Articles
Explanations, step-by-step guides, cheat sheets and fixes. Pick an area, or tell us what you need.
What kind of help
What do these mean?
- Beginner
- You are new to this topic.
- Intermediate
- You use it, and want to get better.
- Advanced
- You know it well and need the details.
- Guided project
- Build something small from start to finish, step by step.
- Explains an idea
- Plain words on how something works and why.
- Step by step
- Numbered steps to get one task done.
- Cheat sheet
- Commands and options in a table, to look up fast.
- Fixes an error
- An error message, what it means, and how to solve it.
Area
Clear filters
19 entries match these filters
- 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
- 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
- 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
- 0346 The SSH config file: aliases, jump hosts and keys per server Reference for ~/.ssh/config: short names for servers, the right user, port and key per host, ProxyJump through a bastion, connection reuse and… Intermediate · Cheat sheet · Linux, macOS, Windows Article Keys & config · SSH 15 Oct 2026
- 0329 Docker CLI cheat sheet The Docker commands you reach for every day, grouped by what they act on: containers, images, volumes, networks, logs and cleanup, with… Beginner · Cheat sheet · Linux, macOS, Windows Article Docker basics 15 Oct 2026
- 0232 mongosh cheat sheet: CRUD, indexes and explain() The mongosh commands you use every day: switching databases, inserting, querying, updating and deleting documents, creating indexes and checking a query plan… Beginner · Cheat sheet · Any system Article Basics 15 Oct 2026
- 0236 Redis data types and commands: a quick reference Redis stores values under keys, and each value has a type: string, hash, list, set, sorted set or stream. The essential commands… Beginner · Cheat sheet · Any system Article Basics 15 Oct 2026
- 0215 mysql command-line client cheat sheet The connection options, built-in commands and everyday SQL you need in the mysql (and mariadb) command-line client, on one page. Beginner · Cheat sheet · Any system Article Administration · Queries 15 Oct 2026
- 0222 Connecting to Oracle: SQL*Plus, SQLcl, EZConnect, tnsnames.ora and the listener Clients reach an Oracle database through the listener, using an Easy Connect string or a tnsnames.ora alias. Here are the formats, the… Intermediate · Cheat sheet · Linux, macOS, Windows Article Administration · Concepts & tools 15 Oct 2026
- 0199 psql meta-commands cheat sheet The backslash commands you use every day in psql: connecting, listing databases, tables and roles, describing objects, timing queries, expanded output and… Beginner · Cheat sheet · Any system Article Install & connect · Roles & administration 15 Oct 2026
- 0140 kubectl cheat sheet: the commands you use every day A compact reference of everyday kubectl commands: contexts and namespaces, listing and inspecting objects, logs and exec, applying changes, rollouts, scaling and… Beginner · Cheat sheet · Any system Article Concepts · Troubleshooting 15 Oct 2026
- 0157 oc cheat sheet: everyday OpenShift CLI commands The oc commands you use every day, grouped by task: login and projects, apps and builds, routes, config, debugging, permissions and admin… Intermediate · Cheat sheet · Any system Article Deploying applications · Troubleshooting 15 Oct 2026
- 0121 PCA 3.x Service CLI basics: connecting and finding your way around The Service CLI administers the Private Cloud Appliance 3.x Service Enclave. Connect with SSH on port 30006 and use list, show, help,… Intermediate · Cheat sheet · Any system Article Administration & monitoring 15 Oct 2026
- 0082 HTTP status codes: the common ones and what to do A quick reference to the HTTP status codes you will meet most often, what each one means, and the first thing to… Beginner · Cheat sheet · Any system Article References · Status codes 15 Oct 2026
- 0037 Git cheat sheet The Git commands you reach for most, grouped by task and using the modern switch and restore forms. Copy, paste, and replace… Beginner · Cheat sheet · Any system Article Git 15 Oct 2026
- 0017 JavaScript array methods cheat sheet: map, filter, reduce and friends A quick reference for the array methods you use every day, with what each one returns and whether it changes the original… Beginner · Cheat sheet · Any system Article Basics 15 Oct 2026
- 0025 Regular expressions cheat sheet (JavaScript flavor) The regex syntax you actually use, from character classes and quantifiers to groups, lookarounds and flags, with the JavaScript methods that apply… Beginner · Cheat sheet · Any system Article Basics · Basics 15 Oct 2026
- 0002 Python cheat sheet: strings, lists, dicts and f-strings The everyday methods for text, lists and dictionaries, plus f-string formatting and comprehensions, each with a one-line example you can paste into… Beginner · Cheat sheet · Any system Article Basics 15 Oct 2026
- 0003 pathlib cheat sheet: files and folders in Python pathlib.Path is the modern way to build paths, read and write files, and list or search folders in Python. This page lists… Beginner · Cheat sheet · Any system Article Files & automation 15 Oct 2026