Pretty cool write up. It mentions that every host is running a DNS server that instances have access to, which is being utilized to store the public key (neat!)... is there any way for customers to consume this for other purposes, say out of the box service (instance) discovery?
Yes; the original purpose of private DNS at Fly was for service discovery. `your-app.internal` is the AAAA's of every instance for your-app; `nrt.your-app.internal` every instance in Japan, `aws-rds-1._peer.internal` is AAAA for the other side of a WireGuard gateway you created to bridge your apps to an RDS database, etc.