Hey guys. I know I am not good in updating my blog currently, but I have some news to share. I became father few weeks ago. Two months actually. That is the reason why I don’t update my blog so often. Don’t expect a big change in this regard anytime soon :)

But I wanted to write something at least. Last week I migrated from urxvt to xterm, because I noticed that beginning last year (2012), xterm can finally open URLs nicely. This feature was a blocker for me, since I read all my e-mails in mutt and I hate copying links.

During migration, I noticed several nice features of xterm so I decided to write a blog post about some. Let’s start.

Heute möchte ich darüber berichten, was für ein großartiges Tool wireguard ist. Ich beschreibe hier, was es macht, wie man es konfiguriert und welche Möglichkeiten sich daraus ergeben.

Wireguard wird gerne als das neue, schnelle VPN des Linux Kernels beschrieben. Dabei gibt es aber zwei Probleme. Patches liegen für den mainline Linux Kernel schon seit einiger Zeit vor. Dennoch dauern die Diskussionen um eine Aufnahme weiter an, da wireguard eine neue crypto-api einführen möchte. Zweitens vermuten Menschen unter VPN eine Lösung, die einen Client mit einem Netz oder zwei Netze untereinander verbindet, dies leistet wireguard aber gar nicht von Haus aus.

PyInstaller freezes (packages) Python applications into stand-alone executables, under Windows, GNU/Linux, Mac OS X, FreeBSD, Solaris and AIX.

PyInstaller’s main advantages over similar tools are that PyInstaller works with Python 2.7 and 3.4—3.7, it builds smaller executables thanks to transparent compression, it is fully multi-platform, and use the OS support to load the dynamic libraries, thus ensuring full compatibility

Interested in learning more about low-level specifics of the eBPF stack? Read on as we take a deep dive, from its VM mechanisms and tools, to running traces on remote, resource-constrained embedded devices.

BPF and eBPF are the same thing and the name/acronym doesn't mean much anymore because the project evolved way beyond its initial scope. BPF and eBPF are used interchangeably in the series.

Part 1 and 2 give a condensed in-depth introduction to eBPF for newcommers or those looking to further their knowledge by taking a deep dive into the lower part of the eBPF stack.
Part 3 is an overview of the userspace tooling meant to increase productivity, built on top of the low level VM mechanisms presented in parts 1 and 2.
Part 4 focuses on running eBPF programs on embedded systems which are resource constrained, where a full toolchain stack (BCC/LLVM/python/etc) is undesirable. We'll cross-compile and run eBPF programs on 32 bit ARM with smaller embedded-focused tools. Readers interested only in this part can probably skip the rest.
Part 5 is about tracing userspace: Up until now our efforts were focused on tracing the kernel, so it's about time we also examine other user processes.

containerd is available as a daemon for Linux and Windows. It manages the complete container lifecycle of its host system, from image transfer and storage to container execution and supervision to low-level storage to network attachments and beyond.

Die Freedom-Tours haben eine bewegte Geschichte hinter sich.

Als Privat-Projekt gestartet, fuhr der Bus zunächst zwei Jahre als „Linuxbus Ruhr“ von Düsseldorf durchs Ruhrgebiet nach Chemnitz zu den Chemnitzer Linux-Tagen.

Danach schlüpften wir für weitere zwei Jahre unter das Dach der FSFE, und in diesem Zuge kam es auch zur Umbenennung in Freedom Tours. Was auch der viel treffendere Name ist, denn es geht uns ja nicht allein um Linux sondern um Freie Software im allgemeinen. Und eben die Fahrt zu den Events, die sich mit Freier Software beschäftigen.

Seit diesem Jahr nun hat die FSFE Fellowship Düsseldorf die Schirmherrschaft übernommen.

Vorta is a backup client for macOS and Linux desktops. It integrates the mighty BorgBackup with your desktop environment to protect your data from disk failure, ransomware and theft.

Slurm is an open source, fault-tolerant, and highly scalable cluster management and job scheduling system for large and small Linux clusters. Slurm requires no kernel modifications for its operation and is relatively self-contained. As a cluster workload manager, Slurm has three key functions. First, it allocates exclusive and/or non-exclusive access to resources (compute nodes) to users for some duration of time so they can perform work. Second, it provides a framework for starting, executing, and monitoring work (normally a parallel job) on the set of allocated nodes. Finally, it arbitrates contention for resources by managing a queue of pending work. Optional plugins can be used for accounting, advanced reservation, gang scheduling (time sharing for parallel jobs), backfill scheduling, topology optimized resource selection, resource limits by user or bank account, and sophisticated multifactor job prioritization algorithms.

KeePassXC is a community fork of KeePassX, a native cross-platform port of KeePass Password Safe, with the goal to extend and improve it with new features and bugfixes to provide a feature-rich, fully cross-platform and modern open-source password manager.

CasparCG Server is a Windows and Linux software used to play out professional graphics, audio and video to multiple outputs as a layerbased real-time compositor. It has been in 24/7 broadcast production since 2006. And the best, it's free.
Used by most broadcasters in Europe.

Linus Torvalds transformed technology twice — first with the Linux kernel, which helps power the Internet, and again with Git, the source code management system used by developers worldwide. In a rare interview with TED Curator Chris Anderson, Torvalds discusses with remarkable openness the personality traits that prompted his unique philosophy of work, engineering and life. "I am not a visionary, I'm an engineer," Torvalds says. "I'm perfectly happy with all the people who are walking around and just staring at the clouds ... but I'm looking at the ground, and I want to fix the pothole that's right in front of me before I fall in."

Apache Pulsar is an open-source distributed pub-sub messaging system originally created at Yahoo and now part of the Apache Software Foundation

FRRouting (FRR) is an IP routing protocol suite for Linux and Unix platforms which
includes protocol daemons for BGP, IS-IS, LDP, OSPF, PIM, and RIP.

FRR’s seamless integration with the native Linux/Unix IP networking stacks
makes it applicable to a wide variety of use cases including connecting
hosts/VMs/containers to the network, advertising network services, LAN
switching and routing, Internet access routers, and Internet peering.

FRR has its roots in the Quagga project. In fact, it was started by many
long-time Quagga developers who combined their efforts to improve on
Quagga's well-established foundation in order to create the best routing
protocol stack available. We invite you to participate in the FRRouting
community and help shape the future of networking.

Join the ranks of network architects using FRR for ISPs, SaaS infrastructure,
web 2.0 businesses, hyperscale services, and Fortune 500 private clouds.

A simple shell script to tell if your Linux installation is vulnerable against the 3 "speculative execution" CVEs that were made public early 2018.
Without options, it'll inspect your currently running kernel. You can also specify a kernel image on the command line, if you'd like to inspect a kernel you're not running.
The script will do its best to detect mitigations, including backported non-vanilla patches, regardless of the advertised kernel version number.

• CVE-2017-5753
• CVE-2017-5715
• CVE-2017-5754

Nachdem die hybride Cloud aus Windows- und Linux-Systemen dank Packer und Vagrant zur Verfügung steht, soll Ansible jetzt einen Docker Swarm automatisiert initialisieren und das Deployment vorbereiten.

Eine hybride Cloud aus Windows- und Linux-Systemen kann kompliziert sein: Docker Swarm und Ansible sind jedoch zwei Tools die dabei helfen können, die Container auch über System- und Servergrenzen hinweg kontrollieren zu können.

Tired of reinventing the wheel by implementing drivers for firmware again and again.
Not with LinuxBoot!

• Liberating. The Guix System Distribution (GuixSD) is an advanced distribution of the GNU operating system developed by the GNU Project—which respects the freedom of computer users.
• Dependable. It comes with the GNU Guix package manager, which in addition to standard package management features, supports transactional upgrades and roll-backs, unprivileged package management, per-user profiles, and more.
• Hackable. It provides Guile Scheme APIs, including high-level embedded domain-specific languages (EDSLs) to define packages and whole-system configurations.

Ignition is a new provisioning utility designed specifically for CoreOS Container Linux. At the the most basic level, it is a tool for manipulating disks during early boot. This includes partitioning disks, formatting partitions, writing files (regular files, systemd units, networkd units, etc.), and configuring users. On first boot, Ignition reads its configuration from a source-of-truth (remote URL, network metadata service, hypervisor bridge, etc.) and applies the configuration.

Even though Ignition only runs once, it packs a powerful punch. Because Ignition runs so early in the boot process (in the initramfs, to be exact), it is able to accomplish configuration all before the userspace has begun booting, which enables advanced features that Container Linux admins require.