Correctly detect current Cloudflare IPs

[pkoenig10]

When using the Cloudflare DNS provider, the current IPs are not detected correctly.

found DNS record    {"type": "A", "name": "", "zone": "example.com", "value": "12.34.56.78"}
found DNS record    {"type": "AAAA", "name": "", "zone": "example.com", "value": "2001:db8:3333:4444:5555:6666:7777:8888"}
domain not found in DNS {"domain": "example.com"}
domain not found in DNS {"domain": "example.com"}
looked up current IPs from DNS  {"lastIPs": {"example.com":{"A":[""],"AAAA":[""]}}}

The name in the Caddy config is @, but the name in the returned Record is the empty string. So we insert into recMap using .example.com, but lookup using example.com.

The libdns documentation isn't clear on the expected behavior of Record.Name for A records. If the empty string is a valid value for A records, then this PR is the correct fix. But if the value for A records should always be @, then this should be fixed in libdns/cloudflare.

I assume this is the correct fix since it matches similar code in libdns.

[mholt]

Ah, thanks for this. I haven't given the empty string / self case much consideration yet. Some DNS providers expect/require a @ whereas others use empty string. We should probably figure out which convention is best for libdns to use and go with that.

Do you have a preference/opinion/thoughts on whether @ or "" should be used?

[francislavoie]

Maybe we should call libdns.AbsoluteName() in here and then TrimSuffix the ., I dunno.

[pkoenig10]

I don't have a strong opinion. If it was up to me, I'd probably just use the empty string, for couple reasons:

• it feels less magic - @ isn't part of the DNS record, it's just a convention that some providers/clients use)
• CNAME records can't use the empty string - so there's no risk of ambiguity.

Whatever we decide, the value in the Caddy config should probably match the behavior of libdns. So if we change to use the empty string, this has the potential to break existing configurations which use @.

It also feels reasonable to me to just accept both values, like libdns.AbsoluteName.

[pkoenig10]

Maybe we should call libdns.AbsoluteName() in here and then TrimSuffix the .

This sounds reasonable to me.

[mholt]

Awesome. Thank you both!!