Chapter 28. Building Custom System Images with Image Builder

Image Builder is a tool for creating custom system images. The following sections describe how to install it and how to use it.

28.1. Introduction to Image Builder

Image Builder is a tool that enables users to create customized system images of Red Hat Enterprise Linux. On Red Hat Enterprise Linux 7.6, Image Builder is available in the Extras channel as a Technology Preview in the lorax-composer package.


Image Builder is available as a Technology Preview. See the Technology Preview Features Support Scope for more details.
Customers deploying Image Builder are encouraged to provide feedback to Red Hat.

Image Builder Output Formats

Image Builder can create these output formats:
DescriptionCLI namefile extension
Ext4 File System Image
Raw Partitioned Disk Image
Live Bootable ISO
TAR Archive

Image Builder User Interfaces

The Image Builder back end runs as a system service lorax-composer. Users can interact with this service through two front ends:
  • GUI available as a web console plugin. This is the preferred method.
  • CLI available as the composer-cli tool for running commands.

Image Builder Blueprints

In Image Builder, a blueprint defines a customized system image by listing packages that will be part of the system. Blueprints can be edited and they are versioned.
When a system image is created from a blueprint, the image is associated with the blueprint in Image Builder web console interface.