ryan4yin | 二花 e5b95affa6 feat(nixos): default-deny host inbound, trust the LAN/tailnet (#325)
Hosts used to trust the router as the only boundary (servers ran with the
firewall off; service ports were opened globally), so any LAN device could
reach every host service. Move filtering to the hosts as defence in depth
behind the router, which keeps its firewall on and uses a port mapping for
the few ports we actually need.

- base: nftables backend; deny inbound by default; trust the home LAN by
  source and the tailnet by interface (restrict the tailnet with ACLs);
  suppress per-service `openFirewall` global ports; allow node_exporter only
  from the monitoring host. The local podman bridge, the tailnet and the pod
  CIDRs are accepted only after the node_exporter drop.
- servers: stop disabling the firewall; drop redundant global port opens
  (caddy 80/443, NFS 2049, Jellyfin, localsend/test ports); delete the
  redundant desktop firewall module; aarch64/riscv64 import the firewall
  explicitly (akane was missing it).
- k3s: Cilium pods (10.0.0.0/8, fd00::/8) may reach host services; drop the
  flannel-era cni0/flannel.1 trust.
- youko: postgres listens on localhost + the LAN with pg_hba limited to the
  LAN; the NFS export stays LAN-scoped; remove the unauthenticated v2ray
  proxy.
- tests: `security-firewall` asserts every host runs the shared firewall, has
  the LAN CIDR rule and no global ports.
2026-09-26 14:02:03 +08:00
2026-09-21 17:24:40 +08:00
2025-08-21 15:32:50 +08:00
2023-12-19 20:45:27 +08:00
2023-07-20 20:07:08 +08:00

❄️ Ryan4Yin's Nix Config ❄️

Stargazers

My configuration is becoming more and more complex, and it will be difficult for beginners to read. If you are new to NixOS and want to know how I use NixOS, I would recommend you to take a look at the ryan4yin/nix-config/releases first, check out to some simpler older versions, such as i3-kickstarter, which will be much easier to understand.

This repository is home to the Nix code that builds all of my systems:

  1. NixOS desktops — Home Manager, Niri (Wayland), the Noctalia shell, agenix.
  2. macOS desktops — nix-darwin + Home Manager, sharing the same home/ configuration with the NixOS desktops.
  3. NixOS servers — three physical mini PCs running the VMs (libvirt and microVMs), the K3s test cluster and the self-hosted services.

See ./hosts for the host inventory, ./outputs for how the flake outputs are composed, ./BACKUP.md for the backup design, and ./AGENTS.md for the repository conventions.

Why NixOS & Flakes?

Nix allows for easy-to-manage, collaborative, reproducible deployments. This means that once something is setup and configured once, it works (almost) forever. If someone else shares their configuration, anyone else can just use it (if you really understand what you're copying/referring now).

As for Flakes, refer to Introduction to Flakes - NixOS & Nix Flakes Book

Want to know NixOS & Flakes in detail? Looking for a beginner-friendly tutorial or best practices? You don't have to go through the pain I've experienced again! Check out my NixOS & Nix Flakes Book - 🛠️ ❤️ An unofficial & opinionated 📖 for beginners!

If you're using macOS, check out ryan4yin/nix-darwin-kickstarter for a quick start.

Components

NixOS (Wayland)
Display Manager greetd + tuigreet
Window Manager Niri
Desktop Shell Noctalia — bar/notifications/launcher/lock screen/control center/power menu/screenshots, one native shell
Terminal Emulators foot, Kitty, Alacritty, Ghostty
Terminal Multiplexer Zellij
Shell Nushell + Starship
Editors / IDE Zed (GUI, primary), VS Code (GUI); Helix (TUI, primary), Neovim (TUI, backup)
Color Scheme catppuccin-nix
Networking systemd-networkd / NetworkManager
Input Method Fcitx5 + rime + 小鹤音形 flypy
System Monitor Btop (+ Noctalia's built-in sysmon widgets)
File Manager Yazi (TUI) + thunar (GUI)
Media Player mpv
Image Viewer imv
Screenshots Native Noctalia capture: region / fullscreen / display picker, with a built-in annotation editor
Screen Recording OBS, gpu-screen-recorder, wf-recorder
Fonts Nerd fonts
Filesystem & Encryption tmpfs as /, Btrfs subvolumes on a LUKS encrypted partition for persistent data; unlock via passphrase
Secure Boot lanzaboote

Wallpapers: https://github.com/ryan4yin/wallpapers

Screenshots

desktop

overview

nvim

Editors / IDE

Secrets Management

See ./secrets for details.

How to Deploy this Flake?

🔴 IMPORTANT: You should NOT deploy this flake directly on your machine ❗ It will not succeed. This flake contains my hardware configuration (such as hardware-configuration.nix, Nvidia support, etc.) which is not suitable for your hardware, and requires my private secrets repository ryan4yin/nix-secrets to deploy. You may use this repo as a reference to build your own configuration.

Run just --list to see every recipe.

For NixOS:

To deploy this flake from NixOS's official ISO image (purest installation method), please refer to ./nixos-installer/

# Desktops: deploy the <hostname>-niri nixosConfiguration (e.g. ai-niri, shoukei-niri)
just niri           # equals `sudo nixos-rebuild switch --flake .#<hostname>-niri`
just niri boot      # set as the next boot configuration without switching
just niri switch debug  # detailed output

# Other hosts (servers, VMs): deploy the nixosConfiguration matching the bare hostname
just local
just local boot
just local switch debug

For macOS (nix-darwin):

# If you are deploying for the first time,
# 1. install nix & homebrew manually.
# 2. prepare the deployment environment with essential packages available
nix-shell -p just nushell
# 3. comment home-manager's code in lib/macosSystem.nix to speed up the first deployment.

# Deploy the darwinConfiguration by hostname match (fern, frieren)
just local
just local debug  # detailed output (macOS has no switch/boot mode)

Remote / cluster hosts are deployed with Colmena on top of the same flake, e.g. just col <tag>, just k3s-test, just lab.

What y'all will need when Nix drives you to drink. (copy from hlissner's dotfiles, it really matches my feelings when I first started using NixOS...)

Validation & Development

nix develop provides the formatters and linters used by the repository. The most useful commands:

just test    # eval tests across Linux & Darwin; the output must be `true`
just fmt     # format all Nix files with nixfmt
just --list  # all recipes

nix flake check   # broader flake checks

For Nix changes, run just test and inspect just fmt's diff before committing. Non-Nix files are formatted with prettier; spelling is checked with typos.

References

Other dotfiles that inspired me:

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