rest - 已被 CORS 策略 : Response to preflight request doesn’t pass access control check 阻止

Question

我已经创建了旅行服务器。它工作正常，我们可以通过 Insomnia 发出 POST 请求，但是当我们在前端通过 axios 发出 POST 请求时，它会发送错误:

has been blocked by CORS policy: Response to preflight request doesn’t pass access control check: It does not have HTTP ok status.

我们对 axios 的要求:

let config = {
headers: {
  "Content-Type": "application/json",
  'Access-Control-Allow-Origin': '*',
  }
}

let data = {
  "id": 4
 }

 axios.post('http://196.121.147.69:9777/twirp/route.FRoute/GetLists', data, config)
   .then((res) => {
      console.log(res)
     })
    .catch((err) => {
      console.log(err)
   });
} 

我的 go 文件:

func setupResponse(w *http.ResponseWriter, req *http.Request) {
    (*w).Header().Set("Access-Control-Allow-Origin", "*")
    (*w).Header().Set("Access-Control-Allow-Methods", "POST,GET,OPTIONS, PUT, DELETE")

    (*w).Header().Set("Access-Control-Allow-Headers", "Accept, Content-Type, Content-Length, Accept-Encoding, X-CSRF-Token, Authorization")
}


func WithUserAgent(base http.Handler) http.Handler {
    return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {

    ctx := r.Context()
    ua := r.Header.Get("Jwt")
    ctx = context.WithValue(ctx, "jwt", ua)

    r = r.WithContext(ctx)

    setupResponse(&w, r)
     base.ServeHTTP(w, r)
  })
}

const (
    host     = "localhost"
    port     = 5432
    user     = "postgres"
    password = "postgres"
    dbname   = "postgres"
)

func main() {

    psqlInfo := fmt.Sprintf("host=%s port=%d user=%s "+
           "password=%s dbname=%s sslmode=disable",
               host, port, user, password, dbname)

    server := &s.Server{psqlInfo}

    twirpHandler := p.NewFinanceServiceServer(server, nil)

    wrap := WithUserAgent(twirpHandler)
      log.Fatalln(http.ListenAndServe(":9707", wrap))
}

正如我之前在 Insomnia 上所说的，它工作得很好，但是当我们发出 axios POST 请求时，在浏览器的控制台上会出现以下内容:

has been blocked by CORS policy: Response to preflight request doesn’t pass access control check: It does not have HTTP ok status.

Answer 1

我相信这是最简单的例子:

header := w.Header()
header.Add("Access-Control-Allow-Origin", "*")
header.Add("Access-Control-Allow-Methods", "DELETE, POST, GET, OPTIONS")
header.Add("Access-Control-Allow-Headers", "Content-Type, Authorization, X-Requested-With")

您还可以为 Access-Control-Max-Age 添加 header ，当然您可以允许任何您希望的 header 和方法。

最后你要响应初始请求:

if r.Method == "OPTIONS" {
    w.WriteHeader(http.StatusOK)
    return
}

编辑(2019 年 6 月):我们现在使用 gorilla为了这。他们的东西得到了更积极的维护，而且他们已经这样做了很长时间。留下旧链接，以防万一。

下面的旧中间件推荐: 当然，为此使用中间件可能会更容易。我想我没用过，但是this one似乎强烈推荐。