PTR Records could point to IP addresses

[nkallergis]

Environment

• Nautobot version: N/A
• nautobot-dns-models version: N/A

Proposed Functionality

Even though technically this might not be correct, a PTR record practically is bound to an IP address and defines the value of the reverse resolution (e.g. 192.0.2.1 --> srv01.example.com). Creating a Foreign Key from the PTRRecordModel to IPAddress would make this representation much easier. The ptrdname attribute can easily be calculated from the IP address using netutils like this:

from netutils.ip import ipaddress_address
ptrdname = ipaddress_address(ip.host, "reverse_pointer")

Use Case

Right now, there's no easy way to go from a PTR record to its respective IP address. Implementing the above would make this much easier, like with A/AAAA records. I believe it will also facilitate the enforcement of uniqueness - a given IP address within a given DNS Zone should only have one PTR record.