将 AWS Amplify 前端连接到 AWS Elastic Beanstalk 后端时的 CORS 问题

Question

Background: I have the frontend (Vue) of my app deployed on AWS Amplify and the Backend (Python) on AWS Elastic Beanstalk. My frontend is connected to the backend via Axios.

Problem: When sending data from the front end to the backend, I get a CORS error Access to XMLHttpRequest at '***' from origin '***' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource.

When my frontend is sending data to the localhost, there's no issue, so I don't think it's an issue with my code. Is there something about the Elastic Beanstalk configuration I need to change?

I'm not sure what all code I need to include to get a proper answer, so please let me know what you'd like to see and I can update the question appropriately. I've added my application.py code below and am using Flask-CORS currently.

from flask import Flask, render_template
from flask import request, session
from flask_cors import CORS
import os
from common.api import api
from journal_blueprint import journal_blueprint
from manuscript_blueprint import manuscript_blueprint
from user_blueprint import user_blueprint
from models.decorators import requires_login
from models.user import User
from models.manuscript import Manuscript
from models.journal import Journal
from config_file import BaseConfig

application=Flask(__name__)

application.secret_key = BaseConfig.SECRET_KEY
application.config['SQLALCHEMY_DATABASE_URI'] = os.environ["DATABASE_URL"]

CORS(application)

application.register_blueprint(journal_blueprint, url_prefix='/journal')
application.register_blueprint(user_blueprint, url_prefix='/user')
application.register_blueprint(manuscript_blueprint, url_prefix='/manuscript')
application.register_blueprint(api, url_prefix="/api")


@application.route('/')
def home_template():
    return render_template('index.html')


@application.route('/login')
def login_template():
    return render_template('user/login.html')


@application.route('/register')
def register_template():
    return render_template('user/register.html')


if __name__ == '__main__':
    # application.run(debug=True)
    application.run()

Answer 1

Your configuration looks fine. Please look for errors in the elasticbeantalk logs. It is possible that the application throws some errors in the elasticbeanstalk environment, during which the CORS headers are not returned.