rspec-dns

rspec-dns is an rspec plugin for easy DNS testing. It uses dnsruby instead of the standard library for the name resolution.

If you're using bundler, add this line to your application's Gemfile:

gem 'rspec-dns'

Don't forget to run the bundle command to install.

Or install it manually with:

$ gem install rspec-dns

RSpec DNS is best described by example. First, require rspec-dns in your spec_helper.rb:

# spec/spec_helper.rb
require 'rspec'
require 'rspec-dns'

Then, create a spec like this:

require 'spec_helper'

describe 'www.example.com' do
  it { is_expected.to have_dns.with_type('TXT').and_ttl(300).and_data('a=b') }
end

Or group all your DNS tests into a single file or context:

require 'spec_helper'

describe 'DNS tests' do
  it 'passes some tests' do
    expect('www.example.com').to have_dns.with_type('TXT').and_ttl(300).and_data('a=b')
    expect('www.example.com').to have_dns.with_type('A').and_ttl(300).and_address('192.0.2.4')
    expect('192.0.2.4').to have_dns.with_type('PTR').and_domainname('www.example.com')
  end
end

Currently the following chaining methods are supported:

• at_least
• in_authority
• refuse_request
• config
• in_zone_file
• in_additional

Here's some usage examples:

  it 'checks if recursion is disabled' do
    expect('google.com').to have_dns.refuse_request
  end

  it 'checks if gslb subdomain is delegated to dynect' do
    expect('gslb.example.com').to have_dns.in_authority.with_type('NS').and_domainname(/dynect/).at_least(3)
  end

  it 'checks number of hosts in round robin' do
    expect('example.com').to have_dns.with_type('A').at_least(3)
  end

  it 'checks with configuration' do
    expect('example.com').to have_dns.with_type('A').config(nameserver: '192.0.2.4')
  end

  it 'checks zone file("example.zone") with specified origin("example.com.")' do
    expect('example.com').to have_dns.with_type('A').in_zone_file('example.zone', 'example.com.')
  end

  it 'checks if "sub" subdomain is delegated to "ns.sub.example.com (192.0.2.5)",' do
    expect('ns.sub.example.com').to have_dns.config(nameserver: 'ns.example.com', recurse: false)
      .in_additional.with_type('A').and_address('192.0.2.5')
  end

The other method chains are actually Dnsruby attributes on the record. You can prefix them with and_, with_, and_with or whatever your heart desires. The predicate is what is checked. The rest is syntactic sugar.

Depending on the type of record, the following attributes may be available:

• address
• bitmap
• cpu
• data
• domainname
• emailbx
• exchange
• expire
• minimum
• mname
• name
• os
• port
• preference
• priority
• protocol
• refresh
• retry
• rmailbx
• rname
• serial
• target
• ttl
• type
• weight

If you try checking an attribute on a record that is non-existent (like checking the rmailbx on an A record), you'll get an error like this:

Failure/Error: it { is_expected.to have_dns.with_type('TXT').and_ttl(300).and_data('a=b') }
  got 1 exception(s): undefined method `rmailbx' for #<Dnsruby::RR::IN::A:0x007f66a0339b00>

For this reason, you should always check the type attribute first in your chain.

All configurations can be in your project root at config/dns.yml. This YAML file directly corresponds to the Resolv DNS initializer.

For example, to directly query your DNS servers (necessary for correct TTL tests), create a config/dns.yml file like this:

nameserver:
  - 1.2.3.5
  - 6.7.8.9

If this file is missing Resolv will use the settings in /etc/resolv.conf. You can also configure with config chain.

  it 'checks with configuration' do
    expect('example.com').to have_dns
      .with_type('A').config(nameserver: '192.0.2.4', recurse: false)
  end

The full list of configuration options can be found on the Dnsruby docs (Config) and (Resolver#initialize).

Connection timeout is to stop waiting for resolver. If you want to wait over default timeout 1, you can change the timeout in spec files or spec_helpers like this:

RSpec.configuration.rspec_dns_connection_timeout = 5

alternatively you can specify it in the config/dns.yml file:

nameserver:
  - 1.2.3.5
  - 6.7.8.9
timeouts: 3

1. Fork the project on github
2. Create your feature branch
3. Open a Pull Request

• Seth Vargo (sethvargo@gmail.com)
• Johannes Russek (jrussek@spotify.com)
• Alexey Lapitsky (lex@realisticgroup.com)
• Hiroshi OTA (otahi.pub@gmail.com)

Copyright 2012-2013 Seth Vargo
Copyright 2012-2013 CustomInk, LLC
Copyright 2013-2014 Spotify AB
Copyright 2013-2014 Hiroshi OTA

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.