NixOS

Author

K19G

Published

October 31, 2026

Updated

October 31, 2026

Notes on Nix & NixOS

Personal journey notes for learning Nix and NixOS the way practitioners who already live in this ecosystem would sequence the work: early feedback loops, modern defaults, depth when you have something real to debug.

Baseline: Nix 2.35.x · NixOS / nixpkgs 26.05 “Yarara” (as of mid-2026).

This is a normal topic-oriented book (parts and chapters), not a day-calendar or certification track. Chapter contract: Syllabus.

What “done” looks like

  • Explain store, derivations, evaluation vs realization, generations, and GC roots in plain language
  • Run one flake-defined NixOS 26.05 host; break it, roll back, recover
  • Prefer modern CLI + flakes as the default; recognize classic commands when you meet them
  • Separate system (NixOS) and user (Home Manager) concerns cleanly
  • Package something you actually use; write modules with real options
  • Keep secrets out of the store; layout disks with Disko when you reinstall
  • Deploy beyond one box, use a binary cache and CI, harden without cargo-cult

How the book is organized

Part Path Focus
Front matter 00-front-matter/ Syllabus, Reproducibility Crisis + Lab 0
Concepts 01-concepts/ Why Nix, store, language, CLI, flakes
Nix on Linux 02-nix-on-linux/ Fedora 44+ official Nix; dual-stack bridge to NixOS
NixOS host 03-nixos-host/ Install, rebuild, users, net, modules, boot
Home & layout 04-home-and-flake-layout/ Flake layout, locks, Home Manager, shells/editors, polyglot devShells, Docker migration
Services & security 05-services-and-security/ Secrets (SOPS/Agenix/Vault), hardening, TLS front door, containers
Packaging 06-packaging/ stdenv, overlays, caches, language ecosystems, cross-compilation, ROS 2
Ops & fleet 07-ops-and-fleet/ Disko, deploy, tests, CI, images, backups
Internals 08-internals/ Evaluator, module system, upgrades, troubleshooting
Capstone 09-capstone/ Rebuildability proof and recovery notes
CI/CD 10-cicd/ Binary caches, GitHub Actions, GitLab CI, remote builders, caching
Containers & K8s 11-containers-and-kubernetes/ Nix-built container images, K8s modules, Helm charts, Argo/Flux GitOps
IaC & Cloud 12-iac-and-cloud/ Terraform/OpenTofu with Nix, Ansible provisioning, multi-cloud
Platform Engineering 13-platform-engineering/ Internal developer platform, monorepos, Colmena fleet deploys, MicroVMs
Production Labs 14-production-labs/ Infrastructure audits, operator keys, builder factories, channel promotion
Production Capstones 15-production-capstones/ Multi-region production infrastructure deployment & Conclusion
Projects 99-projects/ Derivations + branded distro (ISO, themes, editions)
Appendices 100-appendices/ Master glossary, CLI cheatsheets, Nix language syntax reference

Chapters are topics, not “Day 1…Day 90”. Read in order when learning; use the sidebar as a reference index when you already know where to jump.

How I intend to study

Slice Share Purpose
Concept ~25% Manuals, mental models, why
Hands-on ~55% Configs and builds that can fail
Review ~20% Refactor modules, commit, write gotchas

Rules that match expert practice:

  • Disposable VM (or spare disk) for breakage; keep a daily driver safe
  • Flakes + modern CLI by default from early chapters
  • One change → rebuild → observe — avoid huge untested diffs
  • Budget disk for /nix/store
  • Pin 26.05 deliberately; upgrade only with a written plan

Prerequisites

  • Comfortable Unix shell
  • Processes, files, SSH, basic networking
  • Willingness to reinstall a VM

Formats

HTML (primary), PDF, and EPUB via the monorepo library portal when built.

Acknowledgments

Path designed as an expert learning sequence for Nix/NixOS. Topic inventory drawn from personal study notes and production practice.

Official docs (nixos.org, nix.dev, release notes) win when notes and reality disagree. No exam-vendor affiliation.