Ceph storage engine only supports path-style bucket addressing currently. Quay should implement boto2 SubdomainCallingFormat in the storage/cloud.py to support virtual-hosted–style addressing.

Path-style URLs follow the format:

 https://s3.Region.amazonaws.com/bucket-name/keyname 

Virtual hosted style URLs follow the format shown:

 https://bucket-name.s3.Region.amazonaws.com/keyname

https://github.com/quay/quay/blob/master/storage/cloud.py#L706
http://boto.cloudhackers.com/en/latest/ref/s3.html#boto.s3.connection.SubdomainCallingFormat