javascript - 无法通过 CORS 访问部分视频内容到亚马逊 EC2

Question

为此，我已尽力使用 stackoverflow 上已有的答案，但自 2 天以来一直没有成功。我想要做的是访问存储在亚马逊 Ec2 实例中的 Mp4 视频。这导致

XMLHttpRequest 无法加载请求的资源上不存在“Access-Control-Allow-Origin”标头。因此不允许访问源“ http://localhost:8080 ”。响应具有 HTTP 状态代码 405。

我的 ngnix.conf 有像这样的标题

http{
       ............
        server{
                location / {
                        if ($request_method = 'OPTIONS') {
                                add_header 'Access-Control-Allow-Origin' '*';
                                add_header 'Access-Control-Allow-Credentials' 'true';
                                add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS';
                                add_header 'Access-Control-Allow-Headers' 'DNT,X-CustomHeader,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type';
                                add_header 'Access-Control-Max-Age' 1728000;
                                add_header 'Content-Type' 'text/plain charset=UTF-8';
                                add_header 'Content-Length' 0;
                                return 204;
                        }
                        if ($request_method = 'POST') {
                                add_header 'Access-Control-Allow-Origin' '*';
                                add_header 'Access-Control-Allow-Credentials' 'true';
                                add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS';
                                add_header 'Access-Control-Allow-Headers' 'DNT,X-CustomHeader,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type';
                        }
                        if ($request_method = 'GET') {
                                add_header 'Access-Control-Allow-Origin' '*';
                                add_header 'Access-Control-Allow-Credentials' 'true';
                                add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS';
                                add_header 'Access-Control-Allow-Headers' 'DNT,X-CustomHeader,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type';
                        }
               }
       }


}

我的客户端 javascript 代码很简单，如下所示：

var createCORSRequest = function(method, url) {
      var xhr = new XMLHttpRequest();
      if ("withCredentials" in xhr) {
        // Most browsers.
        xhr.open(method, url, true);

        xhr.setRequestHeader('Access-Control-Allow-Methods', "HEAD, GET, POST, PUT, DELETE, OPTIONS");
        xhr.setRequestHeader('Content-type', 'text/plain');
        xhr.setRequestHeader('Access-Control-Allow-Origin', '*');
      }  else {
        // CORS not supported.
        xhr = null;
      }
      return xhr;
    };

    var url = <videoURL> ;
    var method = 'GET';
    var xhr = createCORSRequest(method, url);

    xhr.onload = function() {
      // Success code goes here.
    };

    xhr.onerror = function() {
      // Error code goes here.
    };

    xhr.send();