我无法在Django API中解决CORS问题。当我调用这个API时，我得到错误:

CORS策略阻止了在“http://localhost:8000/”处从源“http://localhost'提取数据的访问:对预飞行请求的响应未通过访问控制检查:请求的资源上不存在”Access-Control-Allow-Origin“标头。如果不透明响应满足您的需要，请将请求的模式设置为“no-cors”，以便在禁用CORS的情况下获取资源。

为了启用CORS，我做了pip安装django-cors-headers，并将以下代码添加到settings.py:

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'corsheaders',
]

MIDDLEWARE_CLASSES = [
    'corsheaders.middleware.CorsMiddleware',
    'django.middleware.common.CommonMiddleware',
    'django.middleware.security.SecurityMiddleware',
    'django.contrib.sessions.middleware.SessionMiddleware',
    'django.middleware.common.CommonMiddleware',
    'django.middleware.csrf.CsrfViewMiddleware',
    'django.contrib.auth.middleware.AuthenticationMiddleware',
    'django.contrib.auth.middleware.SessionAuthenticationMiddleware',
    'django.contrib.messages.middleware.MessageMiddleware',
    'django.middleware.clickjacking.XFrameOptionsMiddleware',
]

CORS_ORIGIN_WHITELIST = [
    'localhost:80',
    'localhost:8000',
    '127.0.0.1:8000'
]

我应该说我在Docker上运行我的项目。这是docker-compose.yml:

version: '2'

services:
  django-docker:
    build:
      context: .
      dockerfile: Dockerfile.django
    container_name: my.django
    image: my-django
    ports:
      - 8000:8000

  webapp-docker:
    build:
      context: .
      dockerfile: Dockerfile.webapp
    container_name: my.webapp
    image: my-web
    ports:
      - 80:80