Update the configuration of WG_DEFAULT_ADDRESS and WG_POST_UP in the config.js file.

src/config.js

@@ -1,6 +1,13 @@
 'use strict';
 
 const { release } = require('./package.json');
+const WG_DEFAULT_ADDRESS = String(process.env.WG_DEFAULT_ADDRESS || '10.8.0.x').replace('x', '0');
+const WG_POST_UP = [
+  `iptables -t nat -A POSTROUTING -s ${WG_DEFAULT_ADDRESS}/24 -o eth0 -j MASQUERADE;`,
+  'iptables -A INPUT -p udp -m udp --dport 51820 -j ACCEPT;',
+  'iptables -A FORWARD -i wg0 -j ACCEPT;',
+  'iptables -A FORWARD -o wg0 -j ACCEPT;',
+].join(' ');
 
 module.exports.RELEASE = release;
 module.exports.PORT = process.env.PORT || 51821;
@@ -10,19 +17,12 @@ module.exports.WG_HOST = process.env.WG_HOST;
 module.exports.WG_PORT = process.env.WG_PORT || 51820;
 module.exports.WG_MTU = process.env.WG_MTU || null;
 module.exports.WG_PERSISTENT_KEEPALIVE = process.env.WG_PERSISTENT_KEEPALIVE || 0;
-module.exports.WG_DEFAULT_ADDRESS = process.env.WG_DEFAULT_ADDRESS || '10.8.0.x';
+module.exports.WG_DEFAULT_ADDRESS = WG_DEFAULT_ADDRESS;
 module.exports.WG_DEFAULT_DNS = typeof process.env.WG_DEFAULT_DNS === 'string'
   ? process.env.WG_DEFAULT_DNS
   : '1.1.1.1';
 module.exports.WG_ALLOWED_IPS = process.env.WG_ALLOWED_IPS || '0.0.0.0/0, ::/0';
-
 module.exports.WG_PRE_UP = process.env.WG_PRE_UP || '';
-module.exports.WG_POST_UP = process.env.WG_POST_UP || `
+module.exports.WG_POST_UP = process.env.WG_POST_UP || WG_POST_UP;
-iptables -t nat -A POSTROUTING -s ${module.exports.WG_DEFAULT_ADDRESS.replace('x', '0')}/24 -o eth0 -j MASQUERADE;
-iptables -A INPUT -p udp -m udp --dport 51820 -j ACCEPT;
-iptables -A FORWARD -i wg0 -j ACCEPT;
-iptables -A FORWARD -o wg0 -j ACCEPT;
-`.split('\n').join(' ');
-
 module.exports.WG_PRE_DOWN = process.env.WG_PRE_DOWN || '';
 module.exports.WG_POST_DOWN = process.env.WG_POST_DOWN || '';