System/Servenix: Add initial servenix system configuration

system/services/authelia.nix

@@ -0,0 +1,31 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}: {
+  virtualisation.oci-containers.containers.authelia = {
+    image = "authelia/authelia:latest";
+    autoStart = true;
+
+    dependsOn = [
+      # "pihole"
+    ];
+
+    ports = [
+      # "9091:9091"
+    ];
+
+    volumes = [
+      "authelia_config:/config"
+    ];
+
+    environment = {
+      TZ = "Europe/Berlin";
+    };
+
+    extraOptions = [
+      "--net=behind-nginx"
+    ];
+  };
+}