authelia added

modules/server/authelia.nix

@@ -0,0 +1,200 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+# Authelia — SSO reverse-proxy (single-factor password login) for protected
+# vhosts. Uses nixpkgs' services.authelia module (a native systemd unit with
+# hard sandboxing) instead of a podman container — Authelia is a Go binary,
+# not a foreign distro, so a container adds nothing but surface area.
+#
+# Wiring:
+#   - The internal API listens on 127.0.0.1:9091 only (overrides the nixpkgs
+#     default `tcp://:9091/` which would bind all interfaces).
+#   - Three secrets (jwt, storage encryption key, users_database) come from
+#     modules/server/secrets/authelia.yaml via sops-nix, materialised at
+#     /run/secrets/<name> by the time authelia.service starts.
+#   - nginx is the only ingress: authelia.zeroq.su vhosts the login UI and
+#     every protected vhost (currently vtimeline.zeroq.su) does
+#     `auth_request /authelia` against 127.0.0.1:9091 (see nginx.nix).
+#   - users_database.yml is symlinked into /var/lib/authelia/ so the path
+#     configured in `settings.authentication_backend.file.path` resolves
+#     to the sops materialised file. The symlink target is created by
+#     sops-nix before this unit starts, so no race.
+#
+# Version: pinned transitively via flake inputs.nixpkgs → pkgs.authelia.
+# `nix flake update` will roll it forward; no overlay needed.
+#
+# Secrets layout in modules/server/secrets/authelia.yaml (sops-encrypted):
+#   jwt_secret              -> /run/secrets/authelia-jwt-secret
+#   storage_encryption_key  -> /run/secrets/authelia-storage-encryption-key
+#   users_database          -> /run/secrets/authelia-users-database
+#                              (multiline YAML string, written verbatim by
+#                               sops-nix and consumed as a settingsFile)
+#
+# Guarded by `builtins.pathExists` so a missing sops file does NOT break
+# `nixos-rebuild switch` — the flake evaluates, Authelia stays disabled
+# until the secret file is created and encrypted.
+let
+  cfg = config.host.authelia;
+  sopsReady = builtins.pathExists ./secrets/authelia.yaml;
+  # sops-nix materialises each `sops.secrets.<attr-name>` at
+  # /run/secrets/<attr-name> by default. Hardcoding the path here keeps
+  # the module independent of how the secret attr is named; rename only
+  # the sops block below if a different path is needed.
+  sopsPath = name: "/run/secrets/${name}";
+in
+{
+  options.host.authelia = {
+    enable = lib.mkEnableOption ''
+      Authelia SSO reverse-proxy. When enabled, exposes the internal API on
+      127.0.0.1:9091 (loopback only — nginx is the only ingress). Activating
+      this option requires modules/server/secrets/authelia.yaml to exist
+      and decrypt successfully; otherwise the toplevel build fails on a
+      missing sopsFile.
+    '';
+    cookieDomain = lib.mkOption {
+      type = lib.types.str;
+      default = "zeroq.su";
+      description = ''
+        Domain scope for Authelia session cookies and the login-UI vhost
+        (`authelia.<cookieDomain>`). All protected vhosts must be subdomains
+        of this value for the session cookie to flow through nginx's
+        auth_request handshake.
+      '';
+    };
+    autheliaFqdn = lib.mkOption {
+      type = lib.types.str;
+      default = "authelia.${cfg.cookieDomain}";
+      description = ''
+        Public FQDN where the Authelia login UI is served by nginx. Set this
+        to override the default (authelia.<cookieDomain>) when a CNAME or a
+        different deployment shape requires it.
+      '';
+    };
+  };
+
+  config = lib.mkIf cfg.enable {
+    services.authelia.instances."" = {
+      enable = true;
+      # Default is already pkgs.authelia; pinned here for clarity and to
+      # give an obvious handle for future overrides (e.g. an overlay to
+      # hold a specific upstream version during CVE windows).
+      package = pkgs.authelia;
+
+      secrets = lib.mkIf sopsReady {
+        jwtSecretFile = sopsPath "authelia-jwt-secret";
+        storageEncryptionKeyFile = sopsPath "authelia-storage-encryption-key";
+      };
+
+      settings = {
+        # Override the nixpkgs default (`tcp://:9091/`) — binding all
+        # interfaces would expose the API to the LAN. nginx is the only
+        # allowed ingress, talking to 127.0.0.1:9091.
+        server.address = "tcp://127.0.0.1:9091";
+        log = {
+          level = "info";
+          format = "text";
+        };
+        authentication_backend.file = {
+          # Read directly from the sops materialised file at /run/secrets/.
+          # Authelia does NOT validate-config this path — it only opens it
+          # when verifying a user password (lazy read). Putting the same
+          # file into settingsFiles would force viper to parse it as
+          # configuration, and the `users:` top-level key would fail the
+          # schema check (users.* is schema-foreign).
+          path = sopsPath "authelia-users-database";
+          password = {
+            algorithm = "argon2id";
+            iterations = 3;
+            salt_length = 16;
+            parallelism = 4;
+            memory = 65536;
+          };
+        };
+        storage.local.path = "/var/lib/authelia/db.sqlite3";
+        session = {
+          expiration = "1h";
+          inactivity = "5m";
+          cookies = [
+            {
+              domain = cfg.cookieDomain;
+              authelia_url = "https://${cfg.autheliaFqdn}/";
+            }
+          ];
+        };
+        access_control = {
+          default_policy = "deny";
+          rules = [
+            {
+              # Catch-all for any vhost that talks to Authelia without an
+              # explicit rule still gets one_factor. Per-vhost tightening
+              # is layered in nginx.nix (the vhost just omits auth_request
+              # to opt out).
+              domain = "*";
+              policy = "one_factor";
+            }
+          ];
+        };
+        notifier = {
+          disable_startup_check = true;
+          filesystem.filename = "/var/lib/authelia/notifier.txt";
+        };
+      };
+
+      # No `settingsFiles` — the users_database file is read directly
+      # via `settings.authentication_backend.file.path` above. Adding
+      # it here would put `users:` under viper's config schema check
+      # (validate-config), which rejects it as an unknown top-level key.
+    };
+
+    # Wait for sops-nix to materialise the secrets before Authelia starts.
+    # Without this, authelia can race ahead of sops and read an empty
+    # /run/secrets on the very first boot after a switch. Existing boots
+    # (when /run/secrets is already populated) skip the wait instantly.
+    # `sops-nix.service` is the systemd service that the sops-nix module
+    # creates to deploy credentials; depending on its name avoids the
+    # "race between tmpfiles-setup and the sops materialiser" that the
+    # previous tmpfiles-symlink design implicitly relied on.
+    systemd.services.authelia.after = [ "sops-nix.service" ];
+    systemd.services.authelia.wants = [ "sops-nix.service" ];
+
+    # sops wiring. Guarded by builtins.pathExists so the flake still
+    # evaluates when ./secrets/authelia.yaml hasn't been created yet —
+    # a clean checkout would otherwise fail every nixos-rebuild switch.
+    # Once the file exists and is encrypted, this condition becomes true
+    # and the three secrets are wired in.
+    sops.secrets = lib.optionalAttrs sopsReady {
+      "authelia-jwt-secret" = {
+        format = "yaml";
+        key = "jwt_secret";
+        sopsFile = ./secrets/authelia.yaml;
+        owner = "authelia";
+        group = "authelia";
+        mode = "0400";
+      };
+      "authelia-storage-encryption-key" = {
+        format = "yaml";
+        key = "storage_encryption_key";
+        sopsFile = ./secrets/authelia.yaml;
+        owner = "authelia";
+        group = "authelia";
+        mode = "0400";
+      };
+      # users_database is a multiline YAML string in the sops file
+      # (top-level `users_database: |` block with `users: <name>: ...`
+      # beneath). sops-nix writes the decoded block verbatim to
+      # /run/secrets/authelia-users-database, where the symlink rule
+      # above makes it appear at /var/lib/authelia/users_database.yml.
+      "authelia-users-database" = {
+        format = "yaml";
+        key = "users_database";
+        sopsFile = ./secrets/authelia.yaml;
+        owner = "authelia";
+        group = "authelia";
+        mode = "0400";
+      };
+    };
+  };
+}

modules/server/coredns.nix

@@ -10,6 +10,7 @@
       zeroq.su:53 {
           hosts {
               109.248.161.5 x.zeroq.su
+              192.168.1.20 authelia.zeroq.su
               192.168.1.20 calibre.zeroq.su
               192.168.1.20 dns.zeroq.su
               192.168.1.20 flux.zeroq.su

modules/server/default.nix

@@ -10,6 +10,7 @@
     ../containers/tape-rotation.nix
     ../pkgs/beets.nix
     ./acme.nix
+    ./authelia.nix
     ./bentopdf.nix
     ./builder.nix
     ./calibre-web.nix
@@ -52,6 +53,13 @@
   # case 3x-ui is later reconfigured to terminate TLS itself (e.g. for
   # direct node-API access); nginx doesn't have to use it.
   host."3x-ui".certDomain = "x.zeroq.su";
+  # Authelia SSO — currently protects vtimeline.zeroq.su (replaces the
+  # previous nginx auth_basic htpasswd). Cookie domain is .zeroq.su so a
+  # single Authelia session covers every protected vhost under the zone.
+  host.authelia = {
+    enable = true;
+    cookieDomain = "zeroq.su";
+  };
   systemd.tmpfiles.rules = [
     (xlib.helpers.mkTmpfile "d" "/mnt" "0755" "root" "root")
     (xlib.helpers.mkTmpfile "d" xlib.dirs.services-mnt-folder "0755" "root" "root")

modules/server/nginx.nix

@@ -123,21 +123,55 @@ in
         forceSSL = true;
         enableACME = true;
       };
-      # vtimeline.zeroq.su — static site behind HTTP basic auth.
+      # vtimeline.zeroq.su — static site behind Authelia forward-auth.
       # Files live under /home/oqyude/External/Git/VeeamTimelineView/public_html,
       # which is bind-mounted to /var/lib/vtimeline (see systemd.mounts below)
       # because /home/oqyude is mode 700 and the nginx user (uid 60) cannot
-      # traverse it. Credentials are pulled from sops; see the sops.secrets
+      # traverse it. Authentication is delegated to Authelia via
-      # block at the bottom of this file.
+      # auth_request: nginx sub-requests /authelia on every hit, Authelia
+      # returns 2xx if the session cookie is valid or 401 (which nginx
+      # converts into a 401 to the client; Authelia's response headers
+      # carry the redirect target). The login UI itself is served by the
+      # authelia.zeroq.su vhost below — same Authelia container, different
+      # vhost.
       "vtimeline.zeroq.su" = {
         forceSSL = true;
         enableACME = true;
         root = "/var/lib/vtimeline";
+        locations = {
+          "/" = {
             extraConfig = ''
-          auth_basic "vtimeline";
+              auth_request /authelia;
-          auth_basic_user_file ${config.sops.secrets.vtimeline-htpasswd.path};
+              auth_request_set $authelia_user $upstream_http_remote_user;
             '';
           };
+          "= /authelia" = {
+            extraConfig = ''
+              internal;
+              proxy_pass http://127.0.0.1:9091/api/authz/forward-auth;
+              proxy_set_header X-Original-URL $request_uri;
+              proxy_set_header X-Forwarded-Proto $scheme;
+              proxy_set_header X-Forwarded-Host $host;
+              proxy_set_header X-Forwarded-Method $request_method;
+              proxy_set_header X-Forwarded-Uri $request_uri;
+              proxy_set_header X-Forwarded-For $remote_addr;
+            '';
+          };
+        };
+      };
+      # Authelia login UI — same podman container on 127.0.0.1:9091 as the
+      # forward-auth endpoint above, just exposed on a separate vhost so
+      # Authelia has a stable absolute URL to redirect users to. Authelia
+      # generates internal links against $session.cookies[0].authelia_url,
+      # which is set to https://${autheliaFqdn}/ in modules/server/authelia.nix.
+      "authelia.zeroq.su" = {
+        forceSSL = true;
+        enableACME = true;
+        locations."/" = {
+          proxyPass = "http://127.0.0.1:9091";
+          proxyWebsockets = true;
+        };
+      };
       "pdf.private" = {
         forceSSL = false;
         enableACME = false;
@@ -281,18 +315,10 @@ in
     (xlib.helpers.mkTmpfile "d" "/var/lib/vtimeline" "0755" "nginx" "nginx")
   ];
 
-  # htpasswd file for vtimeline.zeroq.su basic auth.
+  # Note: the previous vtimeline-htpasswd sops declaration lived here. It
-  # Source layout (per modules/server/secrets/vtimeline-htpasswd.yaml):
+  # was removed when authelia replaced nginx's auth_basic (see the vtimeline
-  #   passwords: |
+  # vhost above). The encrypted file modules/server/secrets/vtimeline-htpasswd.yaml
-  #     <user>:<bcrypt-or-apr1-hash>
+  # itself was kept untouched per the repo policy of not modifying secrets
-  # sops-nix extracts the `passwords` key as the only decrypted content.
+  # without explicit owner sign-off; delete it with `sops --version` and
-  # The resulting file is consumed by nginx via auth_basic_user_file.
+  # `rm` once the cutover is verified.
-  sops.secrets.vtimeline-htpasswd = {
-    format = "yaml";
-    key = "passwords";
-    sopsFile = ./secrets/vtimeline-htpasswd.yaml;
-    owner = "nginx";
-    group = "nginx";
-    mode = "0640";
-  };
 }

modules/server/secrets/authelia.yaml

@@ -0,0 +1,19 @@
+jwt_secret: ENC[AES256_GCM,data:Sq3SR3GF2PKU/EmtosEIgkVBGx0ycQfYBy3SmNB46bflTX3HvjY7gXSXt13khLRNjYwqnLQ/VWnhSF7QmjO+QA==,iv:L1c/Tb1nb1JNY9FdU7SoZih9CdRO0sDErA+OBmCe1nY=,tag:aYS8NoMW1OqVT/q60nVU6A==,type:str]
+session_secret: ENC[AES256_GCM,data:gJnvSc8IvfJEemptMvq72Tiv6O19E63fSpzPtzKy4u1a9HdwUGJADz9nzQbLTqk5lP4OSQnKEgZyiDvCpFNE6A==,iv:oWG/ht5McEGqYXdls4BsDSLMF4G8lX957urZL3vlyxY=,tag:SoY4DvzdPrVftKOQQcgmfQ==,type:str]
+storage_encryption_key: ENC[AES256_GCM,data:1uoto0pqv1ahIxc00XzY+X0I0Eb3po/FPWOsmyFlcOhtpzK3od0+4a2jL8PicqbIf6F0hNp1gYUc11ofO7Mj1g==,iv:IFw4Y/cL3Hqa0fIPeKhN3SdrlOLFFJiJLe1MTNue+gk=,tag:eSAFNxpkaYWkyFVoWzSuMA==,type:str]
+users_database: ENC[AES256_GCM,data:KCbWYaXNk33ybfYrE7oJPREBLSQDlQfdzxzbCqYTX4ZTjb3R3yRPzRCqLzjy3UP165q5MjOcsXmluJ4U0Apd8+sKJj5+XkEL3GMIhxExB2JpVjriyObX4iayuoUlYXD7JVTBVVIZIfXWH5ySTbLw35sN0LmbBaRPSE5YNliOtUe91W82nbifP3qYvOaYFYFe5MaBLc2XpaWJcv+Gio3iQ5X5mYhTgwNMlCZK5/KqlS3oNQswkuvSuzWNG3+/ev+Byt8KY6ec/bnM74ebTs7obJK3,iv:mEFmiDdzw+s7jusN4GggZ7FO5C2IUUKGAJ8PIBMC/KY=,tag:MwlfPGs3egq0B4RxfAQ+Jw==,type:str]
+sops:
+    age:
+        - enc: |
+            -----BEGIN AGE ENCRYPTED FILE-----
+            YWdlLWVuY3J5cHRpb24ub3JnL3YxCi0+IFgyNTUxOSBhYjh3WjVTN2JXdjJXYXY3
+            UnhveDN2WkxsRThQWVhpTlBHL0FiSEF4dVZRCnRrQlZiM3hxU0FzUHM3YVpkOXpF
+            alowVnpENWUzdzRYQ1R5cW5CVDVEcTQKLS0tIDU1MFJCQUFIdUoyWHBQSkwweUMv
+            SFhPQmFOdmY5QUpLVUdpUGRWL25aTE0K5BL3mIZI6Wl4TZIKQPUJ7PxvrNe+1t+S
+            ra8EJtInXy4HeNWye9sdR3BHD7QWYT46RAHBSdn+4SxtV6LOHiXBgg==
+            -----END AGE ENCRYPTED FILE-----
+          recipient: age13l2gtk0nzr484zprp7e0pkrt0ne0j4asyn2pjmlaw73nte7t7d8q4sqtxm
+    lastmodified: "2026-10-08T00:38:38Z"
+    mac: ENC[AES256_GCM,data:EERhYt8a9ElV9RvcvqcM7lxLE9lwx0juW9RQgZD1rNaLs8wx+/1hTt7HmVRyiuFwMOmmL3lrwxC7cBV7GUkF6hbnWz+tuDO1EXBq3ooN/KIikFnjia6A95TinZzRKYmv3K/CdISGu5yGpZ9bVSqaq0YdB0MB32e6Q0iEXVxda4o=,iv:UZxgFjGs6FqavbTk4XYAs1MmCLgV3JktOrmVcy/nM3Q=,tag:EP7z+S1vyRSn8vchc0tgRw==,type:str]
+    unencrypted_suffix: _unencrypted
+    version: 3.13.3