# (Re)announcing GoDNS


[ post updated to reflect changes in the library ]

This library <strike>takes a new, innovative and enterprise ready
approach</strike> sends and receives queries to and from the DNS. 

The
library was forked from the official DNS code in Go (in the `net`
package). Since that time Go team has thrown out this code and started
to use the system's C library via a wrapper. I was however struck by the elegance of the
code (esp. the `pack` and `unpack` functions), so I forked it and added
new record types (`AAAA`, `DS`, `RRSIG`, etc.) and turned into a more
general DNS API.

The API is slightly different than for instance,
[Net::DNS](http://www.net-dns.org/) or 
[Ldns](http://www.nlnetlabs.nl/projects/ldns/) in that
you must create the packet before you hand it over to the resolver:

    m := new(dns.Msg)
    m.MsgHdr.Recursion_desired = true
    m.Question = make([]dns.Question, 1)
    m.Question[0] = dns.Question{"miek.nl", dns.TypeSOA, dns.ClassINET}

This is more cumbersome than for instance, this (non-godns) code:
    
    r := new(dns.Resolver)
    r.Query("miek.nl", dns.TypeSOA, dns.ClassINET)

But... it does allow for much more flexibility, something that is
lacking (IMHO) in todays DNS libraries. Also the resolver object
has an optional call-back function that can transform the packet
just before it is put on the wire (`res.Mangle`). Also the
resolver runs in a seperate goroutine.

A short program that send, receives and prints out a packet goes something
like this:

    res := new(dns.Resolver)   // create a new resolver object
    res.Servers = []string{"127.0.0.1"}  // set the nameservers
    res.Attempts = 1

    m := new(dns.Msg)
    m.MsgHdr.Recursion_desired = true    // only set this bit
    m.Question = make([]dns.Question, 1) // Alloc space for a question
    // set the question
    m.Question[0] = dns.Question{"miek.nl", dns.TypeTXT, dns.ClassINET}

    in, err := res.Query(m)     // ask the question
    fmt.Printf("%v\n", in)      // print the reply message

# Code, license and URLs

The code can be found at [github](https://github.com/miekg/godns).
Listed on Go Dashboard under the [libs
section](http://godashboard.appspot.com/project?tag=lib).
The project page on `miek.nl` is [listed
here](/projects/godns/index.html).
It is licensed under the same license as the official Go code, because
it is forked from that.

There is lots of stuff that still needs implementing, a selection from the current list:

* EDNS - in a nice and transparent way;
* DNSSEC validation, DNSSEC types are already there of course;
* Better error handling;
* ...