cors-midd

+const _ = require('lodash');
+
+/**
+ * 异步请求跨域处理
+ */
+module.exports = (req, res, next) => {
+    let allowOrigin = _.get(req, 'headers.origin', null) ?
+        req.headers.origin : req.protocol + '://' + req.headers.host;
+
+    res.setHeader('Access-Control-Allow-Origin', allowOrigin);
+    res.setHeader('Access-Control-Allow-Credentials', 'true');
+
+    return next();
+};