将跨源资源共享 (CORS) 标头添加到响应 - Amazon CloudFront

将跨源资源共享 (CORS) 标头添加到响应

以下查看器响应函数在响应未包含 Access-Control-Allow-Origin HTTP 标头时，将此标头添加到响应中。此标头属于跨源资源共享 (CORS) 的一部分。该标头的值 (*) 告诉 Web 浏览器允许来自任何源的代码访问此资源。有关更多信息，请参阅 MDN Web Docs 网站上的 Access-Control-Allow-Origin。

在 GitHub 上查看此示例。

JavaScript runtime 2.0
async function handler(event)  {
    const request = event.request;
    const response  = event.response;
 
    // If Access-Control-Allow-Origin CORS header is missing, add it.
    // Since JavaScript doesn't allow for hyphens in variable names, we use the dict["key"] notation.
    if (!response.headers['access-control-allow-origin'] && request.headers['origin']) {
        response.headers['access-control-allow-origin'] = {value: request.headers['origin'].value};
        console.log("Access-Control-Allow-Origin was missing, adding it now.");
    }

    return response;
}
JavaScript runtime 1.0
function handler(event)  {
    var response  = event.response;
    var headers  = response.headers;

    // If Access-Control-Allow-Origin CORS header is missing, add it.
    // Since JavaScript doesn't allow for hyphens in variable names, we use the dict["key"] notation.
    if (!headers['access-control-allow-origin']) {
        headers['access-control-allow-origin'] = {value: "*"};
        console.log("Access-Control-Allow-Origin was missing, adding it now.");
    }

    return response;
}