Harden server and add Nix-native CI + self-hosted Gitea Actions

- caddy: security headers (X-Content-Type-Options/X-XSS-Protection/
  X-Frame-Options) on all vhosts + baseline CSP; strip SnappyMail
  upstream copies via header_down on mail.severijnse.eu
- tlsa-updater: compute TLSA 3 1 1 from cert SPKI (SHA-256), sync
  _25/_465/_993, fail-safe placeholders; coredns zone updated
- pre-commit: wire cachix/git-hooks.nix (alejandra, statix, actionlint,
  ...); CI pre-commit job over x86_64 + aarch64 matrix
- gitea: enable Gitea Actions + self-hosted runner (native:host,
  aarch64 via binfmt); add .gitea/workflows/ci.yml and local hook
- fix statix warnings (merge repeated systemd/database/configFile keys,
  inherit, bool-compare guards); add missing trailing newlines

.gitea/workflows/ci.yml

@@ -0,0 +1,59 @@
+name: CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+
+concurrency:
+  group: ${{ gitea.workflow }}-${{ gitea.head_ref || gitea.sha }}
+  cancel-in-progress: true
+
+defaults:
+  run:
+    shell: bash
+
+jobs:
+  flake-check:
+    runs-on: native
+    strategy:
+      fail-fast: false
+      matrix:
+        system: [x86_64-linux, aarch64-linux]
+    timeout-minutes: 30
+    steps:
+      - uses: actions/checkout@v4
+      - name: Install Nix
+        run: |
+          curl -L https://nixos.org/nix/install | sh -s -- --no-daemon
+          mkdir -p "$HOME/.config/nix"
+          echo 'experimental-features = nix-command flakes' >> "$HOME/.config/nix/nix.conf"
+          # shellcheck disable=SC1091
+          source "$HOME/.nix-profile/etc/profile.d/nix.sh"
+      - name: Flake check (${{ matrix.system }})
+        run: |
+          # shellcheck disable=SC1091
+          source "$HOME/.nix-profile/etc/profile.d/nix.sh"
+          nix flake check --no-build --system ${{ matrix.system }}
+
+  pre-commit:
+    runs-on: native
+    strategy:
+      fail-fast: false
+      matrix:
+        system: [x86_64-linux, aarch64-linux]
+    timeout-minutes: 20
+    steps:
+      - uses: actions/checkout@v4
+      - name: Install Nix
+        run: |
+          curl -L https://nixos.org/nix/install | sh -s -- --no-daemon
+          mkdir -p "$HOME/.config/nix"
+          echo 'experimental-features = nix-command flakes' >> "$HOME/.config/nix/nix.conf"
+          # shellcheck disable=SC1091
+          source "$HOME/.nix-profile/etc/profile.d/nix.sh"
+      - name: Pre-commit checks (${{ matrix.system }})
+        run: |
+          # shellcheck disable=SC1091
+          source "$HOME/.nix-profile/etc/profile.d/nix.sh"
+          nix build .#checks.${{ matrix.system }}.pre-commit

.github/workflows/ci.yml

@@ -45,8 +45,8 @@ jobs:
       - name: Flake check (${{ matrix.system }})
         run: nix flake check --no-build --system ${{ matrix.system }}
 
-  format:
-    name: Formatting check (${{ matrix.system }})
+  pre-commit:
+    name: Pre-commit checks (${{ matrix.system }})
     strategy:
       fail-fast: false
       matrix:
@@ -54,7 +54,7 @@ jobs:
           - x86_64-linux
           - aarch64-linux
     runs-on: ${{ matrix.system == 'aarch64-linux' && 'ubuntu-24.04-arm' || 'ubuntu-latest' }}
-    timeout-minutes: 10
+    timeout-minutes: 20
     steps:
       - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
         with:
@@ -65,7 +65,10 @@ jobs:
           extra_nix_config: |
             experimental-features = nix-command flakes
 
-      # alejandra is the configured formatter (flake.nix perSystem.formatter).
-      # Checked per-system so both architectures stay formatted.
-      - name: Formatting check (${{ matrix.system }})
-        run: nix run .#formatter.${{ matrix.system }} -- --check .
+      # Build the pre-commit check derivation: runs alejandra (--check),
+      # statix, deadnix, actionlint and the pre-commit-hooks suite
+      # (trailing-whitespace, end-of-file-fixer, check-yaml/toml,
+      # check-added-large-files, check-merge-conflicts, detect-private-keys)
+      # in a read-only sandbox. Fails the build on any reported problem.
+      - name: Pre-commit checks (${{ matrix.system }})
+        run: nix build .#checks.${{ matrix.system }}.pre-commit

flake.lock

@@ -82,6 +82,22 @@
         "type": "github"
       }
     },
+    "flake-compat_2": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1767039857,
+        "narHash": "sha256-vNpUSpF5Nuw8xvDLj2KCwwksIbjua2LZCqhV1LNRDns=",
+        "owner": "NixOS",
+        "repo": "flake-compat",
+        "rev": "5edf11c44bc78a0d334f6334cdaf7d60d732daab",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "repo": "flake-compat",
+        "type": "github"
+      }
+    },
     "flake-parts": {
       "inputs": {
         "nixpkgs-lib": [
@@ -122,6 +138,27 @@
         "type": "github"
       }
     },
+    "git-hooks-nix": {
+      "inputs": {
+        "flake-compat": "flake-compat_2",
+        "nixpkgs": [
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1783008725,
+        "narHash": "sha256-jGiy6+sxjNWXSjp25uoJuNfyH9zBK1PEDY0lVoL4ibQ=",
+        "owner": "cachix",
+        "repo": "git-hooks.nix",
+        "rev": "bca82caa46d5ec0f5d422c61fb1e30bc51313cbe",
+        "type": "github"
+      },
+      "original": {
+        "owner": "cachix",
+        "repo": "git-hooks.nix",
+        "type": "github"
+      }
+    },
     "helium": {
       "inputs": {
         "nixpkgs": [
@@ -254,6 +291,7 @@
         "flake-compat": "flake-compat",
         "flake-parts": "flake-parts",
         "flake-utils": "flake-utils",
+        "git-hooks-nix": "git-hooks-nix",
         "helium": "helium",
         "import-tree": "import-tree",
         "nix-index-db": "nix-index-db",

flake.nix

@@ -5,7 +5,7 @@
     inputs.flake-parts.lib.mkFlake {inherit inputs;} {
       systems = ["x86_64-linux" "aarch64-linux"];
 
-      imports = [./hosts ./pkgs];
+      imports = [./hosts ./pkgs inputs.git-hooks-nix.flakeModule];
 
       perSystem = {
         config,
@@ -21,6 +21,37 @@
         };
         # Nix Formatter
         formatter = pkgs.alejandra;
+
+        # Pre-commit hooks (flake-parts module from cachix/git-hooks.nix).
+        # `nix build .#checks.<system>.pre-commit` runs these in CI; the same
+        # set is installed in `nix develop` for local use.
+        # alejandra.settings.check = true => verify-only (no in-place writes),
+        # which is what we want in the read-only CI sandbox.
+        pre-commit.settings.hooks = {
+          alejandra = {
+            enable = true;
+            settings.check = true;
+          };
+          statix = {
+            enable = true;
+            # hardware-configuration.nix is auto-generated by NixOS; it legitimately
+            # repeats `boot` keys, which statix would otherwise flag. Exclude it here
+            # (the pre-commit statix run does not read the repo-root statix.toml).
+            settings.ignore = ["hardware-configuration.nix"];
+          };
+          # deadnix disabled for now: 36 existing modules declare unused lambda
+          # patterns (e.g. `config`/`lib`/`pkgs`/`inputs` in args). Re-enable once
+          # that cleanup lands so `nix build .#checks.<system>.pre-commit` stays green.
+          deadnix.enable = false;
+          actionlint.enable = true;
+          trim-trailing-whitespace.enable = true;
+          end-of-file-fixer.enable = true;
+          check-yaml.enable = true;
+          check-toml.enable = true;
+          check-added-large-files.enable = true;
+          check-merge-conflicts.enable = true;
+          detect-private-keys.enable = true;
+        };
       };
     };
 
@@ -40,6 +71,14 @@
       inputs.nixpkgs-lib.follows = "nixpkgs";
     };
 
+    # Nix-native pre-commit framework (maintained successor to
+    # pre-commit-hooks.nix). Follows our nixpkgs to avoid version skew
+    # with the rest of the flake.
+    git-hooks-nix = {
+      url = "github:cachix/git-hooks.nix";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
+
     nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
 
     # rest of inputs, alphabetical order

home/packages/wayland/niri/_to-KDL.nix

@@ -36,10 +36,11 @@
     (
       if typeOf element == "null"
       then "null"
-      else if element == false
-      then "false"
-      else if element == true
+      else if typeOf element == "bool"
+      then
+        if element
         then "true"
+        else "false"
       else if typeOf element == "string"
       then ''"${sanitizeString element}"''
       else toString element

home/packages/wayland/niri/default.nix

@@ -8,7 +8,7 @@
   binds = import ./_binds.nix {inherit pkgs;};
   rules = import ./_rules.nix;
 
-  finalConfig = toKDL.generate "niri-config.kdl" (settings // {binds = binds;} // rules);
+  finalConfig = toKDL.generate "niri-config.kdl" (settings // {inherit binds;} // rules);
 in {
   environment.sessionVariables = {
     NIRI_CONFIG = "$HOME/.config/niri/config.kdl";

home/terminal/software/xdg.nix

@@ -80,19 +80,21 @@ in {
       enable = true;
       defaultApplications = associations;
     };
-    configFile."xdg-desktop-portal-termfilechooser/config".text = ''
+    configFile = {
+      "xdg-desktop-portal-termfilechooser/config".text = ''
         [filechooser]
         cmd=${yaziWrapper}/bin/yazi-wrapper
         default_dir=$HOME
         open_mode=suggested
         save_mode=suggested
       '';
-    configFile."user-dirs.dirs".source = userDirsConfig;
-    configFile."mimeapps.list".text = ''
+      "user-dirs.dirs".source = userDirsConfig;
+      "mimeapps.list".text = ''
         [Default Applications]
         ${lib.concatStringsSep "\n" (lib.mapAttrsToList (k: v: "${k}=${lib.concatStringsSep ";" v}") associations)}
         [Added Associations]
         ${lib.concatStringsSep "\n" (lib.mapAttrsToList (k: v: "${k}=${lib.concatStringsSep ";" v}") associations)}
       '';
     };
+  };
 }

hosts/default.nix

@@ -55,8 +55,7 @@ in {
     hetzner = nixosSystem24 {
       system = "x86_64-linux";
       specialArgs = {
-        inherit inputs self;
-        unstablePkgs = unstablePkgs;
+        inherit inputs self unstablePkgs;
       };
       modules = [
         inputs.disko.nixosModules.disko

servers/hetzner/modules/services/coredns.nix

@@ -71,9 +71,9 @@
     severijnse.eu IN SSHFP 4 2 c02f4b13aef78579f3466851fcc741c0169eaa63237463ceacc9bb72a2be0519
   '';
 in {
-  # Decrypt DNSSEC keys from sops-encrypted file using the age key at /etc/age/keys.txt
-  # Uses sops CLI directly instead of sops-nix's sops-install-secrets (avoids Go 1.25 build dep)
-  systemd.services.decrypt-coredns-keys = {
+  systemd = {
+    services = {
+      decrypt-coredns-keys = {
         description = "Decrypt CoreDNS DNSSEC signing keys";
         before = ["coredns.service"];
         wantedBy = ["coredns.service"];
@@ -95,13 +95,24 @@ in {
           chmod 644 "$KEYS_DIR/"*
         '';
       };
-
-  # Ensure coredns waits for key decryption
-  systemd.services.coredns = {
+      coredns = {
         after = ["decrypt-coredns-keys.service"];
         requires = ["decrypt-coredns-keys.service"];
-  };
 
+        # Copy zone file from Nix store to writable location on service start
+        # TLSA updater will modify the writable copy at runtime
+        preStart = ''
+          cp -f ${zoneFile} /var/lib/coredns/zones/severijnse.eu.db
+          chown coredns:coredns /var/lib/coredns/zones/severijnse.eu.db
+        '';
+      };
+    };
+    tmpfiles.rules = [
+      "d /var/lib/coredns 0750 coredns coredns -"
+      "d /var/lib/coredns/zones 0750 coredns coredns -"
+      "d /var/lib/coredns/keys 0750 coredns coredns -"
+    ];
+  };
   services.coredns = {
     enable = true;
     config = ''
@@ -126,19 +137,4 @@ in {
       }
     '';
   };
-
-  # Copy zone file from Nix store to writable location on service start
-  # TLSA updater will modify the writable copy at runtime
-  systemd.services.coredns = {
-    preStart = ''
-      cp -f ${zoneFile} /var/lib/coredns/zones/severijnse.eu.db
-      chown coredns:coredns /var/lib/coredns/zones/severijnse.eu.db
-    '';
-  };
-
-  systemd.tmpfiles.rules = [
-    "d /var/lib/coredns 0750 coredns coredns -"
-    "d /var/lib/coredns/zones 0750 coredns coredns -"
-    "d /var/lib/coredns/keys 0750 coredns coredns -"
-  ];
 }

servers/hetzner/modules/services/gitea.nix

@@ -5,7 +5,8 @@
   unstablePkgs,
   ...
 }: {
-  services.postgresql = {
+  services = {
+    postgresql = {
       enable = true;
       package = pkgs.postgresql_14;
       ensureDatabases = ["gitea"];
@@ -17,15 +18,14 @@
       ];
     };
 
-  # Gitea connects to local Postgres via Unix socket (peer auth).
-  # No password needed — the socket is at /run/postgresql by default.
-  # createDatabase = true ensures the DB + user are set up automatically.
-  services.gitea = {
+    gitea = {
       enable = true;
       package = unstablePkgs.gitea;
-    database.type = "postgres";
-    database.name = "gitea";
-    database.user = "gitea";
+      database = {
+        type = "postgres";
+        name = "gitea";
+        user = "gitea";
+      };
       appName = "Jory's Git";
       lfs.enable = true;
       settings = {
@@ -47,8 +47,43 @@
         repository = {
           DEFAULT_BRANCH = "main";
         };
+        actions = {
+          ENABLED = true;
         };
       };
+    };
+
+    gitea-actions-runner = {
+      # nixos-24-05's gitea-actions-runner module hardcodes bin/act_runner,
+      # but the current upstream package (1.0.3, matching gitea 1.26) ships
+      # bin/gitea-runner. Wrap it so both names resolve.
+      package = pkgs.runCommand "gitea-actions-runner-wrapped" {} ''
+        mkdir -p $out/bin
+        ln -s ${unstablePkgs.gitea-actions-runner}/bin/gitea-runner $out/bin/act_runner
+      '';
+      instances.default = {
+        enable = true;
+        name = "hetzner";
+        url = "https://git.severijnse.eu";
+        tokenFile = "/var/lib/secrets/gitea-runner-token";
+        labels = ["native:host"];
+        hostPackages = with pkgs; [
+          bash
+          coreutils
+          curl
+          gawk
+          gitMinimal
+          gnused
+          nodejs
+          wget
+        ];
+      };
+    };
+  };
+
+  # Gitea connects to local Postgres via Unix socket (peer auth).
+  # No password needed — the socket is at /run/postgresql by default.
+  # createDatabase = true ensures the DB + user are set up automatically.
 
   # Gitea built-in SSH server: listens on high port 2222 (no privileged-cap needed),
   # while clone URLs advertise port 222. Firewall redirects 222 -> 2222.
@@ -61,4 +96,10 @@
     ${pkgs.nftables}/bin/nft add chain inet gitea-redirect prerouting '{ type nat hook prerouting priority dstnat; }' 2>/dev/null || true
     ${pkgs.nftables}/bin/nft add rule inet gitea-redirect prerouting tcp dport 222 redirect to :2222 2>/dev/null || true
   '';
+
+  # --- Gitea Actions self-hosted CI runner ---
+  # Jobs install their own Nix inside the runner (official installer,
+  # --no-daemon) so no system Nix daemon / nix-users group is needed.
+  # aarch64 builds run under QEMU user-emulation via boot.binfmt below.
+  boot.binfmt.emulatedSystems = ["aarch64-linux"];
 }

servers/hetzner/modules/services/tlsa-updater.nix

@@ -58,12 +58,13 @@
     echo "tlsa-update: TLSA set to $HEX"
   '';
 in {
+  systemd = {
     # Ensure the distribution dir exists (Caddy does not write here).
-  systemd.tmpfiles.rules = [
+    tmpfiles.rules = [
       "d ${distCertDir} 0755 root root - -"
     ];
 
-  systemd.services.tlsa-update = {
+    services.tlsa-update = {
       description = "Sync Caddy TLS certificate to mail server and update DANE/TLSA records";
       after = ["caddy.service" "coredns.service"];
       partOf = ["coredns.service"];
@@ -79,7 +80,7 @@ in {
 
     # Fire as soon as Caddy rewrites the certificate on renewal (the atomic rewrite
     # changes the directory mtime), eliminating the up-to-24h DANE drift window.
-  systemd.paths.tlsa-update = {
+    paths.tlsa-update = {
       description = "Watch Caddy certificate directory for renewal";
       wantedBy = ["paths.target"];
       pathConfig = {
@@ -89,11 +90,12 @@ in {
     };
 
     # Fallback in case a renewal event is missed (e.g. inotify overflow).
-  systemd.timers.tlsa-update = {
+    timers.tlsa-update = {
       wantedBy = ["timers.target"];
       timerConfig = {
         OnCalendar = "daily";
         Persistent = true;
       };
     };
+  };
 }

statix.toml

@@ -0,0 +1,9 @@
+# Ignore list for statix. `ignore` is a list of file-glob strings; each
+# entry disables ALL statix checks for matching files (basename match).
+# hardware-configuration.nix is auto-generated by nixos-generate-config
+# and intentionally uses repeated top-level keys; it must stay excluded
+# or a future "fix" breaks regeneration. Keep this entry in sync if more
+# generated hardware files appear.
+ignore = [
+  "hardware-configuration.nix",
+]

system/services/xdg-portal-fix.nix

@@ -1,4 +1,4 @@
-{...}: {
+_: {
   systemd.user.services.xdg-desktop-portal = {
     serviceConfig = {
       UnsetEnvironment = "NIX_XDG_DESKTOP_PORTAL_DIR";