Allow the frontend to remove caching on some API requests

arkindex/project/settings.py

@@ -13,6 +13,7 @@ https://docs.djangoproject.com/en/1.11/ref/settings/
 import os
 import sys
 import logging
+from corsheaders.defaults import default_headers
 
 
 def env2list(env_name, separator=',', default=[]):
@@ -392,6 +393,9 @@ CORS_ORIGIN_WHITELIST = env2list('CORS_ORIGIN_WHITELIST', default=[
     '127.0.0.1:5000',
 ])
 CORS_ALLOW_CREDENTIALS = True
+CORS_ALLOW_HEADERS = default_headers + (
+    'cache-control',  # Allow the frontend to prevent caching some API requests
+)
 CORS_URLS_REGEX = r'^/(api|ponos)/.*$'
 
 # Docker images used by our ponos workflow