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- 0413 Fix: 502 Bad Gateway from Nginx Nginx is running but could not get a valid response from your application. Read the error log, check that the app is… Intermediate · Fixes an error · Linux Article Web servers & reverse proxies 15 Oct 2026
- 0414 HTTP headers you should set on every site The response headers that make a site safer and faster: HSTS, Content-Security-Policy, X-Content-Type-Options, frame protection, Referrer-Policy, Permissions-Policy and Cache-Control, with Nginx and… Intermediate · Cheat sheet · Any system Article Making requests · Web servers & reverse proxies 15 Oct 2026
- 0418 Bash scripting fundamentals: variables, conditions, loops, functions The core building blocks of a bash script: variables and quoting, if and test, for and while loops, functions, exit codes and… Beginner · Explains an idea · Linux, macOS Article Basics · Shell scripting 15 Oct 2026
- 0419 Quoting and word splitting in bash: why “$var” and arrays save you Single quotes, double quotes, no quotes and arrays: how bash splits words and expands globs, and the small set of habits that… Intermediate · Explains an idea · Linux, macOS Article Basics · Shell scripting 15 Oct 2026
- 0420 cron and systemd timers: run something every night Schedule a script with crontab or a systemd timer: the five cron fields, environment and PATH pitfalls, logging, catching up missed runs… Beginner · Step by step · Linux Article cron & timers · Services & systemd 15 Oct 2026
- 0421 grep, sed, awk and jq: the four text tools you will use every week A working reference for the four commands that handle most text on the command line: grep finds lines, sed edits them, awk… Intermediate · Cheat sheet · Linux, macOS Article jq & JSON on the command line · Modern command-line tools · Text processing 15 Oct 2026
- 0422 Dotfiles: keep your shell setup in git Put .bashrc, .zshrc, .gitconfig and your editor settings into a git repository so a new machine is set up in minutes: a… Intermediate · Step by step · Linux, macOS Article Modern command-line tools · Setup 15 Oct 2026
- 0423 Fix: bad interpreter or command not found after a script is copied from Windows (CRLF) A script edited on Windows carries invisible carriage returns, so Linux looks for /bin/bash^M. How to spot CRLF line endings, convert them… Beginner · Fixes an error · Linux, macOS, Windows Article Basics · Shell scripting 15 Oct 2026
- 0408 What a reverse proxy is and when you need one A reverse proxy is a server that sits in front of your application, accepts requests from the internet and forwards them to… Beginner · Explains an idea · Any system Article Web servers & reverse proxies 15 Oct 2026
- 0409 Nginx as a reverse proxy with HTTPS Put Nginx in front of an app on localhost: a server block that proxies to the port, forwards the client headers, supports… Intermediate · Step by step · Linux Article Deploying sites · Web servers & reverse proxies 15 Oct 2026
- 0410 Caddy: HTTPS reverse proxy in five lines Caddy gets and renews TLS certificates on its own. Install it, write a Caddyfile with your domain and the port your app… Beginner · Step by step · Linux Article Deploying sites · Web servers & reverse proxies 15 Oct 2026
- 0411 CORS explained, and how to fix the browser error The browser blocks a request from one origin to another unless the server allows it with Access-Control headers. Fix it in the… Intermediate · Step by step · Any system, Browser Article Making requests · Web servers & reverse proxies 15 Oct 2026
- 0412 Deploy a static site: from folder to a URL Take a folder of HTML, CSS and JavaScript and publish it at your own domain with HTTPS on a small Linux server… Beginner · Guided project · Linux, macOS Article Deploying sites · Web servers & reverse proxies 15 Oct 2026
- 0387 Install Python on Linux, macOS and Windows Install a current Python 3 with pip and venv on each desktop OS, check the version, and avoid the classic traps: python… Beginner · Step by step · Linux, macOS, Windows Article Environments & packages · Installing languages & tools 15 Oct 2026
- 0388 Install Go on Linux, macOS and Windows Install the Go toolchain from the official downloads or a package manager, set PATH so the go command and installed tools are… Beginner · Step by step · Linux, macOS, Windows Article Installing languages & tools 15 Oct 2026
- 0389 Install Java (OpenJDK) on Linux, macOS and Windows Install a current long-term-support OpenJDK with the compiler included, make java and javac available on the command line, and switch between versions… Beginner · Step by step · Linux, macOS, Windows Article Installing languages & tools 15 Oct 2026
- 0390 Install Git on Linux, macOS and Windows Install Git from your package manager, Xcode's command line tools or the Windows installer, confirm the version, and do the one-time configuration… Beginner · Step by step · Linux, macOS, Windows Article Installing languages & tools · Setup 15 Oct 2026
- 0391 Install Docker on Linux, macOS and Windows Docker Desktop or Docker Engine? Pick the right one for your OS, install it, and confirm with docker run hello-world. Covers the… Beginner · Step by step · Linux, macOS, Windows Article Docker basics · Installing languages & tools 15 Oct 2026
- 0392 Install Visual Studio Code on Linux, macOS and Windows Install VS Code from Microsoft's packages, Homebrew or winget, get the code command working in the terminal, and add the extensions you… Beginner · Step by step · Linux, macOS, Windows Article Command-line tools · Installing languages & tools 15 Oct 2026
- 0393 Install PostgreSQL on Linux, macOS and Windows Install the PostgreSQL server and the psql client on each desktop OS, start the service, connect as the postgres superuser and create… Beginner · Step by step · Linux, macOS, Windows Article Install & connect · Installing languages & tools 15 Oct 2026
- 0373 Loki: ship and search logs Run Loki, Grafana Alloy and Grafana with Docker Compose, collect the systemd journal and /var/log files with a short Alloy configuration, and… Intermediate · Step by step · Linux Article Logs 15 Oct 2026
- 0394 Install kubectl on Linux, macOS and Windows Install the Kubernetes command-line client with curl, a package manager or winget, verify it, and point it at a cluster with a… Beginner · Step by step · Linux, macOS, Windows Article Concepts · Installing languages & tools 15 Oct 2026
- 0374 Alert rules that do not wake you for nothing How to design alerts people trust: alert on symptoms not causes, use for durations, separate page from ticket severities, group and inhibit… Intermediate · Explains an idea · Any system Article Alerting & dashboards 15 Oct 2026
- 0395 Install Rust on Linux, macOS and Windows Install Rust the official way with rustup, which brings rustc, cargo and future updates, make sure a C linker is present, and… Beginner · Step by step · Linux, macOS, Windows Article Installing languages & tools 15 Oct 2026
- 0375 Fix: disk full, find what is eating the space A Linux filesystem reports 100 percent used or No space left on device. Find the culprit with df and du, check journals,… Intermediate · Fixes an error · Linux Article Alerting & dashboards · Disks, LVM & filesystems 15 Oct 2026
- 0396 PowerShell basics: cmdlets, objects and the pipeline PowerShell commands are called cmdlets, they return objects instead of text, and the pipeline passes those objects between them. Once that clicks,… Beginner · Explains an idea · Linux, macOS, Windows Article PowerShell 15 Oct 2026
- 0378 Continuous integration explained What continuous integration means, why small frequent merges plus an automated build on every change prevent integration pain, what a good pipeline… Beginner · Explains an idea · Any system Article Pipelines, runners & hooks 15 Oct 2026
- 0397 PowerShell cheat sheet The PowerShell cmdlets and patterns you use every day: files, text, processes, services, filtering, exporting, remoting and the operators that trip up… Beginner · Cheat sheet · Linux, macOS, Windows Article PowerShell 15 Oct 2026
- 0379 Your first GitHub Actions workflow: run tests on every push Build a working GitHub Actions pipeline from nothing: a small Python project with a test, a workflow file that runs pytest on… Beginner · Guided project · Any system Article GitHub Actions · Pipelines, runners & hooks 15 Oct 2026
- 0380 GitHub Actions cheat sheet: triggers, matrix, secrets, caching The GitHub Actions syntax you reach for most, in copy-ready blocks: event triggers and filters, build matrices, secrets and permissions, dependency caching… Intermediate · Cheat sheet · Any system Article GitHub Actions 15 Oct 2026
- 0381 pre-commit hooks: catch mistakes before they are committed Install the pre-commit framework, configure hooks for whitespace, YAML and JSON syntax, large files, leaked private keys, Python linting and shellcheck, run… Beginner · Step by step · Linux, macOS, Windows Article Pipelines, runners & hooks · Setup 15 Oct 2026
- 0382 Fix: Resource not accessible by integration and other GitHub Actions permission errors A workflow step fails with Resource not accessible by integration, 403 on git push, or a GitHub CLI call is refused. The… Intermediate · Fixes an error · Any system Article GitHub Actions 15 Oct 2026
- 0386 Install Node.js on Linux, macOS and Windows Get Node.js and npm on any desktop OS. Use a version manager (nvm or fnm) when you work on several projects, or… Beginner · Step by step · Linux, macOS, Windows Article Installing languages & tools · Node.js 15 Oct 2026
- 0357 Keep secrets out of git: .env files, gitignore and what to do after a leak Load passwords and API keys from an untracked .env file, commit a safe .env.example instead, catch mistakes before they are pushed, and… Beginner · Step by step · Any system Article Housekeeping · Secrets & access 15 Oct 2026
- 0362 The 3-2-1 backup rule, and why a backup you never restored is not a backup Three copies, two kinds of media, one off-site: what the rule really protects against, how it maps to real tools, and why… Beginner · Explains an idea · Any system Article Strategy & restore drills 15 Oct 2026
- 0363 Restore drill: prove your backup works in 15 minutes A repeatable procedure to restore one file and one database from your newest backup into a scratch location, compare the result with… Intermediate · Step by step · Linux, macOS Article Backup tools · Strategy & restore drills 15 Oct 2026
- 0364 Schedule PostgreSQL and MySQL dumps with systemd timers Write one dump script for PostgreSQL and MySQL, run it from a systemd service and timer instead of cron, keep two weeks… Intermediate · Step by step · Linux Article Backup tools · PostgreSQL 15 Oct 2026
- 0365 Proxmox Backup Server: first setup and first restore Install Proxmox Backup Server, create a datastore and a backup user, connect it to Proxmox VE as storage, run the first VM… Intermediate · Step by step · Linux Article Backup & restore · Backup tools 15 Oct 2026
- 0371 Where are the logs? journalctl, /var/log and container logs A practical map of where Linux programs write their logs and the commands to read them: journalctl filters, the classic files under… Beginner · Step by step · Linux Article Logs 15 Oct 2026
- 0372 Grafana: your first dashboard from Prometheus data Connect Grafana to a Prometheus server, build a four-panel host dashboard with PromQL queries, set units and thresholds, add an instance variable,… Beginner · Step by step · Browser, Linux, macOS Article Prometheus & Grafana 15 Oct 2026