1. 打开index.html
<!-- 引入JS -->
<script src="http://pv.sohu.com/cityjson?ie=utf-8"></script>
2. 获取IP
let IP = returnCitySN["cip"]；
localStorage.setItem('ip',IP);
完整代码：
<!DOCTYPE html>
<html lang="zh-CN">
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<title>
<%= htmlWebpackPlugin.options.title %>
</title>
...省略其他代码
<!-- 关键点1:引入JS -->
<script src="http://pv.sohu.com/cityjson?ie=utf-8"></script>
</head>
<body>
<noscript>
<strong>Please enable JavaScript to continue.</strong>
</noscript>
<div id="app"></div>
<!-- built files will be auto injected -->
<script>
//这里是关键点2: 获取用户真实IP地址（外网ip） 并存储在本地
// document.write(returnCitySN["cip"]+','+returnCitySN["cname"])
localStorage.setItem('ip',returnCitySN["cip"])
</script>
</body>
</html>