<link rel="stylesheet" href="https://unpkg.COM/element-ui/lib/theme-chalk/index.css" rel="external nofollow" >
    <script src="https://cdn.bootcss.com/vue/2.6.11/vue.min.js"></script>
    <script src="https://unpkg.com/element-ui/lib/index.js"></script>
    <script src="https://cdn.bootcss.com/vuex/3.0.1/vuex.min.js"></script>
    <script src="https://cdn.bootcss.com/vue-router/3.0.1/vue-router.min.js"></script>
    <script src="https://cdn.bootcss.com/axios/0.19.2/axios.min.js"></script>

    //cdn引入
    configureWebpack: {
        externals: {
            'vue': 'Vue',
            'element-ui': 'ELEMENT',
            'vue-router': 'VueRouter',
            'vuex': 'Vuex',
            'axios': 'axios'
        }
    }

 configureWebpack: config => {
        return {
            //配置cdn
            externals: {
                'vue': 'Vue',
                'element-ui': 'ELEMENT',
                'vue-router': 'VueRouter',
                'vuex': 'Vuex',
                'axios': 'axios'
            },
            //配置gzip压缩
            plugins: [
                new ComPressionWebpackPlugin({

                    test: new RegExp('\.(js|css)$'),
                    threshold: 10240,
                    minRatio: 0.8
                })
            ],
        }
    }

//配置GZIP压缩模块
const comPRession = require('compression');
//在所有中间件之前引入
app.use(compression());