Chaos Computer Club - archive feed

Closing session of All Systems Go! 2025 Licensed to the public under https://creativecommons.org/licenses/by/4.0/de/ about this event: https://cfp.all-systems-go.io/all-systems-go-2025/talk/DR8ELH/

I overview how OS management is done at Meta. We run millions of Linux servers and we have to make sure that OS gets updated on all of them in a given period of time. To do that we developed several products: MetalOS (Image based version of CentOS), Antlir (image builder) and Rolling OS Update (a service that keeps a set of DNF repos in sync with upstream repos and uses them to update OS ) License...

The UAPI Boot Loader Specification defines conventions that let multiple operating systems and bootloaders share boot config files. So far, only systemd-boot implements it - and it’s UEFI-only by design. As a result, hybrid UEFI/BIOS images require maintaining (and keeping in sync) two sets of bootloader configs: one for systemd-boot, and one for a legacy bootloader such as syslinux. I set out to...

`test.thing` is a VM runner which targets guests using an API defined by systemd. It started after a conversation at devconf about turning `mkosi qemu` into a library. A quick intro. ~~composefs is an approach to image-mode systems without the disk images. Files are stored in a de-duplicated content-addressed storage with integrity guaranteed through fs-verity. The last year has seen an accelerati...

Updates are a critical piece of managing your fleet of devices. Nowadays, Yocto-based distributions can utilize layers for well-established update mechanisms. But, did you know that recent releases of Yocto already come with a simple update mechanism? Enter systemd-sysupdate: a mechanism capable of automatically discovering, downloading, and installing A/B-style updates. By combining it with tools...

With Bootable Containers (bootc), we can place the operating system files inside a standard OCI container. This lets users modify the content of the operating system using familiar container tools and the Containerfile pattern. They can then share those container images using container registries and sign them using cosign. Using composefs and fs-verity, we can link a UKI to a complete read only f...

S3NS is a trusted cloud operator that self-hosts Google Cloud infrastructure in France, targeting the SecNumCloud certification, the most stringent Cloud certification framework. SecNumCloud includes strict legal and operational constraints. To manage these systems securely and reproducibly, we’ve built a family of dedicated administration terminals based on the image based philosophy. These termi...

Introduce ue-rs, a fresh project that aims to be a drop-in reimplementation of update engine, written in Rust. The goal of ue-rs is to have a minimal, secure and robust implementation of update engine, required by A/B update mechanism of Flatcar Container Linux. Just like the existing update engine, it downloads OS update payloads from a Nebraska server, parses its Omaha protocol, verifies signatu...

In last year's ASG!, bootc and bootable containers were introduced. In this talk, we'll go over what changed since last year, and how Fedora CoreOS and RHEL CoreOS are leveraging bootable containers to reduce maintenance and increase sharing. Licensed to the public under https://creativecommons.org/licenses/by/4.0/de/ about this event: https://cfp.all-systems-go.io/all-systems-go-2025/talk/87TFB7/

In the Linux world there are several tools and technologies to encrypt data on a hard drive, most falling into one of two categories: block device encryption (like LUKS) or stacked filesystem encryption (like EncFs or gocryptfs). This presentation will introduce Dirlock, a new tool that belongs to a third category: native filesystem encryption, using the kernel's fscrypt API. Dirlock is currently...

Traditional package updates using tools like RPM or Zypper can introduce risks, such as incomplete updates or accidentally breaking the running system. To overcome these challenges, we developed **container-snap**, a prototype plugin designed to deliver atomic OS updates—updates that are fully applied or rolled back without compromising the system's state. container-snap leverages OCI images as th...

Last year, Lennart Poettering of the systemd fame, [gave a presentation](https://media.ccc.de/v/all-systems-go-2024-276-varlink-now-) at this very same conference, where he introduced Varlink, a modern yet simple IPC mechanism. He presented a case for Varlink, rather than [D-Bus](https://en.wikipedia.org/wiki/D-Bus) to be the future of Inter-process communication on Linux. As someone who works on...

File descriptors for processes on Linux have been available for quite some time now. Userspace has adapted them widely. Over the last two years or so we've extended the abilities of pidfds significantly. This talk will go over all the new features and deep dive into their implementation and usage. Licensed to the public under https://creativecommons.org/licenses/by/4.0/de/ about this event: https:...

CentOS Stream is especially suited for production deployments. In these environments it's often common to develop improvements to distribution packages and want to contribute them upstream. Unfortunately, until very recently that required one to then maintain their own build and deployment pipeline for the packages, at least until the changes made their way into the distribution. CentOS Proposed U...

Going for minimal containers with restricted system calls and unprivileged users is the usual Kubernetes approach these days, and it works great for most web apps. However, the development of more complex infrastructure extensions frequently hinders application functionality. While looking for a solution to deploy virtiofsd in an unprivileged container for KubeVirt, we stumbled on seccomp notifier...

GNOME has collected some very old code over the years. During the recent GNOME 49 release, we've made some drastic cleanups. Most visibly, we've dropped support for X11 and gained many dependencies on systemd. Let's explore some of the what and why for these changes! Licensed to the public under https://creativecommons.org/licenses/by/4.0/de/ about this event: https://cfp.all-systems-go.io/all-sys...

Coredumping on Linux has long been a nightmare. Currently two modes are supported: (1) Dumping directly into a file somewhere on the filesystem. (2) Dumping into a pipe connected to a usermode helper process spawned as a child of the system_unbound_wq or kthreadd. For simplicity I'm mostly ignoring (1). There's probably still some users of (1) out there but processing coredumps in this way can be...

GNOME OS is a distribution based around systemd-sysupdate. This year, we finally created a live installer image using the same /usr partition as the installed OS. The main innovation however is the ability to install without the need to reboot. The user can start working while the installation is happening. This live image is built using systemd-repart. And the installer itself also uses systemd-r...

It has been 10 years since Axis Communications had a presentation at the systemd conference. Back then, we have shown how we have increased our product quality, stability and boot times by porting our platform to systemd. 10 years later, we had different challenges to keep the resource usages and boot times under control. We have started from bottom up and sliced our software for this purpose. Thi...

Flatpak is the de-facto standard for distributing desktop applications across various Linux based systems. It also offers other advantages such as sandboxing. It is particularly useful for image based systems as it installs the applications into a separate location and doesn't try to modify the system. GNOME OS is GNOME's development, testing and QA operating system. It builds the latest and great...

Many traditional container engines make use of the "subuid" concept and the "newuidmap" tool to implement a concept of "unprivileged" user-namespace containers on Linux. This approach has many shortcomings in my PoV, from both a security and scalability standpoint. Recent systemd versions provide a more powerful, more secure, mor scalable alternative, via systemd-nsresourced, systemd-mountfsd and...

oo7-daemon is the new D-Bus Secret Service provider that aims to fully replace gnome-keyring. In this followup (continuation of my 2024 talk) lightning talk, I will go through the progress made, the challenges faced and the status of systemd credentials integration. Licensed to the public under https://creativecommons.org/licenses/by/4.0/de/ about this event: https://cfp.all-systems-go.io/all-syst...

Marco will review the features available in the initramfs-tools ecosystem, the initrd generator used by Debian and Ubuntu, and how they can be implemented (or not) by adopting mkosi-initrd. Licensed to the public under https://creativecommons.org/licenses/by/4.0/de/ about this event: https://cfp.all-systems-go.io/all-systems-go-2025/talk/E989ZX/

At Meta, we've been looking to revamp our internal container runtime (Twine). Instead of maintaining all the low level container runtime code ourselves, we'd much prefer having more of this managed by systemd. This talk will go over what we did to make systemd transient units a suitable environment for running system containers (pid namespace support, cgroup namespace support, namespace delegation...

Simplify systemd management with `isd`! `isd` is a TUI offering fuzzy search for units, auto-refreshing previews, smart sudo handling, and a fully customizable interface for power-users and newcomers alike. If you ever became frustrated while typing: - `systemctl start --user unit-A.service` (manually starting a unit) - `systemctl status --user unit-A.service` (seeing that it failed) - `journalctl...