xenial (8) runc-spec.8.gz

Provided by: runc_1.0.0~rc7+git20190403.029124da-0ubuntu1~16.04.4_amd64 bug

SYNOPSIS

       runc spec [command options] [arguments...]

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" program.

EXAMPLE

       To run docker's hello-world container one needs to set the args parameter in the spec to call hello. This
       can  be  done  using  the  sed  command  or  a  text  editor.  The following commands create a bundle for
       hello-world, change the default args parameter in the spec from "sh" to  "/hello",  then  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
              sed -i 's;"sh";"/hello";' config.json
              runc start container1

       In  the  start  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",  the  sub-command
       "oci-runtime-tool  generate"  has  lots of options that can be used to do any customizations as you want,
       see ⟨https://github.com/opencontainers/runtime-tools⟩ to get more information.

       When starting a container through runc, runc needs root privilege. If not already running  as  root,  you
       can  use  sudo to give runc root privilege. For example: "sudo runc start container1" will give runc root
       privilege to start the container on your host.

       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 parameter
       --rootless to this command to generate a proper rootless spec file.

OPTIONS

       --bundle value, -b value     path to the root of the bundle directory
          --rootless                   generate a configuration for a rootless container

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