nginx: centralize configuration

services/nginx.nix

@@ -0,0 +1,21 @@
+# Part of config shamelessly stolen from:
+#
+# https://github.com/delroth/infra.delroth.net
+{ config, lib, ... }:
+{
+  # Whenever something defines an nginx vhost, ensure that nginx defaults are
+  # properly set.
+  config = lib.mkIf ((builtins.attrNames config.services.nginx.virtualHosts) != [ ]) {
+    services.nginx = {
+      enable = true;
+      statusPage = true; # For monitoring scraping.
+
+      recommendedGzipSettings = true;
+      recommendedOptimisation = true;
+      recommendedTlsSettings = true;
+      recommendedProxySettings = true;
+    };
+
+    networking.firewall.allowedTCPPorts = [ 80 443 ];
+  };
+}