Bind news app to localhost for reverse proxy

web/server.js

@@ -6,6 +6,7 @@ const { URL } = require('url');
 const { Pool } = require('pg');
 
 const PORT = Number(process.env.APP_PORT || 3000);
+const HOST = process.env.APP_HOST || '0.0.0.0';
 const PUBLIC_DIR = path.join(__dirname, 'public');
 const ADMIN_TOKEN = process.env.APP_ADMIN_TOKEN || '';
 
@@ -306,7 +307,7 @@ const server = http.createServer(async (req, res) => {
   }
 });
 
-server.listen(PORT, '0.0.0.0', () => {
+server.listen(PORT, HOST, () => {
   console.log(`Daily news digest web listening on ${PORT}`);
 });