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)