 2018, Originally compiled by Qi Wang (qiwan at redhat dot com)