move caddy config into separate file

modules/services/caddy.nix

@@ -0,0 +1,26 @@
+{ config, pkgs, lib, ... }:
+
+let
+
+in {
+
+  options = {
+    caddyServers = lib.mkOption {
+      type = lib.types.attrs;
+      description = "Caddy JSON configs for http servers";
+    };
+  };
+
+  config = {
+
+    services.caddy = {
+      enable = true;
+      adapter = "''"; # Required to enable JSON
+      configFile = pkgs.writeText "Caddyfile"
+        (builtins.toJSON { apps.http.servers = config.caddyServers; });
+
+    };
+
+  };
+
+}

modules/services/calibre.nix

@@ -7,6 +7,8 @@ let
 
 in {
 
+  imports = [ ./caddy.nix ];
+
   options = {
     bookServer = lib.mkOption {
       type = lib.types.str;
@@ -26,12 +28,7 @@ in {
       };
     };
 
-    services.caddy = {
+    caddyServers.calibre = {
-      enable = true;
-      adapter = "''"; # Required to enable JSON
-      configFile = pkgs.writeText "Caddyfile" (builtins.toJSON {
-        apps.http.servers = {
-          calibre = {
       listen = [ ":443" ];
       routes = [{
         match = [{ host = [ config.bookServer ]; }];
@@ -42,10 +39,6 @@ in {
         }];
       }];
     };
-        };
-      });
-
-    };
 
     networking.firewall.interfaces.calibre = { allowedTCPPorts = [ 80 443 ]; };