libdevuansdk/docs/creating_wrappers.7.md

creating wrappers around libdevuansdk

libdevuansdk holds all the helper functions you might need, but it does not allow you to simply use it in a completely automated fashion. for that you will have to wrap some zsh around libdevuansdk.

there are a few mandatory variables that you are required to declare before sourcing libdevuansdk. otherwise libdevuansdk might write to some places of the system you wouldn't want to.

requirements

before sourcing it, libdevuansdk assumes you already loaded and initialized the zuper zsh library.

mandatory variables

• $R
  the root directory of your wrapper. in almost every situation you can set it as $PWD

• $workdir
  the working directory of the current "build". a sane default is $R/tmp/workdir

• $strapdir
  the bootstrap directory of the current "build". it holds the rootfs when you debootstrap. sane default: $workdir/rootfs

• $arch
  the CPU architecture of the current "build". values like: amd64, i386, armhf, etc...

Optional variables

• $extra_packages
  this should hold an array of packages that exist in the devuan package tree. they will get installed as a part of the bootstrap process.

• $purge_packages
  this is an array that holds a list of packages that will get removed at the final steps of the bootstrap process. note that this array is not empty by default, so you should only add to it in your wrapper, not override it. just to be safe.

• $size
  This variable will hold the value in MiB for dd to know how many zeroes it should put in the raw image.
  ex: size=1337

• $parted_type
  if you are creating a raw (dd-able) image, this variable will tell libdevuansdk how to partition that image. either dos or gpt.

• $parted_boot
  used if $parted_type=dos. it holds the values for parted and the formatting of the boot partition.
  ex: parted_boot="fat32 2048s 264191s".
  see the image_partition_raw_dos() function in libdevuansdk/zlibs/imaging for a better understanding on how the variable is used.

• $parted_root
  used if $parted_type=dos. it holds the values for parted and the formatting of the root partition.
  ex: parted_root="ext4 264192s 100%".
  see the image_partition_raw_dos() function in libdevuansdk/zlibs/imaging for a better understanding on how the variable is used.

• $gpt_boot
  used if $parted_type=gpt. it is an array holding the start and end values for partitioning the boot partition.
  ex: gpt_boot=(8192 32768)
  see the image_partition_raw_gpt() function in `libdevuansdk/zlibs/imaging for a better understanding on how the variable is used.

• $gpt_root
  used if $parted_type=gpt. it is an array holding the start value for partitioning the root partition.
  ex: gpt_root=(40960)
  currently libdevuansdk chooses this as a startpoint, and maxes out remaining available space. again, see the image_partition_raw_gpt() function for a better understanding.

• $bootfs This variable controls the file system type of the boot partition. Recognised values are none, vfat (or the synonyms fat and dos), and ext4. When none is specified, the boot partition is left raw and not mounted, so /boot becomes part of the root partition.

• $qemu_bin
  declare this if you are bootstrapping for an architecture different than yours. it should hold the path to qemu-user-static or a similarly named statically compiled qemu for userspace.