Method: Async::DNS::System.resolver

Defined in:
lib/async/dns/system.rb

.resolver(**options) ⇒ Object

Get a list of standard nameserver connections which can be used for querying any standard servers that the system has been configured with. There is no equivalent facility to use the ‘hosts` file at present.



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# File 'lib/async/dns/system.rb', line 166

def self.resolver(**options)
  nameservers = []
  
  if File.exist? RESOLV_CONF
    options.update(parse_resolv_configuration(RESOLV_CONF))
    nameservers = options.delete(:nameservers)
  elsif defined?(Win32::Resolv) and RUBY_PLATFORM =~ /mswin32|cygwin|mingw|bccwin/
    search, nameservers = Win32::Resolv.get_resolv_info
    options.update(search: search)
  end
  
  if search = options[:search]
    unless search.include?(".")
      search << nil
    end
  else
    options[:search] = [nil]
  end
  
  if hosts = Hosts.local
    cache = options.fetch(:cache) do
      options[:cache] = Cache.new
    end
    
    hosts.each do |name, addresses|
      addresses.each do |address|
        resource = Resource.new(address, nil)
        case address
        when Resolv::IPv4
          cache.store(name, Resolv::DNS::Resource::IN::A, resource)
        when Resolv::IPv6
          cache.store(name, Resolv::DNS::Resource::IN::AAAA, resource)
        end
      end
    end
  end
  
  timeout = options.delete(:timeout) || DEFAULT_TIMEOUT
  endpoint = Endpoint.for(nameservers, timeout: timeout)
  
  if block_given?
    yield endpoint, **options
  else
    return Resolver.new(endpoint, **options)
  end
end