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Class: Mongo::Srv::Resolver Private

Do not use. This class is for internal use only.
Relationships & Source Files
Super Chains via Extension / Inclusion / Inheritance
Instance Chain:
self, ::Mongo::Loggable
Inherits: Object
Defined in: lib/mongo/srv/resolver.rb

Overview

Encapsulates the necessary behavior for querying SRV records as required by the driver.

Constant Summary

::Mongo::Loggable - Included

PREFIX

Class Method Summary

Instance Attribute Summary

Instance Method Summary

::Mongo::Loggable - Included

#log_debug

Convenience method to log debug messages with the standard prefix.
#log_error

Convenience method to log error messages with the standard prefix.
#log_fatal

Convenience method to log fatal messages with the standard prefix.
#log_info

Convenience method to log info messages with the standard prefix.
#log_warn

Convenience method to log warn messages with the standard prefix.
#logger

Get the logger instance.
#_mongo_log_prefix, #format_message

Instance Attribute Details

#options ⇒ Hash (readonly)

Returns:

  • (Hash) —

    Resolver options.

[ GitHub ] 

  


# File 'lib/mongo/srv/resolver.rb', line 58



attr_reader :options


  








  

    #raise_on_invalid?  ⇒ Boolean  (readonly, private)
  



  

    

Checks whether an error should be raised due to either a record with a mismatched domain being found or no records being found.


  





  
Returns:


    
  
  • 
    (Boolean)
—    
    

    Whether an error should be raised.
    

    
  
    • 





  [ GitHub ]


  

  


# File 'lib/mongo/srv/resolver.rb', line 153



def raise_on_invalid?
  @raise_on_invalid ||= @options[:raise_on_invalid] || true
end


  







Instance Method Details



  

    #get_records(hostname, srv_service_name = nil, srv_max_hosts = nil)  ⇒ Mongo::Srv::Result 
  



  

    

Obtains all of the SRV records for a given hostname. If a srv_max_hosts is specified and it is greater than 0, return maximum srv_max_hosts records.



In the event that a record with a mismatched domain is found or no records are found, if the :raise_on_invalid option is true, an exception will be raised, otherwise a warning will be logged.


  





  
Parameters:


    
  
  • 
    hostname
    (String)
—    
    

    The hostname whose records should be obtained.
    

    
  
    • 
  
  • 
    srv_service_name
    (String | nil)
    (defaults to: nil)
—    
    

    The SRV service name for the DNS query. If nil, ‘mongodb’ is used.
    

    
  
    • 
  
  • 
    srv_max_hosts
    (Integer | nil)
    (defaults to: nil)
—    
    

    The maximum number of records to return. If this value is nil, return all of the records.
    

    
  
    • 



Returns:



Raises:





  [ GitHub ]


  

  


# File 'lib/mongo/srv/resolver.rb', line 84



def get_records(hostname, srv_service_name=nil, srv_max_hosts=nil)
  query_name = record_prefix(srv_service_name) + hostname
  resources = @resolver.getresources(query_name, Resolv::DNS::Resource::IN::SRV)

  # Collect all of the records into a Result object, raising an error
  # or logging a warning if a record with a mismatched domain is found.
  # Note that in the case a warning is raised, the record is _not_
  # added to the Result object.
  result = Srv::Result.new(hostname)
  resources.each do |record|
    begin
      result.add_record(record)
    rescue Error::MismatchedDomain => e
      if raise_on_invalid?
        raise
      else
        log_warn(e.message)
      end
    end
  end

  # If no records are found, either raise an error or log a warning
  # based on the Resolver's :raise_on_invalid option.
  if result.empty?
    if raise_on_invalid?
      raise Error::NoSRVRecords.new(URI::SRVProtocol::NO_SRV_RECORDS % hostname)
    else
      log_warn(URI::SRVProtocol::NO_SRV_RECORDS % hostname)
    end
  end

  # if srv_max_hosts is in [1, #addresses)
  if (1...result.address_strs.length).include? srv_max_hosts
    sampled_records = resources.shuffle.first(srv_max_hosts)
    result = Srv::Result.new(hostname)
    sampled_records.each { |record| result.add_record(record) }
  end
  result
end


  








  

    #get_txt_options_string(hostname)  ⇒ nil | String 
  



  

    

Obtains the TXT records of a host.


  





  
Parameters:


    
  
  • 
    hostname
    (String)
—    
    

    The host whose TXT records should be obtained.
    

    
  
    • 



Returns:


    
  
  • 
    (nil | String)
—    
    

    ::Mongo::URI options string from TXT record associated with the hostname, or nil if there is no such record.
    

    
  
    • 



Raises:





  [ GitHub ]


  

  


# File 'lib/mongo/srv/resolver.rb', line 132



def get_txt_options_string(hostname)
  records = @resolver.getresources(hostname, Resolv::DNS::Resource::IN::TXT)
  if records.empty?
    return nil
  end

  if records.length > 1
    msg = "Only one TXT record is allowed: querying hostname #{hostname} returned #{records.length} records"

    raise Error::InvalidTXTRecord, msg
  end

  records[0].strings.join
end


  








  

    #record_prefix(srv_service_name = nil)  ⇒ String 
  



  

    

Generates the record prefix with a custom SRV service name if it is provided.


  





  
Parameters:


    
  
  • 
    srv_service_name
    (Hash)
    (defaults to: nil)
—    
    

    a customizable set of options
    

    
  
    • 


    
Options Hash (srv_service_name):

    
    
        
  • 
          The
          (String | nil)
            — 
    

    SRV service name to use in the record prefix.
    

            
    • 
    


Returns:


    
  
  • 
    (String)
—    
    

    The generated record prefix.
    

    
  
    • 





  [ GitHub ]


  

  


# File 'lib/mongo/srv/resolver.rb', line 38



def record_prefix(srv_service_name=nil)
  return srv_service_name ? "_#{srv_service_name}._tcp." : RECORD_PREFIX
end


  








  

    #timeout  
  

  [ GitHub ]


  

  


# File 'lib/mongo/srv/resolver.rb', line 60



def timeout
  options[:timeout] || Monitor::DEFAULT_TIMEOUT
end