nginx: Use openresty package. Add openidc plugin.

hosts/architect/nginx.nix

@@ -1,8 +1,9 @@
-{ services, ... }:
+{ services, pkgs, lib, ... }:
 
 {
   services.nginx = {
     enable = true;
+    package = pkgs.openresty;
     recommendedGzipSettings = true;
     recommendedOptimisation = true;
     recommendedProxySettings = true;
@@ -25,6 +26,17 @@
         "/wat.jpg" = { };
       };
     };
+    appendHttpConfig = let
+      extraPureLuaPackages = with pkgs.luajitPackages; [ lua-resty-openidc ];
+      luaPath = pkg: "${pkg}/share/lua/5.1/?.lua";
+      makeLuaPath = lib.concatMapStringsSep ";" luaPath;
+    in ''
+      lua_package_path '${makeLuaPath extraPureLuaPackages};;';
+
+      # cache for OIDC discovery metadata
+      lua_shared_dict discovery 1m;
+    '';
+
     appendConfig = ''
       worker_processes 24;
     '';