Introduction to Lorax

I am the Lorax. I speak for the trees [and images].

Lorax is used to build the Anaconda Installer boot.iso, it consists of a library, pylorax, a set of templates, and the lorax script. Its operation is driven by a customized set of Mako templates that lists the packages to be installed, steps to execute to remove unneeded files, and creation of the iso for all of the supported architectures.

Before Lorax

Tree building tools such as pungi and revisor rely on ‘buildinstall’ in anaconda/scripts/ to produce the boot images and other such control files in the final tree. The existing buildinstall scripts written in a mix of bash and Python are unmaintainable. Lorax is an attempt to replace them with something more flexible.


pungi and other tools call scripts/buildinstall, which in turn call other scripts to do the image building and data generation. Here’s how it currently looks:

-> buildinstall
  • process command line options
  • write temporary yum.conf to point to correct repo
  • find anaconda release RPM
  • unpack RPM, pull in those versions of upd-instroot, mk-images,,, and buildinstall

-> call upd-instroot

-> call

-> call mk-images (which figures out which mk-images.ARCH to call)

-> call

  • clean up


The existing workflow presents some problems with maintaining the scripts. First, almost all knowledge of what goes in to the stage 1 and stage 2 images lives in upd-instroot. The mk-images* scripts copy things from the root created by upd-instroot in order to build the stage 1 image, though it’s not completely clear from reading the scripts.


Create a new central driver with all information living in Python modules. Configuration files will provide the knowledge previously contained in the upd-instroot and mk-images* scripts.