Nginx 配置反向代理 add_header 不生效的原因及解决办法 作者: Chuwen 时间: 2021-04-30 分类: Nginx ## 背景 因同事用 Hyperf 搭建的接口，然后用 Vue.js 写的前端去调用，出现跨域问题 ## 无效原因 > Nginx `add_header` 只对 `200,201,204,206,301,302,303,304,307` 这些状态码生效，对于 401 405 403 这些状态码是不生效的。 恰好我测试的时候就随便访问了个链接，返回的状态码是 **404** 的，结果一直刷新都不出来添加的 `header` ## 解决办法 在末尾加一个 `always` 即可，即： ```conf add_header Access-Control-Allow-Origin * always; ``` 此外还引出一个问题，就是如果你将 **Access-Control-Allow-Origin** 头的值设置为 `*`，那么前端进行请求时，不出意外的话浏览器控制台就会提示这个错误：  > Access to XMLHttpRequest at 'http://api.xxxxxxx.com/v1/userinfo from origin 'http://localhost:8080' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: The value of the 'Access-Control-Allow-Origin' header in the response must not be the wildcard '*' when the request's credentials mode is 'include'. The credentials mode of requests initiated by the XMLHttpRequest is controlled by the withCredentials attribute. > > **机翻成中文：** > > 通过CORS策略已阻止从来源 “http://localhost:8080” 访问 “http://api.xxxxxxx.com/v1/userinfo” 处的XMLHttpRequest：对预检请求的响应未通过访问 控制检查：当请求的凭据模式为“包括”时，响应中“访问控制允许-来源”标头的值不得为通配符“ *”。 XMLHttpRequest 发起的请求的凭据模式由 withCredentials 属性控制。 > > 相关链接：https://developer.mozilla.org/zh-CN/docs/Web/HTTP/Headers/Access-Control-Allow-Credentials ### 原因是：当前端(如 axios)配置 `withCredentials=true` 时, 后端配置 `Access-Control-Allow-Origin` 不能为 `*`, 必须是相应地址 ### axios 设置 withCredentials 为 false ```js // axios配置 axios.defaults.withCredentials = false; // 携带cookie ``` --- 更多相关跨于问题，这篇文章可以作参考：https://juejin.cn/post/6844903748288905224 以下是从上述链接渣摘抄 ### 问题 1 > 解决方案：当前端配置withCredentials=true时, 后端配置Access-Control-Allow-Origin不能为*, 必须是相应地址 ``` Access to XMLHttpRequest at 'http://127.0.0.1:8081/getInfo?t=1545900042823' from origin 'http://localhost:8080' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: The value of the 'Access-Control-Allow-Origin' header in the response must not be the wildcard '*' when the request's credentials mode is 'include'. The credentials mode of requests initiated by the XMLHttpRequest is controlled by the withCredentials attribute. ``` ### 问题 2 > 解决方案：当配置withCredentials=true时, 后端需配置Access-Control-Allow-Credentials ``` Access to XMLHttpRequest at 'http://127.0.0.1:8081/getInfo?t=1545899934853' from origin 'http://localhost:8080' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: The value of the 'Access-Control-Allow-Credentials' header in the response is '' which must be 'true' when the request's credentials mode is 'include'. The credentials mode of requests initiated by the XMLHttpRequest is controlled by the withCredentials attribute. ``` ### 问题 3 > 解决方案：当前端配置请求头时, 后端需要配置Access-Control-Allow-Headers为对应的请求头集合 ``` Access to XMLHttpRequest at 'http://127.0.0.1:8081/getInfo?t=1545898876243' from origin 'http://localhost:8080' has been blocked by CORS policy: Request header field x-requested-with is not allowed by Access-Control-Allow-Headers in preflight response. ``` 标签: Nginx, 跨域