CORS 策略：请求 header 字段 access-control-allow-origin 在预检响应中被 Access-Control-Allow-Headers 不允许

Question

I use lambda as backend for AWS API Gateway with lambda proxy integration.

I have CORS enabled but is not working.

I receive this error:

Access to XMLHttpRequest at ' ' from origin ' ' has been blocked by CORS policy: Request header field access-control-allow-origin is not allowed by Access-Control-Allow-Headers in preflight response.

in serverless.yml:

resources:
  Resources:
GatewayResponseDefault4XX:
              Type: 'AWS::ApiGateway::GatewayResponse'
              Properties:
                ResponseParameters:
           gatewayresponse.header.Access-Control-Allow-Origin: "'*'"
           gatewayresponse.header.Access-Control-Allow-Headers: "'*'"
           gatewayresponse.header.Access-Control-Allow-Methods: "'GET,PUT,POST,DELETE,PATCH,OPTIONS'"
           gatewayresponse.header.Access-Control-Allow-Credentials: true
                ResponseType: DEFAULT_4XX
                RestApiId:
                  Ref: 'ApiGatewayRestApi' 

Answer 1

Can you please validate if your API Gateway configuration looks something like this on the console? You should see the Options endpoint if everything is setup correctly.

API Gateway Configuration