umoci-raw-unpack(1)(#) unpack umoci-raw-unpack(1)(#)
Aleksa Sarai SEPTEMBER 2018

umoci raw unpack - Unpacks an OCI image tag into a root filesystem

umoci raw unpack [umoci-unpack(1) flags] rootfs

Extracts all of the layers (deterministically) to a root filesystem at path rootfs. This path must not already exist.

The global options are defined in umoci(1), while the options for this particular subcommand are identical to umoci-unpack(1) with the exception that the rootfs path is provided rather than a bundle path.

The following downloads an image from a docker(1) registry using skopeo(1), unpacks said image to a root filesystem, generates an OCI runtime configuration file with umoci-raw-runtime-config(1) and then creates a new container with runc(8).

% skopeo copy docker://opensuse/amd64:42.2 oci:image:latest
# umoci raw unpack --image image rootfs
# umoci raw runtime-config --image image --rootfs rootfs config.json
# runc run ctr
[ container session ]

With --rootless it is also possible to do the above example without root privileges. umoci will generate a configuration that works with rootless containers in runc(8).

% skopeo copy docker://opensuse/amd64:42.2 oci:image:latest
% umoci raw unpack --image image --rootless rootfs
% umoci raw runtime-config --image image --rootfs rootfs --rootless config.json
% runc --root $HOME/runc run ctr
[ rootless container session ]

umoci(1), umoci-raw-runtime-config(1), runc(8)

umoci raw