Extra leading character in TXT records about lua-resty-dns

[holic]

I should note that in all of these cases, dig returns the correct record value.

[agentzh]

@holic Do you have a live DNS record in the wild that I can check out? Failing that, will you provide a hex dump of the raw response UDP packet payload from your DNS server?

[holic]

@agentzh Sure! Try dig TXT github.keviningersoll.com.

[agentzh]

@holic Okay, I see what is going on. This is because the current implementation of resty.dns.resolver does not parse the TXT record data into one or more "character-strings". I'll fix it shortly. The weird prefix characters you're seeing are just the length octets for the following strings. Thank you for your report!

[agentzh]

@holic I've just committed a fix to git master. Will you try it out?

[holic]

@agentzh Can you explain the table of strings? In what cases would the strings be separated and why? I would expect a TXT record to have a single string value.

[agentzh]

@holic RFC 1035 allows multiple character strings sit inside a single TXT record data part: http://tools.ietf.org/html/rfc1035#section-3.3.14 I just implement it the way the standard specifies.

Whether or not to make use of multiple strings is completely depending on the concrete application-level decisions. In the real world, it is usually just a single string though.

[holic]

Ahh, I didn't realize that TXT records could include separate "parts".

For anyone looking at this issue later, most TXT records you'll find look like this:

some.host.name. IN TXT "some-txt=some value"

Above is an example of a single string value. This is also a perfectly valid TXT record:

some.host.name. IN TXT "some-txt=some value" "another-txt=another value"

Above is an example of multiple string values.