`class Server`

Provides the core of the RubyDNS domain-specific language (DSL). It contains a list of rules which are used to match against incoming DNS questions. These rules are used to generate responses which are either DNS resource records or failures.

Definitions

`def initialize(...)`

Instantiate a server with a block

server = Server.new do match(/server.mydomain.com/, IN::A) do |transaction| transaction.respond!("1.2.3.4") end end

Implementation

def initialize(...)
	super
	
	@rules = []
	@otherwise = nil
end

`def match(*pattern, &block)`

This function connects a pattern with a block. A pattern is either a String or a Regex instance. Optionally, a second argument can be provided which is either a String, Symbol or Array of resource record types which the rule matches against.

match("www.google.com") match("gmail.com", IN::MX) match(/g?mail.(com|org|net)/, [IN::MX, IN::A])

Implementation

def match(*pattern, &block)
	@rules << Rule.new(pattern, block)
end

`def otherwise(&block)`

Specify a default block to execute if all other rules fail to match. This block is typially used to pass the request on to another server (i.e. recursive request).

otherwise do |transaction| transaction.passthrough!($R) end

Implementation

def otherwise(&block)
	@otherwise = block
end

`def next!`

If you match a rule, but decide within the rule that it isn't the correct one to use, you can call next! to evaluate the next rule - in other words, to continue falling down through the list of rules.

Implementation

def next!
	throw :next
end

`def process(name, resource_class, transaction)`

Give a name and a record type, try to match a rule and use it for processing the given arguments.

Implementation

def process(name, resource_class, transaction)
	Console.debug(self) {"<#{transaction.query.id}> Searching for #{name} #{resource_class.name}"}
	
	@rules.each do |rule|
		Console.debug(self) {"<#{transaction.query.id}> Checking rule #{rule}..."}
		
		catch (:next) do
			# If the rule returns true, we assume that it was successful and no further rules need to be evaluated.
			return if rule.call(self, name, resource_class, transaction)
		end
	end
	
	if @otherwise
		@otherwise.call(transaction)
	else
		@logger.warn "<#{transaction.query.id}> Failed to handle #{name} #{resource_class.name}!"
	end
end