Image Builder uses blueprints to create custom images.

A blueprint provides the specification for a custom image that Image Builder uses to create the image. A typical blueprint specification contains general metadata, a list of packages to install, and other customizations to apply.

Blueprints are defined in Tom's Obvious Minimal Language (TOML) format and can be created or edited in any text editor.

Blueprint definitions follow the convention parameter = "value", with package and customization definitions being grouped under [[packages]] or [[customizations]], as appropriate.

For more information about the contents of a blueprint, see Blueprint Format.

When you have created a blueprint file, you must register the blueprint with Image Builder before you can use that blueprint to create an image. See Creating a Blueprint.

When you create images based on a blueprint, those images become associated with that blueprint in the Image Builder interface of the Cockpit web console.