vue2.js 解决跨域问题

const path = require('path');

function resolve(dir) {
    return path.join(__dirname, dir)
}
module.exports = {
    pages: {
        index: {
            entry: 'src/main.js'
        }
    },
    productionSourceMap: false,// 生产环境是否要生成 sourceMap
    publicPath: './',  //   部署应用包时的基本 URL
    outputDir: 'dist',  //   打包时输出的文件目录
    assetsDir: 'assets',  //   放置静态文件夹目录
    devServer: {
        port: 8001, //开发环境运行时的端口
        https: false,//是否启用HTTPS协议
        open: true, //项目运行成功后是否直接打开浏览器
        hot: true,//是否开启热加载
        overlay: true, //当出现编译错误或警告时，在浏览器中显示全屏覆盖。
        proxy: {   //服务器代理
            '/api': {
                target: "http://39.107.251.252:8001",   // 实际跨域请求的API地址
                secure: false,   // https请求则使用true
                ws: true,
                changeOrigin: true,  // 跨域
        // 请求地址重写  http://front-end/api/login ⇒ http://api-url/login
                pathRewrite: {
                    '^/api': '/',
                }

            }
        },// dev环境下，webpack-dev-server 相关配置
        lintOnSave: false,//是否在开发环境下每次保存代码时都启用 eslint验证
        css: {},// css的处理
    //vue-cli内部的webpack配置
        chainWebpack(config) {
      // it can improve the speed of the first screen, it is recommended to turn on preload
            config.plugin('preload').tap(() => [
                {
                    rel: 'preload',
          // to ignore runtime.js
          // https://github.com/vuejs/vue-cli/blob/dev/packages/@vue/cli-service/lib/config/app.js#L171
                    fileBlacklist: [/\.map$/, /hot-update\.js$/, /runtime\..*\.js$/],
                    include: 'initial'
                }
            ])

      // when there are many pages, it will cause too many meaningless requests
            config.plugins.delete('prefetch')

      // set svg-sprite-loader
            config.module
        .rule('svg')
        .exclude.add(resolve('src/icons'))
        .end()
            config.module
        .rule('icons')
        .test(/\.svg$/)
        .include.add(resolve('src/icons'))
        .end()
        .use('svg-sprite-loader')
        .loader('svg-sprite-loader')
        .options({
    symbolId: 'icon-[name]'
})
        .end()

            config.module
        .rule('markdown')
        .test(/\.md$/)
        .use('frontmatter-markdown-loader')
        .loader('frontmatter-markdown-loader')
        .tap(() => {
    return {
        mode: [require('frontmatter-markdown-loader/mode').VUE_COMPONENT],
        vue: {
            root: 'markdown-body'
        }
    }
})
            config
        .when(process.env.NODE_ENV !== 'development',
          config => {
    config
              .plugin('ScriptExtHtmlWebpackPlugin')
              .after('html')
              .use('script-ext-html-webpack-plugin', [{
                // `runtime` must same as runtimeChunk name. default is `runtime`
    inline: /runtime\..*\.js$/
}])
              .end()
    config
              .optimization.splitChunks({
    chunks: 'all',
    cacheGroups: {
        libs: {
            name: 'chunk-libs',
            test: /[\\/]node_modules[\\/]/,
            priority: 10,
            chunks: 'initial' // only package third parties that are initially dependent
        },
        elementUI: {
            name: 'chunk-elementUI', // split elementUI into a single package
            priority: 20, // the weight needs to be larger than libs and app or it will be packaged into libs or app
            test: /[\\/]node_modules[\\/]_?element-ui(.*)/ // in order to adapt to cnpm
        },
        commons: {
            name: 'chunk-commons',
            test: resolve('src/components'), // can customize your rules
            minChunks: 3, //  minimum common number
            priority: 5,
            reuseExistingChunk: true
        }
    }
})
            // https:// webpack.js.org/configuration/optimization/#optimizationruntimechunk
    config.optimization.runtimeChunk('single')
}
        )
        },
        pluginOptions: {}, // 可以用来传递任何第三方插件选项
    }
}