Invalid HTTP_HOST header: 'micromasters-rc.herokuapp.com'. You may need to add 'micromasters-rc.herokuapp.com' to ALLOWED_HOSTS.

[Ardiea]

https://mit-office-of-digital-learning.sentry.io/issues/4008009877/events/cca2d569874445d5b94089b091f14847/?project=104497&referrer=previous-event

nlevesque This is a fairly minor thing to fix, but it's definitely adding to alert noise. This error sort of looks like cloudfront is requesting robots.txt on the heroku subdomain for the app, which isn't in ALLOWED_HOSTS so it's logging this error. I don't think adding that host to ALLOWED_HOSTS is correct, nor would be adding a redirect to nginx since this appears to only be effecting RC. I'm assuming maybe there's some weird config somewhere since it only seems to be for robots.txt.