Red Hat's Boltron snaps together a modular Linux server

Red Hat’s ongoing experiments with making its Linux distributions more modular and flexible have yielded a new sub-distribution of Fedora.

Dubbed Fedora Boltron Server, the new prototype server project uses the various modularity technologies that Red Hat has been building into Fedora. Its goal is a Linux distribution in which multiple versions of the same system components can live and work side-by-side, non-destructively.

One of the problems Red Hat has cited with a traditional Linux distribution is that versions of the software packages shipped with the distro are typically tied to the revision of the distro itself. If you want to reliably upgrade one package, you must reliably upgrade all of its dependencies. However, in some situations, the user might need a heterogenous mix of product versions that might not be supported.

Red Hat’s Software Collections partly address this, but Red Hat wanted to implement something that worked as seamlessly as possible with the latest-generation package management system in Fedora, both for the sake of the end user and for the maintainers packaging the software.

Boltron provides a set of modules for many popular software packages – Apache HTTP Server, MariaDB, Node.js – and a number of base packages for Fedora itself. Fedora’s dnf tool is used to install packages, with different versions of packages available. Each package can have its own set of streams, or development lifecycles, which can provide one or more profiles, or predefined package sets, that include or omit components like plug-ins or optional software.

Other distributions have gone in the opposite direction, ensuring that the entire distribution and all of its packages are delivered together, immutably synched. CoreOS follows this model, with the guiding philosophy that a production-ready system needs to be tested and delivered as a single atomic unit. The approach Fedora is experimenting with in Boltron allows a user to deploy a distro with a consistent baseline if they need it, but also to deviate from the baseline without compromising the integrity of the system.

Fedora has always been a bleeding-edge, experimental playground for ideas that sometimes flowed into Red Hat Enterprise Server and CentOS. There is no guarantee that anything provided in Boltron will end up becoming part of the regular Fedora Server project, let alone RHEL. But for Linux users who would like more freedom and flexibility in their Linux distros, courageous experiments like Boltron might well point the way.