osbuild-composer - Man Page

OSBuild Composer Service


The composer project is a set of HTTP services for composing operating system images. It builds on the pipeline execution engine of osbuild [1] and defines its own class of images that it supports building.

Multiple APIs are available to access a composer service. This includes support for the lorax-composer [2] API, and as such can serve as drop-in replacement for lorax-composer.

You can control a composer instance either directly via the provided APIs, or through higher-level user-interfaces from external projects. This, for instance, includes a Cockpit Module [3] or using the composer-cli [4] command-line tool.


Composer does not ship with frontends itself. However, several external frontends for Composer already exist. These include:

Cockpit Composer

This module for Cockpit [5] allows a great level of control of a Composer instance running on a cockpit-managed machine.

Composer CLI

This command-line tool originated in the lorax [2] project, but can be used with Composer just as well.


To deploy a composer instance, all you need is to

# systemctl start osbuild-composer.socket

Now you can access the service using composer-cli, for example:

# composer-cli status show

or using Cockpit with the Cockpit Composer module from a browser: http://localhost:9090

See Also

osbuild(1), osbuild-manifest(5)



OSBuild: https://www.osbuild.org


Lorax Composer: https://github.com/weldr/lorax


Cockpit Composer: https://github.com/osbuild/cockpit-composer


Composer CLI: https://weldr.io/lorax/composer-cli.html


Cockpit Project: https://www.cockpit-project.org/