Add Authelia configuration and secrets management

authelia.nix

@@ -0,0 +1,84 @@
+{ config, ... }:
+{
+  # Give authelia-main user access to its agenix secrets
+  age.secrets."authelia-jwt-secret" = {
+    file  = ./secrets/authelia-jwt-secret.age;
+    owner = "authelia-main";
+    group = "authelia-main";
+  };
+  age.secrets."authelia-storage-key" = {
+    file  = ./secrets/authelia-storage-key.age;
+    owner = "authelia-main";
+    group = "authelia-main";
+  };
+  age.secrets."authelia-session-secret" = {
+    file  = ./secrets/authelia-session-secret.age;
+    owner = "authelia-main";
+    group = "authelia-main";
+  };
+  age.secrets."authelia-users" = {
+    file  = ./secrets/authelia-users.age;
+    owner = "authelia-main";
+    group = "authelia-main";
+  };
+
+  services.authelia.instances.main = {
+    enable = true;
+
+    secrets = {
+      jwtSecretFile          = config.age.secrets."authelia-jwt-secret".path;
+      storageEncryptionKeyFile = config.age.secrets."authelia-storage-key".path;
+      sessionSecretFile      = config.age.secrets."authelia-session-secret".path;
+    };
+
+    settings = {
+      theme              = "auto";
+      default_2fa_method = "totp";
+
+      server.address = "tcp://127.0.0.1:9091";
+
+      log.level = "info";
+
+      totp = {
+        issuer = "srazka.com";
+        period = 30;
+      };
+
+      # File-based user database (simplest, no LDAP needed)
+      authentication_backend.file = {
+        path = config.age.secrets."authelia-users".path;
+        # Periodically re-reads the file; useful for adding users without restart
+        watch = true;
+      };
+
+      # SQLite is the simplest storage - fine for a single VPS
+      storage.local.path = "/var/lib/authelia-main/db.sqlite3";
+
+      # No email server needed for a homelab — disable email notifications
+      notifier.filesystem.filename = "/var/lib/authelia-main/notifications.txt";
+
+      session = {
+        expiration    = "1h";
+        inactivity    = "5m";
+        remember_me   = "1d";
+          
+        cookies = [
+          {
+            domain                = "srazka.com";
+            authelia_url          = "https://auth.srazka.com";
+            default_redirection_url = "https://hello.srazka.com";
+          }
+        ];
+      };
+
+      access_control = {
+        # Every request requires two-factor by default
+        default_policy = "two_factor";
+        # You can add per-domain rules here later, e.g.:
+        # rules = [
+        #   { domain = "hello.srazka.com"; policy = "two_factor"; }
+        # ];
+      };
+    };
+  };
+}