[dns-wg] Syntax of the "nserver:" Attribute in Domain Objects

Hi Anand,

Anand Buddhdev wrote:

> On 21/08/2012 10:28, Wilfried Woeber, UniVie/ACOnet wrote:
> 
> Hi Peter, Wilfried,
> 
> 
>>Well, I guess it takes Anand to describe the motivations for the changes,
>>but from a SW point of view, it might be a tad more "beautiful" to move
>>away from lists in the tag:value pairs. this *might* make parsing cleaner.
> 
> 
> Simple attribute:value pairs are indeed easier to parse in code. At the
> moment, the syntax allows for lists in nserver: attributes, so a user
> could, in theory, submit something like this:
> 
> nserver: ns1.example.com   # first name server
>   192.0.2.1   # IPv4 address of name server
>   2001:db8::1 # IPv6 address of name server
>   ns2.example.com 192.0.2.2 2001:db8::2  # name server and glue together

I didn't even think about that possibility :-)

> This is quite complex to parse, because the code has to deal with the
> comments and continuation lines, and then try to make sense of what is a
> name server and what is glue in that single line.
> 
> There are currently 599900 domain objects in the RIPE Database, of which
> only 18 use the list syntax in nserver attributes. We have to maintain
> extra code just to deal with these, so we would really like it if the
> syntax were restricted to simple attribute:value pairs.

This settles it for me.

>>OTOH, unless implicitely required by business rules or otherwise, I presume
>>it would be allowed to submit
>>
>>nserver: ns1.2.0.192.in-addr.arpa 192.0.2.1
>>nserver: ns2.2.0.192.in-addr.arpa 2001:db8::2
>>nserver: ns1.2.0.192.in-addr.arpa 2001:db8::1
>>nserver: ns2.2.0.192.in-addr.arpa 2001:db8::2
>>
>>or any other permutations? Leading to complex value gathering code again...
> 
> 
> Yes, this would of course be allowed. The code to handle these would
> simply transform each line into the following DNS records:
> 
> ns1.2.0.192.in-addr.arpa 172800 IN A 192.0.2.1
> ns2.2.0.192.in-addr.arpa 172800 IN AAAA 2001:db8::2
> ns1.2.0.192.in-addr.arpa 172800 IN AAAA 2001:db8::1
> ns2.2.0.192.in-addr.arpa 172800 IN AAAA 2001:db8::2

ACK, I was making up complexity in my mind which isn't necessary.

> In a DNS zone, the order of the records does not matter, and the DNS
> server into which this zone is loaded will handle it (duplicates would
> be discarded too). The code to turn such nserver attributes into DNS
> records is not at all complex.
> 
> 
>>>It would appear more natural to me to list all IP addresses on a single line
>>>after the name server's name.
> 
> 
> This does look more natural. However, we'd have to write code to expect
> the following:
> 
> nserver: ns1.example.com <addr1> <addr2> ... <addrN>
> 
> This is easier to parse than the current list syntax, but code would
> still have to transform this into appropriate records for delegation
> testing and eventual delegation.
> 
> We still prefer the simple syntax of:
> 
> nserver: name <optional address>
> 
> However, we're quite eager to hear from our users to see what they think.

Of course.

> Regards,
> 
> Anand Buddhdev
> RIPE NCC

Wilfried
(not wearing any hats, writing just as an LIR Manager)