val update : Dockerfile.tupdate will run apt-get update && apt-get upgrade non-interactively.
val install : ('a, unit, string, Dockerfile.t) Stdlib.format4 -> 'ainstall fmt will apt-get update && apt-get install the packages specified by the fmt format string.
val add_user : ?uid:int -> ?gid:int -> ?sudo:bool -> string -> Dockerfile.tadd_user username will install a new user with name username and a locked password. If sudo is true then root access with no password will also be configured. The default value for sudo is false.
val dev_packages : ?extra:string -> unit -> Dockerfile.tdev_packages ?extra () will install the base development tools and sudo, passwd and git and X11. Extra packages may also be optionally supplied via extra.
val install_system_ocaml : Dockerfile.tInstall the system OCaml packages via apt-get