[Ci-users] Unable to access ci.centos.org from within Duffy

I'm trying to write a job which reads from:

https://ci.centos.org/artifacts/sig-atomic/rdgo/centos-continuous/

However on the Duffy node:

# host ci.centos.org
ci.centos.org has address 172.19.0.13
# 

Which appears to be something entirely different, it's a Jetty server (Server: Jetty(winstone-2.9)).

I tried working around this by using the public IP:

```
curl http://66.187.224.197/artifacts/sig-atomic/rdgo/centos-continuous/build/repodata/
```

But that just times out.

I can likely work around this by using rsync or some other way to get
content from artifacts, but it'd be really a lot better if I could read them over HTTP.