dns-zone

A Ruby library for building and parsing DNS zone files.

Installation

Add this line to your Gemfile:

gem 'dns-zone'

And then execute:

bundle install

Require the gem in your code:

require 'dns/zone'

Usage

Loading a zone file

zone = DNS::Zone.load(zone_as_string)

Creating a new zone programmatically

zone = DNS::Zone.new
zone.origin = 'example.com.'
zone.ttl = '1d'

# quick access to SOA RR
zone.soa.nameserver = 'ns0.lividpenguin.com.'
zone.soa.email = 'hostmaster.lividpenguin.com.'

# add an A RR
rec = DNS::Zone::RR::A.new
rec.address = '127.0.0.1'
zone.records << rec

# output using dns zone file format
zone.dump

Development

Development Commands

# install external gem dependencies first
bundle install

# run all tests and build code coverage
bundle exec rake test

# hints where to improve docs
bundle exec inch

# watch for changes and run development commands (tests, documentation, etc)
bundle exec guard

TODO

Must have

[x] Ability to load a zone made of multiple RR's
[x] Add support for RR Type: SOA
[x] Add support for RR Type: NS
[x] Add support for RR Type: MX
[x] Add support for RR Type: AAAA
[x] Add support for RR Type: A
[x] Add support for RR Type: CNAME
[x] Add support for RR Type: TXT
[x] Add support for RR Type: SRV
[x] Add support for RR Type: PTR
[x] Add support for RR Type: SPF
[x] Add support for RR Type: HINFO
[x] Support loading zone where some records have an empty label

Would be nice

[ ] Handle parsing a zone file that uses more then one $ORIGIN directive.
[ ] Basic validation, error checking:
    [ ] Only one SOA per zone.
    [ ] CNAMEs can't use a label of `@`.
    [ ] PTR zones have some extra conditions:
        [ ] labels cant be repeted
        [ ] names should end in a dot, otherwise they are invalid after expansion
        [ ] IPv4 and IPv6 cant be mixed

[ ] Ability to 'include' defaults/records into a zone.
    This may or may not mean supporting the `$INCLUDE` directive.

At some point; low priority

[ ] Configuration options:
    [ ] spaces/tabs used between RR params in zone file output
    [ ] time format used in output (should parse both formats, seconds or bind time format (e.g. 1d))
        [ ] add comments to explain TTL's that are in seconds
[ ] Ability to add comment to RR (n.b. currently we strip comments when parsing)
[ ] Add support for RR Type: LOC (RFC 1876)
[ ] Add support for RR Type: DNAME
[ ] Add support for RR Type: DNSKEY
[ ] Add support for RR Type: DS
[ ] Add support for RR Type: KEY
[ ] Add support for RR Type: NSEC
[ ] Add support for RR Type: RRSIG
[ ] Add support for RR Type: NAPTR
[ ] Add support for RR Type: RP
[ ] Add support for RR Type: RT

Notes

• RR Format: [<TTL>] [<class>] <type> <RDATA>
• A DNS zone is built from RR's and a couple of other special directives.
• If zone file does not include $ORIGIN, it will be inferred by the zone "<zone-name>" {} clause from bind.conf In general we should always explicitly define an $ORIGIN directive unless there is a very good reason not to.
• RFC 1035 - Domain Names - Implementation and Specification
• RFC 2308 - Negative Caching of DNS Queries (DNS NCACHE)
• RFC 3596 - DNS Extensions to Support IP Version 6