🥇Reference: What to expect from Fedora Silverblue

Exploring the Features of an Immutable OS.

/ фото Clem Onojeghuo Unsplash

How Silverblue Came to Be

Fedora Silverblue is an immutable desktop operating system. All applications run in isolated containers, and updates are installed atomically.

Previously, the project was called Fedora Atomic Workstation. It was later renamed Silverblue. According to the developers, they considered over 150 name options. Silverblue was chosen simply because there was a free domain and social media accounts available.

The updated system replaced Fedora Workstation as the priority build for desktops in Fedora 30. The authors say that in the future, Silverblue might completely replace Fedora Workstation.

One of the residents of Hacker News suggested, that the concept of Silverblue evolved from the project Stateless Linux. It was promoted in Fedora about ten years ago. Stateless Linux was meant to simplify administration for thin and thick clients. In it, all system configuration files were also opened in 'read-only' mode.

What 'immutability' Provides

The term 'immutable operating system' indicates that the root and user directories are mounted in read-only mode. All mutable data is placed in the /var directory. A similar method is used by developers of ChromeOS and macOS Catalina. This approach enhances the security of the OS and prevents the accidental deletion of system files.

One resident of Hacker News shared in a thematic thread explained, that once they accidentally deleted several system files while modifying the Ubuntu Yaru theme. They didn't have backups due to an error in regex. According to them, an immutable OS would have helped avoid problems.

Updating is simplified as well — you just need to reboot the system with a new image. Additionally, it becomes possible to quickly switch between several branches (releases of Fedora). For instance, between the currently developed version of Fedora Rawhide and the repository updates-testing with upcoming updates.

What are the Differences from Classic Fedora

To install the base environment (/ and /usr), the OSTree technology is used. It's fair to say that this is a 'versioning' system for RPM-packages. RPM packages are streamed to the OSTree repository using rpm-ostree. When installing a package, it generates a restore point to revert to in case of failure.

OSTree also , rather than taking focus. installs applications from dnf/yum repositories and repositories not supported by Fedora. Instead of the dnf install command, rpm-ostree install should be used. The system will create a new base image of the operating system and replace the installed one.

As a mechanism for updating applications, Flatpak. It runs them in containers. A Flatpak package includes only application-specific dependencies. All base libraries (like GNOME and KDE libraries) remain connectable runtime environments. This approach reduces package size by excluding duplicate components.

/ фото Jonathan Larson Unsplash

To install applications that are not packaged in Flatpak, you can use Toolbox. It allows you to create a container with the classic Fedora installer.

Similar solutions

There are also other distributions whose tasks are similar to Silverblue. An example is MicroOS from openSUSE. It is not a standalone distribution but part of the openSUSE Kubic platform for deploying CaaS (Container as a Service).

The system works with Docker containers. Their images are distributed as RPM packages. This simplifies the installation of command-line applications that are not available in Flatpak format. The host system for running containers is formed based on the official repository openSUSE Tumbleweed.

MicroOS was developed for deployment in large-scale environments (such as data centers) but can also operate on single machines.

An example of another similar development could be . By default, a trimmed version of postmarketOS is preinstalled, designed for testing basic subsystems. The software environment can be loaded directly from the SD card without the need to carry out a firmware update.. This is a Linux distribution based on the Nix package manager. Its main feature is the declarative description of configurations. The administrator does not need to manually install and configure the system. The state is specified in a special file: it lists all packages and authentication settings. Then, the package manager automatically brings the OS to the specified state.

This system is actively use used by cloud providers, universities, and IT companies.

In any case, Silverblue has a chance to carve out its niche in the market. Whether it will succeed remains to be seen in the future.

Materials from the First blog about corporate IaaS:

Further reading on Habr:

Source: habr.com