mkarchiso: implement configurable bootstrap tarball compression

profiledef.sh gains a new option `bootstrap_tarball_compression` which
is a bash array containing the compression program and its arguments.

Related to https://gitlab.archlinux.org/archlinux/archiso/-/issues/130.

1 files changed, 2 insertions, 0 deletions

diff --git a/docs/README.profile.rst b/docs/README.profile.rst
index 5a0c0bd..d1f6bc3 100644
--- a/docs/README.profile.rst
+++ b/docs/README.profile.rst
@@ -66,6 +66,8 @@ The image file is constructed from some of the variables in ``profiledef.sh``: `
   - ``erofs``: Create an EROFS image for the airootfs work directory
 * ``airootfs_image_tool_options``: An array of options to pass to the tool to create the airootfs image. ``mksquashfs`` and
   ``mkfs.erofs`` are supported. See ``mksquashfs --help`` or ``mkfs.erofs --help`` for all possible options
+* ``bootstrap_tarball_compression``: An array containing the compression program and arguments passed to it for
+  compressing the bootstrap tarball (defaults to ``cat``). For example: ``bootstrap_tarball_compression=(zstd -c -T0 --long -19)``.
 * ``file_permissions``: An associative array that lists files and/or directories who need specific ownership or
   permissions. The array's keys contain the path and the value is a colon separated list of owner UID, owner GID and
   access mode. E.g. ``file_permissions=(["/etc/shadow"]="0:0:400")``. When directories are listed with a trailing backslash (``/``) **all** files and directories contained within the listed directory will have the same owner UID, owner GID, and access mode applied recursively.