I get a Sentry Error for an ALLOWED_HOSTS error from our Django app deployed on Fly.
DisallowedHost /
Invalid HTTP_HOST header: '146.70.54.85'. You may need to add '146.70.54.85' to ALLOWED_HOSTS.
How can I know which IPs to add to our Django allowed hosts? Is there some other setting I can use so instead of the IP address the health check uses a DNS entry (we already have *.fly.dev as allowed hosts)
Thanks!
Hi @shicholas ,
For our production we can start with .fly.dev (or the provider’s subdomain you chose) and update for the dedicated URL once your app is deployed to the hosting platform.
CSRF_TRUSTED_ORIGINS should also be defined with a list of origins to perform unsafe requests (e.g. POST). We can set the subdomain https://*.fly.dev (or the provider’s subdomain you chose) until our deployment is done and we have the proper domain for our website.
# settings.py
ALLOWED_HOSTS = ['localhost', '127.0.0.1', '.fly.dev'] # <-- Updated!
CSRF_TRUSTED_ORIGINS = ['https://*.fly.dev'] # <-- Updated!
I hope that helps,
Sergio Turpín
I have the same error. The IP reported as invalid host is the main public IPv4 attached to my machines.
I don’t understand why this may be used to access my app. I don’t even understand how a request to that host could be routed to the wsgi process (as far as I know, this IP is shared…).
At some point, I thought these requests were some sort of probe designed to check if a machine is alive or not. But these requests came at totally random moments.
So I have no clue on which source perfome these calls. I am open to any suggestion 
I see this error nightly, though not at a regular time, and from a different client IP each night. I’m very curious where it’s coming from!
I can’t trigger it on my own by going to https://66.241.125.126/ (my app’s IP), as Fly’s proxy is terminating TLS and rejecting the request before it hits my app.
It’s not the health check, as that’s running every 60s, and configured to a different Host header and path.
Here’s a sample of the request headers reported by Sentry:
