optimize directory structure

lib/middleware/header.js

@@ -0,0 +1,15 @@
+const logger = require('../utils/logger');
+const config = require('../config');
+const headers = {
+    'Access-Control-Allow-Origin': '*',
+    'Access-Control-Allow-Headers': 'Content-Type, Content-Length, Authorization, Accept, X-Requested-With , yourHeaderFeild',
+    'Access-Control-Allow-Methods': 'PUT, POST, GET, DELETE, OPTIONS',
+    'Content-Type': 'application/xml; charset=utf-8',
+    'Cache-Control': `max-age=${config.cacheExpire / 2}`,
+};
+
+module.exports = async (ctx, next) => {
+    logger.info(`${ctx.url}, user IP: ${ctx.ips[0] || ctx.ip}`);
+    ctx.set(headers);
+    await next();
+};