标签：#Linux

Wer täglich in anspruchsvollen Agenturprojekten arbeitet und zwischen Windows-Host und Linux-Umgebung wechselt, weiß: WSL 2 ist ein Gamechanger. Doch selbst wenn man das perfekte Setup einmal konfiguriert hat, kommt unweigerlich der Moment, in dem eine Distribution hängt, RAM freigegeben werden muss oder man ein Backup ziehen will. Anstatt jedes Mal Stack Overflow zu durchsuchen, habe ich mir angewöhnt, die essenziellen Konsolen-Befehle immer griffbereit zu haben. Hier sind die 5 WSL-Befehle, die ich in meinem Setup am häufigsten brauche: Wer täglich in anspruchsvollen Agenturprojekten arbeitet und zwischen Windows-Host und Linux-Umgebung wechselt, weiß: WSL 2 ist ein Gamechanger. Doch selbst wenn man das perfekte Setup einmal konfiguriert hat, kommt unweigerlich der Moment, in dem eine Distribution hängt, RAM freigegeben werden muss oder man ein Backup ziehen will. Anstatt jedes Mal Stack Overflow zu durchsuchen, habe ich mir angewöhnt, die essenziellen Konsolen-Befehle immer griffbereit zu haben. Hier sind die 5 WSL-Befehle, die ich in meinem Setup am häufigsten brauche: 1. Den Status aller Distributionen prüfen Der absolute Standard-Befehl, um zu sehen, welche Linux-Instanzen laufen und welche WSL-Version sie nutzen. wsl --list --verbose # oder kurz: wsl -l -v 2. Der Notaus-Schalter (RAM freigeben) Wenn Docker oder ein Node-Prozess im Hintergrund den gesamten Arbeitsspeicher blockieren, fährt dieser Befehl alle WSL 2 Instanzen sauber herunter. wsl --shutdown 3. Eine bestimmte Distribution als Standard setzen Wichtig, wenn man beispielsweise neben Ubuntu noch Debian installiert hat und festlegen will, was sich beim reinen Befehl wsl öffnet. wsl --set-default <Distributionsname> 4. Die WSL-Umgebung neustarten Es gibt keinen direkten "Restart"-Befehl. Die sauberste Lösung ist das Beenden (Terminate) der spezifischen Instanz. Beim nächsten Aufruf startet sie frisch. wsl --terminate <Distributionsname> 5. IP-Adresse der WSL-Instanz herausfinden Extrem hilfreich für be

There is a moment every embedded Linux developer hits eventually. You have spent days building something that works beautifully — a sensor pipeline, a streaming server, an MQTT client — and then you reboot the device and everything is silent. Nothing started. You SSH in, manually run your script, and it all comes back to life. The hardware is fine. Your code is fine. You just have no way of automatically running it. That is the gap systemd fills. It is the init system on virtually every modern Linux distribution, and on embedded Linux systems like the Raspberry Pi it is what decides what runs at boot, what gets restarted if it crashes, and where all the logs go. Once you understand how to write a service file, your applications stop being fragile scripts you need to babysit and start being first-class system services that survive reboots, network drops, and unexpected crashes. This tutorial builds up from the simplest possible service file to a production-ready configuration, explaining every line along the way. By the end you will have a service running your own Python application, logging to the system journal, and automatically restarting itself after failures. See Complete Tutorial in Github: Systemd Services Tutorial What systemd Actually Does Before writing any configuration, it helps to understand what problem systemd is solving, because the design of service files makes much more sense once you see the underlying model. When your Raspberry Pi boots, the Linux kernel starts and immediately hands control to process ID 1 — the very first user-space process. On modern systems, that process is systemd . Everything that happens next — mounting filesystems, bringing up the network, starting your application — is orchestrated by systemd. It reads configuration files called unit files that describe what should be started, when, in what order, and what to do if something goes wrong. A service file is just one type of unit file (there are also unit files for timers, so

Just released an open-source bash checker for CIFSwitch (CVE-2026-46243) — the 19-year-old Linux kernel LPE disclosed last week that lets any unprivileged local user get root by abusing the CIFS/SPNEGO upcall path. The script runs on bare-metal, VMs, and inside containers, and is CI/CD-friendly with JSON output and clean exit codes. It checks: ✅ Kernel version against patched thresholds (6.18.22 / 6.19.12 / 7.0+) ✅ cifs-utils presence and exploitable version ✅ CIFS kernel module load state and blacklist status ✅ Unprivileged user namespace sysctl (the pivot point for the exploit) ✅ Active request-key cifs.spnego rules ✅ SELinux / AppArmor enforcement ✅ Container capabilities (CAP_SYS_ADMIN) ✅ Kernel symbol verification for the fix commit Outputs human-readable or JSON for SIEM ingestion. Exit 0 = safe, exit 1 = action needed — drop it straight into a pipeline. CIFSwitch is the fourth Linux LPE in under six weeks (after Copy Fail, Dirty Frag, and Fragnesia). If you're running multi-tenant Linux, CI runners, or container build farms, now is a good time to audit. I have also updated the cve_checks.conf in my my K8s-container_escape_audit toolkit to detect this issue.

My father worked in IT for over thirty years, and growing up around that shaped how I thought about computers. The earliest memory I have is sitting in my father's lap as he does something on his computer. One of the oldest photos I have is of me sitting on a chair in front of a computer. I grew up idolizing him. I switched to Linux when I was 12, by myself. I taught myself scripting, picked up programming basics, and spent more time in a terminal than most adults I knew. I have memories of sitting on the roof at 13 with my laptop, trying to crack my neighbor's WiFi with aircrack-ng (they were aware of my endeavors). However, growing up in a politically volatile neighborhood (Lyari) also made me politically aware and literate from a young age. With that, I developed an interest in political science and philosophy. I sat my A levels in economics and sociology, and I did not look back. For the next few years, the technical side of my life became just a habit rather than a professional direction. Then I realized I do not have to choose one or the other. I can carry on doing both. Today, I am an academic and technical editor. The social sciences gave me the writing skills: reading long blocks of dense theory, explaining abstract concepts in plain language, writing long analytical essays. And I understand technical concepts well enough to work with them seriously. I thought of synthesizing both. When I started building a technical writing portfolio, cybersecurity documentation felt like a natural place to go. Not because I had operational experience, but because I had grown up adjacent to that world. I understood the culture, the tooling, and the mindset, even if I had never worked a SOC shift. I knew I wanted to cover security documentation. Security teams produce some of the most consequential written work in any organization, and most of it is poorly structured, inconsistently formatted, or written for the person who already knows the answer rather than the person who

The Scenario: The Help Desk Bottleneck From 2019 to 2021, while serving as Lead Backend Software Engineer at a fast-growing company, I occasionally support our Linux System Administration tasks. When the DevOps team encountered a critical bottleneck during an initiative to scale dozens of new server deployments, I stepped in to streamline the infrastructure processes. The DevOps team was being hampered by constant, fragmented requests from the help desk to manually create new Linux accounts for recruits testing the latest application. These interruptions were not only time-consuming but were directly preventing the team from focusing on the high-priority infrastructure deployments that define their core responsibilities. I realized that we weren't just struggling with a task; we were struggling with a scaling bottleneck. To regain the team's focus and ensure we hit our project deadlines, I decided to automate this workflow. The First Step: The Interactive Script My first objective was to develop a robust, automated shell script to efficiently create new Linux user accounts. I started with an interactive Bash script (create-user-interactive.sh) that prompted for input. This was a good educational exercise for learning the fundamentals of Bash—like useradd, passwd, and shell variables. However, I quickly learned that while interactive scripts are great for learning, they are rarely used in professional DevOps environments. Why Manual Scripts Don’t Scale As I transitioned into a more infrastructure-focused role, I realized that manual scripts fail for three key reasons: Lack of Automation: DevOps is about "Infrastructure as Code" (IaC). Asking an engineer to sit at a terminal and type prompts is slow, error-prone, and destroys the ability to automate. Lack of Centralization: In a real team, we aren't creating users on individual local machines. We manage identity across hundreds of servers. Security Risks: Hardcoding passwords or piping them through echo is a major red

This article was originally published on aifoss.dev --- title: 'Chroma vs Qdrant vs Weaviate 2026: RAG Database Compared' description: 'Compare Chroma, Qdrant, and Weaviate for local RAG in 2026: version snapshots, filtering tradeoffs, hybrid search, quantization, and a clear pick by use case.' pubDate: 'May 27 2026' tags: ["vectordb", "ai", "rag", "python", "opensource"] The three most commonly recommended open-source vector databases for RAG — Chroma, Qdrant, and Weaviate — are not interchangeable. Chroma is a prototyping tool that grew into a real product. Qdrant is a production workhorse written in Rust with the best filtering performance of the three. Weaviate is an enterprise-grade platform with hybrid search and the most built-in integrations. Using Weaviate when you need Chroma adds unnecessary ops overhead. Using Chroma when you need Qdrant means migrating under pressure when your collection outgrows it. Versions covered: ChromaDB v1.5.9 (May 2026), Qdrant v1.17.1 (March 2026), Weaviate v1.37 (May 2026). The quick answer Situation Best choice Local prototyping, notebooks, under 100K vectors Chroma Embedded in a Python process — no separate service Chroma Production RAG with filtering-heavy queries Qdrant Multi-user deployment, concurrent queries Qdrant Memory-constrained deployment at millions of vectors Qdrant Hybrid search (BM25 + vector in one query) Weaviate Multi-modal retrieval (text + images + audio) Weaviate Built-in re-ranking or generative AI modules Weaviate Kubernetes, team-operated, agentic MCP workflows Weaviate Getting from zero to working RAG in 10 minutes Chroma What each tool actually is ChromaDB (Apache 2.0, chroma-core/chroma ) started as a pure-Python embedded database and was rebuilt in Rust for the v1.0 release. The Rust core eliminates Python's GIL bottlenecks and delivers roughly 4× faster writes and queries compared to the pre-1.0 implementation — write throughput went from ~10K to ~40K+ vectors/second in server mode. Chroma's des

Most people use these technologies every day. Almost nobody knows they exist. Every time you open YouTube, browse Instagram, join a Zoom meeting, or play an online game, your router is quietly performing a series of networking tricks behind the scenes. Those tricks have names: NAT SNAT DNAT PAT Port Forwarding They sound intimidating. They're actually much simpler than they appear. Let's break them down using something familiar: your home Wi-Fi. The Problem the Internet Had to Solve Imagine a family of five living in one house. Everyone owns a device: Laptop Phone Smart TV Gaming Console Tablet Each device needs internet access. The problem? Your Internet Service Provider usually gives you only one public IP address . Something has to manage all those devices sharing a single internet connection. That's where NAT comes in. NAT: The Receptionist of Your Network NAT stands for Network Address Translation . Think of NAT as a receptionist in an office building. People inside the building have room numbers: Laptop = Room 101 Phone = Room 102 TV = Room 103 But when communicating with the outside world, everyone uses the building's main address. The receptionist keeps track of who sent what. Your router does exactly the same thing. What Happens When You Visit Google? Inside your home: Laptop 192.168.1.10 Your router: Public IP 49.x.x.x When you open Google: 192.168.1.10 ↓ Router ↓ 49.x.x.x ↓ Google Google never sees your private IP. It only sees your router's public IP. That's NAT in action. SNAT: Changing the Sender's Address SNAT stands for Source Network Address Translation . The keyword is: Source It changes the sender's address. Before leaving your network: Source: 192.168.1.10 After SNAT: Source: 49.x.x.x The router replaces your private IP with its public IP. Without SNAT, websites wouldn't know how to send responses back to you. Real-Life Example Imagine mailing a letter. Instead of writing your bedroom number as the return address, you write the house address. Tha

When managing production enterprise infrastructure, you rarely have direct root access via SFTP or SSH for security reasons. Instead, you often have to navigate multi-layered permissions—logging in as a standard user, transferring files locally, and escalating privileges via CLI to finalize configurations. In this tutorial, we will walk through the step-by-step procedure to safely renew an Apache SSL certificate under a restricted environment where WinSCP access is limited to a non-root user (sysops), requiring command-line intervention to complete the installation. Prerequisites A target Apache web server (CentOS/RHEL-based configuration using /etc/httpd/). A standard user account (sysops) with sudo privileges. The new SSL certificate (.crt) and CA bundle/chain file ready on your local machine. Step 1: Backup Existing Certificates Before making any changes to production security files, always back up the working configuration. Access the server via PuTTY using the sysops account, and switch to the root user or use sudo to create a backup of your existing keys: sudo cp /etc/httpd/server.crt /etc/httpd/server.crt.bak sudo cp /etc/httpd/server.key /etc/httpd/server.key.bak Step 2: Stage the New Certificates via WinSCP Because your WinSCP session cannot log in directly as root, you must stage the files in a directory your user owns. Open WinSCP and log in using your sysops credentials. Upload your new certificate files (nouveau_certificat.crt and nouveau_certificat_chain.pem) directly into your home directory: /home/sysops/. Step 3: Install and Replace the Certificates Now, return to your terminal session (PuTTY) to move the files from your staging directory to the protected Apache directory using elevated privileges. Copy the new primary certificate sudo cp /home/sysops/nouveau_certificat.crt /etc/httpd/server.crt Copy the new certificate chain / CA bundle sudo cp /home/sysops/nouveau_certificat_chain.pem /etc/httpd/server-ca.crt Step 4: Verify Permissions and Ownersh

fd vs find vs ripgrep: I Created 10,000 Files to Settle This Debate TL;DR: fd is ~2.5x faster than find for filename searches, rg demolishes grep by ~3x for content searches, and find + grep combined lose on every single benchmark I ran. But there's a catch: both fd and rg skip hidden files by default, which can bite you if you're not paying attention. Here are the receipts. Why I Did This Every time someone posts a shell one-liner using find on Reddit, there's always that guy in the comments: "jUsT uSe fD, iT's fAsTeR." Then someone else chimes in with "actually ripgrep can do that too." I got tired of the anecdotes. I wanted numbers. Real ones. On real files. So I fired up WSL, generated 10,900 files across 1,506 directories (~143 MB of mixed content), and ran actual benchmarks with hyperfine . No synthetic microbenchmarks, no "I feel like X is faster" — just cold, hard terminal output. Methodology The Test Bed I created a directory at /tmp/fd-benchmark containing: Category Count Details Plain text files 2,000 file_*.txt — 20 bytes each, contains "test content line N" Binary files 2,000 data_*.bin — 15 bytes each Log files 1,500 match_*.log — contains unique "match_this_test_N" strings Config files 1,000 nested_file_*.cfg Nested dir files 1,000 level1_*/level2/level3/deep_*.txt + level1_*/shallow_*.txt Hidden root files 1,500 .hidden_* + .config_*.yml Hidden dir files 500 .hidden_dir/subdir/deep_hidden_*.txt Git objects 500 .git/objects/obj_* Multi-ext source files 800 src_*.{py,js,ts,rs,go,java,rb,php,cpp,h,css,html,json,xml,yaml,md} (50 each) Large binary files 100 large_*.dat — 1 MB each (random data) Total 10,900 $ du -sh . 143M . $ find . -type f | wc -l 10900 $ find . -type d | wc -l 1506 Tools Tested Tool Version What It Does find (GNU) 4.9.0 The OG. Ships with every Linux distro. fd 10.2.0 Rust-based find alternative. Smarter defaults, colored output. grep (GNU) 3.11 Content search. Also the OG. rg (ripgrep) 15.1.0 Rust-based grep alternative. Respects .gi

A lot of Linux incident response starts with a login question, not a malware sample. Someone sees a spike of failed SSH attempts. A root login appears in the wrong time window. A service account logs in from an address nobody recognizes. A helpdesk ticket says "the server looks weird" and the only concrete clue is a username or IP address. At that point, the useful question is not "is this host compromised?" It is more boring and more important: Did anyone actually authenticate? Which account was involved? Was it password, key, sudo, su, or a scheduled task? Was the same IP seen in web logs, current sockets, process context, or command history? Did persistence, services, packages, or recent files change near the same time? Can another responder review exactly what evidence was collected? That last point matters. If you let an AI assistant freely run shell commands during the first pass, you can get speed, but you also create a new risk: the model may over-collect, mutate the host, or produce a confident answer that nobody can audit later. For a login anomaly, I prefer a read-only evidence loop. A practical first pass Start with the narrow clue if you have one. If the alert names a user: oi login --user root -s 7d If the alert names an IP address: oi login --ip 203.0.113.44 -s 7d If the alert is vague, start wider: oi login -s 7d oi scan -s 7d The goal of the first pass is not to prove every detail. The goal is to build a timeline that a human responder can challenge. For a suspicious SSH login, I want the initial report to answer five things. 1. Authentication pattern Look for the difference between noise and access. A server can receive thousands of failed SSH attempts from the internet. That is useful background, but it is not the same as a successful session. The first split should be: failed attempts only successful login after many failures accepted key from an unusual source login by an account that normally should not be interactive root login where root SSH

Every Linux PHP developer knows the dance. You need to switch from PHP 8.1 to 8.3. You run your sudo commands, update your global symlinks, and then realize your local development server in the other window just crashed because it was running on the old version. Why should managing PHP versions be a system-wide struggle? The Solution: Per-Shell Version Isolation phpvm brings the seamless developer experience of tools like pyenv , rbenv , or nvm to the PHP ecosystem on Linux. Instead of changing /usr/bin/php globally, it uses a lightweight shim directory prepended to your PATH . When you call php , the shim inspects your environment variables and forwards the execution to the correct binary. It supports three layers of resolution, falling back gracefully: Shell pin : Pinned manually via phpvm shell <version> Project default : Resolved from .php-version or composer.json requirements when you cd into a directory Global default : The system fallback managed by update-alternatives Effortless Provisioning No need to look up repository installation guides. The built-in installer automatically detects your distribution (Ubuntu or Debian) and configures the appropriate upstream repositories (Ond?ej Sur�'s PPA or deb.sury.org ) to fetch the exact CLI and FPM packages you need. Polish in v2.5.1 Our latest release focuses on making the environment rock-solid: Tray App Auto-Start : Spawns the GTK desktop tray app immediately after installation by resolving the graphical session environment from active processes. PATH Priority : Actively prevents IDEs, login shells, or snap profiles from overriding the shim's position in PATH . Clean Cleanup : Ensures all background processes are terminated during uninstallation. Getting Started You can install or upgrade using the interactive script: curl -fsSL https://raw.githubusercontent.com/rijverse/phpvm/main/install.sh | sudo bash If you are already running v2.5.0, simply run: phpvm --self-update Check out the project website, or find the

Microsoft announced Azure Linux 4.0 and Azure Container Linux at Open Source Summit. Azure Linux 4.0 is a Fedora-based general-purpose server distribution for Azure VMs, the first time Microsoft has offered a supported Linux beyond container hosting. Azure Container Linux is an immutable container-optimized host built on Flatcar. By Steef-Jan Wiggers

When LinkedIn engineers encountered short-lived, recurring outages where the database powering their user feed became unavailable and then recover without leaving helpful traces, they had to devise a novel approach to uncover the root cause using off-CPU profiling with eBPF. By Sergio De Simone