レッドハットの杉村です。Ansible のテクニカルサポートをしています。 今回は以前のお問い合わせいただいた事例から、SSH (Secure Shell Protocol) について一つ紹介しようと思います。Ansible は Linux サーバを制御対象とするときは SSH で接続して処理を実行しますので、SSH の通信についてのトラブルは問題に直結します。 RHEL 8.6 + Ansible Core 2.13 で確認しています。 Ansible の基本的な動作原理 まずは Ansible はどうやって動いているのかというのを軽く振り返ってみます。 Ansible が動作するサーバをコントロールノード、制御対象をマネージドノードと呼びます。流れを大まかに説明しますと、この図のようになります。 ① YAMLで書かれたプレイブックからタスクごとに小さなプログラムを生成する ② ①で生成
5.4 Name Space When you write a small C program, you use variables which are convenient and make sense to the reader. If, on the other hand, you are writing routines which will be part of a bigger problem, any global variables you have are part of a community of other peoples’ global variables; some of the variable names can clash. When a program has lots of global variables which aren’t meaningfu
GitHub Actions Is Slowly Killing Your Engineering Team - Ian Duncan
I was an early employee at CircleCI. I have used, in anger, nearly every CI system that has ever existed. Jenkins, Travis, CircleCI, Semaphore, Drone, Concourse, Wercker (remember Wercker?), TeamCity, Bamboo, GitLab CI, CodeBuild, and probably a half dozen others I’ve mercifully forgotten. I have mass-tested these systems so that you don’t have to, and I have the scars to show for it, and I am her
GitHub Actions Is Slowly Killing Your Engineering Team - Ian Duncan
I was an early employee at CircleCI. I have used, in anger, nearly every CI system that has ever existed. Jenkins, Travis, CircleCI, Semaphore, Drone, Concourse, Wercker (remember Wercker?), TeamCity, Bamboo, GitLab CI, CodeBuild, and probably a half dozen others I’ve mercifully forgotten. I have mass-tested these systems so that you don’t have to, and I have the scars to show for it, and I am her
Update 1.69.1: The update addresses these issues. Update 1.69.2: The update addresses these issues. Downloads: Windows: x64 Arm64 | Mac: Universal Intel silicon | Linux: deb rpm tarball Arm snap Welcome to the June 2022 release of Visual Studio Code. There are many updates in this version that we hope you'll like, some of the key highlights include: 3-way merge editor - Resolve merge conflicts wit
Weird Lexical Syntax
I just learned 42 programming languages this month to build a new syntax highlighter for llamafile. I feel like I'm up to my eyeballs in programming languages right now. Now that it's halloween, I thought I'd share some of the spookiest most surprising syntax I've seen. The languages I decided to support are Ada, Assembly, BASIC, C, C#, C++, COBOL, CSS, D, FORTH, FORTRAN, Go, Haskell, HTML, Java,
The Unix shell is over 50 years old, but it still defines how programmers use their computers. We type a few words in a terminal, and milliseconds later an ephemeral factory comes online: the Unix pipeline. Data streams through a network of simple programs working concurrently, like robots on the factory floor, executing a computational choreography we composed seconds ago. Its job done, the facto
Introduction Andres Freund published the existence of the xz attack on 2024-03-29 to the public oss-security@openwall mailing list. The day before, he alerted Debian security and the (private) distros@openwall list. In his mail, he says that he dug into this after “observing a few odd symptoms around liblzma (part of the xz package) on Debian sid installations over the last weeks (logins with ssh
Nx Console VS Code Extension Compromised - StepSecurity
Update: On May 19, 2026, GitHub publicly disclosed that approximately 3,800 of its internal source code repositories were exfiltrated after an employee's device was compromised by a poisoned VS Code extension. While GitHub did not officially name the extension, Nx CEO Jeff Cross confirmed that Nx is working with Microsoft and GitHub on the impact of the malicious Nx Console version 18.95.0, and no
World’s First MIDI Shellcode Jan 2025 · 45 min read I gained remote code execution via MIDI messages to trick my synth into playing Bad Apple on its LCD. This blog post is about my journey with this reverse engineering project. Final iteration of Bad Apple The beginning I’ve had this Yamaha PSR-E433 synth for a very long time, and a couple of years ago I decided to open it up — partly because it w
How a simple Linux kernel memory corruption bug can lead to complete system compromise
In this case, reallocating the object as one of those three types didn't seem to me like a nice way forward (although it should be possible to exploit this somehow with some effort, e.g. by using count.counter to corrupt the buf field of seq_file). Also, some systems might be using the slab_nomerge kernel command line flag, which disables this merging behavior. Another approach that I didn't look
My thoughts on writing a Minecraft server from scratch (in Bash) For the past year or so, I've been thinking about writing a Minecraft server in Bash as a thought excercise. I once tried that before with the Classic protocol (the one from 2009), but I quickly realized there wasn't really a way to properly parse binary data in bash. Take the following code sample: function a() { read -n 2 uwu echo
Tier 4 Support § Support for these targets is entirely experimental. If this target is provided by LLVM, LLVM may have the target as an experimental target, which means that you need to use Zig-provided binaries for the target to be available, or build LLVM from source with special configure flags. zig targets will display the target if it is available. This target may be considered deprecated by
Table of Contents Highlights Handling of Filenames in Shell Modern C Limits & Cooperation Makefiles Logging Internationalization Minor Changes Changes Index In the 1950s, computers did not really interoperate. ARPANET has not yet happened (that would become a thing in the 60s), and every operating system was typically tied to the hardware that was meant to run on. Most communication actually happe
Making a Chess Engine in Zig
I had the honor of speaking at Systems Distributed at the end of June. Since it was hosted by TigerBeetle who is one of the largest zig users, a lot of the zig community was there. After talking to some of them, Zig seemed more interesting for me to try out. Around the same time my youtube algorithm got me hooked on chess content. I’m not a good chess player by any means, but it started giving me
In April 2026, Canonical disclosed 44 CVEs in uutils, the Rust reimplementation of GNU coreutils that ships by default since 25.10. Most of them came out of an external audit commissioned ahead of the 26.04 LTS. I read through the list and thought there’s a lot to learn from it. What’s notable is that all of these bugs landed in a production Rust codebase, written by people who knew what they were
Try Mastering Emacs for free! Are you struggling with the basics? Have you mastered movement and editing yet? When you have read Mastering Emacs you will understand Emacs. It’s that time again: there’s a new major version of Emacs and, with it, a treasure trove of new features and changes. Notable features include the formal inclusion of native compilation, a technique that will greatly speed up y
Node.js
Notable changes Add support for externally shared js builtins By default Node.js is built so that all dependencies are bundled into the Node.js binary itself. Some Node.js distributions prefer to manage dependencies externally. There are existing build options that allow dependencies with native code to be externalized. This commit adds additional options so that dependencies with JavaScript code
[PLAY WEB VERSION: ALONE] [PLAY WEB VERSION: WITH A FRIEND] [PRINT] [RULES] [SIMILAR PROJECTS] [SYMBOLS] [CREDITS] [CONTACT] [GAME HELPER ESP32 | MOBILE] [ASSEMBLY GUIDE] THE GAME I made this game to teach my daughter how buffer overflows work. My favorite part of comuting is looking at programs as something you can play with, and poke and twist and make it whatever you want. When your microwave o
Flipping Pages: An analysis of a new Linux vulnerability in nf_tables and hardened exploitation techniques
This blogpost is the next instalment of my series of hands-on no-boilerplate vulnerability research blogposts, intended for time-travellers in the future who want to do Linux kernel vulnerability research. Specifically, I hope beginners will learn from my VR workflow and the seasoned researchers will learn from my techniques. In this blogpost, I'm discussing a bug I found in nf_tables in the Linux
September 12, 2024 I wrote about how much I love fish in this blog post from 2017 and, 7 years of using it every day later, I’ve found even more reasons to love it. So I thought I’d write a new post with both the old reasons I loved it and some reasons. This came up today because I was trying to figure out why my terminal doesn’t break anymore when I cat a binary to my terminal, the answer was “fi
Screencast If you click on this screenshot, you'll see OSH running ./configure from CPython's tarball, with GC debug output. This is: 16K lines of gnarly shell generated by GNU autoconf Running in our shell interpreter, written in ~40K lines of typed Python. But, it's translated to ~80K lines of pure C++! That generated C++ runs on top of a ~4K line runtime of garbage collected data structures, an
Linux is an interpreter
This is a standalone addendum to an earlier four-part series. Reading the previous parts is not required. Links to previous parts, if you are interested: Part 0: curl > /dev/sda Part 1: Swap out the root before boot Part 2: How to pass secrets between reboots The 3rd and final part: The little chicken shed that could Part 5: you are here In a previous article, I left you with this mysterious comma
How to Write Shell Scripts in Node with Google's zx Library — SitePoint
In this article, we’ll learn what Google’s zx library provides, and how we can use it to write shell scripts with Node.js. We’ll then learn how to use the features of zx by building a command-line tool that helps us bootstrap configuration for new Node.js projects. Writing Shell Scripts: the Problem Creating a shell script — a script that’s executed by a shell such as Bash or zsh — can be a great
Symbiote: A New, Nearly-Impossible-to-Detect Linux Threat
BlackBerry Blog Symbiote: A New, Nearly-Impossible-to-Detect Linux Threat This research is a joint effort between Joakim Kennedy, Security Researcher at Intezer, and the BlackBerry Research & Intelligence Team. It can be found on the Intezer blog here as well. In biology, a symbiote is an organism that lives in symbiosis with another organism. The symbiosis can be mutually beneficial to both organ
an ssg written in shell
Inside a small POSIX SSG Earlier last year, I made this website into a JS single-page application that used two GitHub repos and did regex crimes while praying JavaScript and cross-origin resource-sharing were enabled, and it worked the way a shopping cart with two wheels still rolls downhill… So, after a few months of making and breaking different static site generators and website layouts, I’ve
Node.js — Node.js 16.17.0 (LTS)
Notable Changes Experimental command-line argument parser API Adds util.parseArgs helper for higher level command-line argument parsing. Contributed by Benjamin Coe, John Gee, Darcy Clarke, Joe Sepi, Kevin Gibbons, Aaron Casanova, Jessica Nahulan, and Jordan Harband - #42675 Experimental ESM Loader Hooks API Node.js ESM Loader hooks now support multiple custom loaders, and composition is achieved
crawshaw - 2025-06-08
How I program with Agents 2025-06-08 This is the second part of my ongoing self-education in how to adapt my programming experience to a world with computers that talk. The first part, How I program with LLMs, covered ways LLMs can be adapted into our existing tools (basically, autocomplete) and how careful prompting can replace traditional web search. Now I want to talk about the harder, and more
Django 6.0 was released today, starting another release cycle for the loved and long-lived Python web framework (now 20 years old!). It comes with a mosaic of new features, contributed to by many, some of which I am happy to have helped with. Below is my pick of highlights from the release notes. Upgrade with help from django-upgrade If you’re upgrading a project from Django 5.2 or earlier, please
research!rsc: Hash-Based Bisect Debugging in Compilers and Runtimes
Setting the Stage Does this sound familar? You make a change to a library to optimize its performance or clean up technical debt or fix a bug, only to get a bug report: some very large, incomprehensibly opaque test is now failing. Or you add a new compiler optimization with a similar result. Now you have a major debugging job in an unfamiliar code base. What if I told you that a magic wand exists
Functional Semantics in Imperative Clothing There's an old joke about programming with pure functions: “Eventually you have to do some effects. Otherwise you're just heating up the CPU.” I've always wanted the purely functional Roc programming language to be delightful for I/O-heavy use cases. But when I recently sat down to port an I/O-heavy shell script from Bash to Roc, I wasn't happy with how
GitHub - ComfyUI-Workflow/awesome-comfyui: A collection of awesome custom nodes for ComfyUI
ComfyUI-Gemini_Flash_2.0_Exp (⭐+172): A ComfyUI custom node that integrates Google's Gemini Flash 2.0 Experimental model, enabling multimodal analysis of text, images, video frames, and audio directly within ComfyUI workflows. ComfyUI-ACE_Plus (⭐+115): Custom nodes for various visual generation and editing tasks using ACE_Plus FFT Model. ComfyUI-Manager (⭐+113): ComfyUI-Manager itself is also a cu
BashFAQ - Greg's Wiki
Note: The FAQ was split into individual pages for easier editing. Also, for faster loading of this page, the answers are no longer presented here in their entirety. Readers, click the [BashFAQ/nnn] link at the bottom of each answer to read the rest of the answer. Editors, click the '[edit]' link at the bottom of each entry. Don't add new ones to this page; create a new subpage with the next availa
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Ansible の SSH の通信をデバッグする - 赤帽エンジニアブログ
The Linux Kernel Module Programming Guide
June 2022 (version 1.69)
A Shell for the Container Age: Introducing Dagger Shell | Dagger Blog
research!rsc: The xz attack shell script
World's First MIDI Shellcode
My thoughts on writing a Minecraft server from scratch (in Bash)
0.10.0 Release Notes ⚡ The Zig Programming Language
What’s New in POSIX 2024 – XCU
Bugs Rust Won't Catch | corrode Rust Consulting
What's New in Emacs 28.1?
PROJEKT: OVERFLOW
Reasons I still love the fish shell
Pictures of a Working Garbage Collector
Django: what’s new in 6.0 - Adam Johnson
Functional Semantics in Imperative Clothing