NAME

       umoci raw runtime-config - Generate an OCI runtime configuration for an image

SYNOPSIS

       umoci raw runtime-config --image=image[:tag] [--rootfs=rootfs] [--rootless] config

       umoci raw config --image=image[:tag] [--rootfs=rootfs] [--rootless] config

DESCRIPTION

       Generate  a  new OCI runtime configuration from an image, without extracting the rootfs of
       said image. The configuration is written to the path given by config, overwriting it if it
       exists  already. This is one of the operations done by umoci-unpack(1) when generating the
       runtime  bundle,  but  because  of  the  overhead  of  extracting   a   root   filesystem,
       umoci-unpack(1)  is  not practical to be used many times if the user doesn't actually want
       to use the root filesystem. Some fields require a root filesystem as a "source of  truth",
       and  a  source  root  filesystem can be specified using --rootfs. The other flags have the
       same effects as with umoci-unpack(1).

       Note however that the output of umoci-raw-runtime-config(1) is not  necessarily  identical
       to  the output from umoci-unpack(1). This is especially true if --rootfs is not specified,
       which results in umoci(1) leaving  fields  in  the  runtime  spec  to  their  defaults  if
       computing their values would require using the root filesystem as a source-of-truth.

OPTIONS

       The global options are defined in umoci(1).

       --image=image[:tag]
         The OCI image tag which will be extracted to the bundle. image must be a
         path to a valid OCI image and tag must be a valid tag in the image. If
         tag is not provided it defaults to "latest".

       --rootfs=rootfs
         Use rootfs as a secondary source of truth when generating the runtime
         configuration (this is especially important for Config.User conversion). If
         unspecified, any runtime fields that require a secondary source of truth to
         be filled with be left in their default values. This may result in
         discrepancies between the output of umoci-unpack(1) and
         umoci-raw-runtime-config(1).

       --rootless
         Generate a rootless container configuration, similar to the configuration
         produced by umoci-unpack(1) when provided the --rootless flag.

EXAMPLE

       The  following  downloads  an  image  from  a  docker(1) registry using skopeo(1) and then
       generates the config.json for that image.

              % skopeo copy docker://opensuse/amd64:42.2 oci:image:latest
              % umoci raw runtime-config --image image:latest config.json

       If a root filesystem is already present, it is possible to specify it  with  the  --rootfs
       flag. This will source the root filesystem for conversion operations that necessitate it.

              % skopeo copy docker://opensuse/amd64:42.2 oci:image:latest
              # umoci unpack --image image bundle
              % umoci raw runtime-config --image image --rootfs bundle/rootfs config.json

SEE ALSO

       umoci(1), umoci-repack(1), runc(8)