Lambda函数的URL报CORS错误，应该如何设置

Question

【以下的问题经过翻译处理】在使用Lambda函数URL代替API网关进行测试时，浏览器一直报CORS错误。在API网关上启用CORS，浏览器报错消失了。

$ curl -v https://lo1mb5fn4f.execute-api.ap-southeast-2.amazonaws.com/prod/default -X OPTIONS
*   Trying 52.62.9.26:443...
* Connected to lo1mb5fn4f.execute-api.ap-southeast-2.amazonaws.com (52.62.9.26) port 443 (#0)
* schannel: disabled automatic use of client certificate
* schannel: ALPN, offering http/1.1
* schannel: ALPN, server accepted to use http/1.1
> OPTIONS /prod/default HTTP/1.1
> Host: lo1mb5fn4f.execute-api.ap-southeast-2.amazonaws.com
> User-Agent: curl/7.79.1
> Accept: */*
>
* Mark bundle as not supporting multiuse
< HTTP/1.1 200 OK
< Date: Wed, 27 Apr 2022 09:18:52 GMT
< Content-Type: application/json
< Content-Length: 0
< Connection: keep-alive
< x-amzn-RequestId: 2b81917b-42e6-47ac-88dd-4211fb0b93ad
< Access-Control-Allow-Origin: *
< Access-Control-Allow-Headers: Content-Type,Authorization,X-Amz-Date,X-Api-Key,X-Amz-Security-Token
< x-amz-apigw-id: RO6ThFTYSwMFdqg=
< Access-Control-Allow-Methods: DELETE,GET,HEAD,OPTIONS,PATCH,POST,PUT
<
* Connection #0 to host lo1mb5fn4f.execute-api.ap-southeast-2.amazonaws.com left intact

然后在控制台中启用了CORS并对Lambda函数URL执行了相同的查询，但是没有返回CORS标头。

$ curl -v https://b3cdmthu62o6bqzcrb7efnw7be0ktquf.lambda-url.ap-southeast-2.on.aws/ -X OPTIONS
*   Trying 54.66.8.158:443...
* Connected to b3cdmthu62o6bqzcrb7efnw7be0ktquf.lambda-url.ap-southeast-2.on.aws (54.66.8.158) port 443 (#0)
* schannel: disabled automatic use of client certificate
* schannel: ALPN, offering http/1.1
* schannel: ALPN, server accepted to use http/1.1
> OPTIONS / HTTP/1.1
> Host: b3cdmthu62o6bqzcrb7efnw7be0ktquf.lambda-url.ap-southeast-2.on.aws
> User-Agent: curl/7.79.1
> Accept: */*
>
* Mark bundle as not supporting multiuse
< HTTP/1.1 200 OK
< Date: Wed, 27 Apr 2022 09:20:18 GMT
< Content-Type: application/json
< Content-Length: 20
< Connection: keep-alive
< x-amzn-RequestId: 13433ad6-7504-4054-abf5-ca53f9b39b3f
< X-Amzn-Trace-Id: root=1-62690ad2-0796999b639d9a5507c42dfb;sampled=0
<
"Hello from Lambda!"* Connection #0 to host b3cdmthu62o6bqzcrb7efnw7be0ktquf.lambda-url.ap-southeast-2.on.aws left intact

这似乎是Lambda读取CORS数据的一个错误，是否有一种方法可以将其升级到AWS并报告这是一个错误？

Answer

【以下的回答经过翻译处理】当你使用OPTIONS发送[Preflight Request](https://developer.mozilla.org/en-US/docs/Glossary/Preflight_request)时，你需要包括你来自的Origin和要检查允许的Request Method。你可以通过包括`Origin`和`Access-Control-Request-Method`头来实现。尝试使用以下curl命令，询问Lambda Function URL是否可以使用HTTP请求方法`DELETE`从`http://example.com`进行跨源请求： ``` curl --location --request OPTIONS '' \ --header 'Origin: http://example.com' \ --header 'Access-Control-Request-Method: DELETE' -v ``` 这与你指定的相同的CORS配置在我的测试Function URL中的响应是： ``` > OPTIONS / HTTP/1.1 > Host: > User-Agent: curl/7.64.1 > Accept: */* > Origin: http://example.com > Access-Control-Request-Method: DELETE > < HTTP/1.1 200 OK < Date: Wed, 27 Apr 2022 14:50:31 GMT < Content-Type: application/json < Content-Length: 0 < Connection: keep-alive < x-amzn-RequestId: fd7d31ab-604a-4cd0-9bae-ad9d83a74450 < Access-Control-Allow-Origin: * < Access-Control-Allow-Headers: content-type,authorization,x-amz-date,x-api-key,x-amz-security-token < Access-Control-Allow-Methods: GET,HEAD,POST,PUT,DELETE,PATCH ```

Lambda函数的URL报CORS错误，应该如何设置

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