Request Host Not Whitelisted When Running Flask



When running my flask app locally with --host --port 8080 app.yaml I’m getting a message that the request host is not whitelist enabled for that server. I am able to get it running by setting --enable_host_checking to false but I don’t understand what I’m exactly doing with that flag. I’d love to learn what this means and how to resolve the issue without setting the host checking flag to false. Thanks!

Messages after running flask below without the flag set to false:

INFO     2018-02-01 18:22:37,893] Skipping SDK update check.
INFO     2018-02-01 18:22:38,069] Starting API server at: http://localhost:42895
WARNING  2018-02-01 18:22:38,069] Your python27 micro version is below 2.7.12, our current production version.
INFO     2018-02-01 18:22:38,082] Starting module "default" running at:
INFO     2018-02-01 18:22:38,083] Starting admin server at: http://localhost:8000
ERROR    2018-02-01 18:22:40,374] Request Host not whitelisted. Enabled hosts are set([''])