NAME

       runc-spec - create a new specification file

SYNOPSIS

       runc spec [option ...]

DESCRIPTION

       The spec command creates the new specification file named config.json for the bundle.

       The spec generated is just a starter file. Editing of the spec is required to achieve
       desired results. For example, the newly generated spec includes an args parameter that is
       initially set to call the sh command when the container is started. Calling sh may work
       for an ubuntu container or busybox, but will not work for containers that do not include
       the sh binary.

OPTIONS

       --bundle|-b path : Set path to the root of the bundle directory.

       --rootless : Generate a configuration for a rootless container. Note this option is
       entirely different from the global --rootless option.

EXAMPLES

       To run a simple "hello-world" container, one needs to set the args parameter in the spec
       to call hello. This can be done using sed(1), jq(1), or a text editor.

       The following commands will:
        - create a bundle for hello-world;
        - change the command to run in a container to /hello using jq(1);
        - run the hello command in a new hello-world container named container1.

              mkdir hello
              cd hello
              docker pull hello-world
              docker export $(docker create hello-world) > hello-world.tar
              mkdir rootfs
              tar -C rootfs -xf hello-world.tar
              runc spec
              jq '.process.args |= ["/hello"]' < config.json > new.json
              mv -f new.json config.json
              runc run container1

       In the run command above, container1 is the name for the instance of the container that
       you are starting. The name you provide for the container instance must be unique on your
       host.

       An alternative for generating a customized spec config is to use oci-runtime-tool; its
       sub-command oci-runtime-tool generate has lots of options that can be used to do any
       customizations as you want. See runtime-tools ⟨https://github.com/opencontainers/runtime-
       tools⟩ to get more information.

       When starting a container through runc, the latter usually needs root privileges. If not
       already running as root, you can use sudo(8), for example:

              sudo runc start container1

       Alternatively, you can start a rootless container, which has the ability to run without
       root privileges.  For this to work, the specification file needs to be adjusted
       accordingly.  You can pass the --rootless option to this command to generate a proper
       rootless spec file.

SEE ALSO

       runc-run(8), runc(8).

                                                                                  runc-spec (8"")