AWS API Gateway CORS Configuration optimization guide with Lambda Proxy Integration
I'm having a hard time understanding I've searched everywhere and can't find a clear answer... I'm having trouble getting CORS to work for my AWS API Gateway setup that uses Lambda proxy integration. I have set up my API Gateway to integrate with a Lambda function, and my function is returning JSON responses. However, when I make a cross-origin request from my frontend application, I receive a 'No 'Access-Control-Allow-Origin' header is present on the requested resource.' behavior in the browser console. I have already tried the following: 1. Enabled CORS in the API Gateway console for my resource. 2. Added the necessary headers in my Lambda function's response. Here’s a snippet of the relevant part of my Lambda function: ```python import json def lambda_handler(event, context): response = { 'statusCode': 200, 'headers': { 'Content-Type': 'application/json', 'Access-Control-Allow-Origin': '*', 'Access-Control-Allow-Headers': 'Content-Type', 'Access-Control-Allow-Methods': 'OPTIONS,POST,GET', }, 'body': json.dumps({'message': 'Hello from Lambda!'}) } return response ``` I’ve made sure to deploy my API after making changes, and I also tested using both Postman and my frontend app, but the CORS scenario continues. Additionally, I've confirmed that the OPTIONS method is enabled for my API Gateway resource, but it seems that the preflight request is still failing. Any suggestions on what I might be missing or how to troubleshoot this scenario further? Is there a better approach? For context: I'm using Python on Ubuntu. I'd really appreciate any guidance on this.