github.com/zhuohuang-hust/src-cbuild@v0.0.0-20230105071821-c7aab3e7c840/mergeCode/runc/man/runc-spec.8.md (about) 1 # NAME 2 runc spec - create a new specification file 3 4 # SYNOPSIS 5 runc spec [command options] [arguments...] 6 7 # DESCRIPTION 8 The spec command creates the new specification file named "config.json" for 9 the bundle. 10 11 The spec generated is just a starter file. Editing of the spec is required to 12 achieve desired results. For example, the newly generated spec includes an args 13 parameter that is initially set to call the "sh" command when the container is 14 started. Calling "sh" may work for an ubuntu container or busybox, but will not 15 work for containers that do not include the "sh" program. 16 17 # EXAMPLE 18 To run docker's hello-world container one needs to set the args parameter 19 in the spec to call hello. This can be done using the sed command or a text 20 editor. The following commands create a bundle for hello-world, change the 21 default args parameter in the spec from "sh" to "/hello", then run the hello 22 command in a new hello-world container named container1: 23 24 mkdir hello 25 cd hello 26 docker pull hello-world 27 docker export $(docker create hello-world) > hello-world.tar 28 mkdir rootfs 29 tar -C rootfs -xf hello-world.tar 30 runc spec 31 sed -i 's;"sh";"/hello";' config.json 32 runc start container1 33 34 In the start command above, "container1" is the name for the instance of the 35 container that you are starting. The name you provide for the container instance 36 must be unique on your host. 37 38 An alternative for generating a customized spec config is to use "ocitools", the 39 sub-command "ocitools generate" has lots of options that can be used to do any 40 customizations as you want, see [ocitools](https://github.com/opencontainers/ocitools) 41 to get more information. 42 43 When starting a container through runc, runc needs root privilege. If not 44 already running as root, you can use sudo to give runc root privilege. For 45 example: "sudo runc start container1" will give runc root privilege to start the 46 container on your host. 47 48 # OPTIONS 49 --bundle value, -b value path to the root of the bundle directory