Add cache for domain and record objects.

[people/stevee/pypdns.git] / backend.py

###############################################################################
#                                                                             #
# pyPDNS - A PDNS administration tool, written in pure python.                #
# Copyright (C) 2012 IPFire development team                                  #
#                                                                             #
# This program is free software: you can redistribute it and/or modify        #
# it under the terms of the GNU General Public License as published by        #
# the Free Software Foundation, either version 3 of the License, or           #
# (at your option) any later version.                                         #
#                                                                             #
# This program is distributed in the hope that it will be useful,             #
# but WITHOUT ANY WARRANTY; without even the implied warranty of              #
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the               #
# GNU General Public License for more details.                                #
#                                                                             #
# You should have received a copy of the GNU General Public License           #
# along with this program.  If not, see <http://www.gnu.org/licenses/>.       #
#                                                                             #
###############################################################################
#                                                                             #
# Basic information about the database layout can be found here:              #
# http://doc.powerdns.com/gsqlite.html                                        #
#                                                                             #
# More details about the database tables and fields can be found here:        #
# http://wiki.powerdns.com/trac/wiki/fields                                   #
#                                                                             #
###############################################################################

import database
import sqlite3

from errors import *

DB = "/var/lib/pdns/pdns.db"

# Create the primary DNS class.
class DNS(object):
	"""
	Primary DNS class.

	Uses the database class from imported database module.
	Connects to the PDNS sqlite database.
	"""
	def __init__(self, db):
		# Try to connect to database or raise an exception.
		try:
			self.db = database.Database(db)

		except sqlite3.OperationalError, e:
			raise DatabaseException, "Could not open database: %s" % e



	# Get all configured domains.
	def get_domains(self):
		"""
		Fetch all configured domains.
		"""
		# Create an empty list.
		domains = []

		# Add fetched domains to the previous created empty list.
		for row in self.db.query("SELECT id FROM domains"):
			domain = Domain(self, row.id)
			domains.append(domain)

		return domains

	# Get a domain by it's name.
	def get_domain(self, name):
		"""
		Get a domain by a given name.
		"""
		row = self.db.get("SELECT id FROM domains WHERE name = ?", name)

		# Check if an id has been returned from database, or return None.
		if not row:
			return None

		return Domain(self, row.id)


# Create Domain class.
class Domain(object):
	"""
	Domain class.

	Uses query method from database module to get requested information from domain.
	The domain is specified by it's unique database id.
	"""
	def __init__(self, dns, domain_id):
		self.dns = dns
		self.id = domain_id

		self.__data = None

	@property
	def db(self):
		return self.dns.db

	# Cache.
	@property
	def data(self):
		if self.__data is None:
			self.__data = self.db.get("SELECT * FROM domains WHERE id = ?", self.id)
			assert self.__data

		return self.__data

	# Determine the name of the zone by a given id.
	@property
	def name(self):
		return self.data.name

	# Get information of the master nameserver from which the domain should be slaved.
	@property
	def master(self):
		return self.data.master

	# Fetch data of the last check from the domain.
	@property
	def last_check(self):
		return self.data.last_check

	# Get the type of the domain.
	@property
	def type(self):
		return self.data.type

	# Get the last notified serial of a used master domain.
	@property
	def notified_serial(self):
		return self.data.notified_serial

	# Gain if a certain host is a supermaster for a certain domain name.
	@property
	def account(self):
		return self.data.account

	# Get all records from zone.
	@property 
	def records(self):
		"""
		Get all records from the zone.
		"""
		# Fetch records from zone and categorize them into their different record types.
		for row in self.db.query("SELECT id, type FROM records WHERE domain_id = ?", self.id):
			if row.type == "SOA":
				record = SOARecord(self, row.id)
			elif row.type == "A":
				record = ARecord(self, row.id)
			else:
				record = Record(self, row.id)

			yield record

	# Get records by a specified type.
	def get_records_by_type(self, type):
		records = []
		for record in self.records:
			if record.type == type:
				records.append(record)

		return records

	# Quick function to get the first SOA record from the domain.
	@property
	def SOA(self):
		records = self.get_records_by_type("SOA")
		if records:
			return records[0]


# Create class for domain records.
class Record(object):
	"""
	Record class

	It is used to get details about configured records.
	The domain and record is's are specified by their unique database id's.
	"""
	def __init__(self, domain, record_id):
		self.domain = domain
		self.id = record_id

		# Cache.
		self.__data = None

	@property
	def db(self):
		return self.domain.db

	@property
	def data(self):
		if self.__data is None:
			self.__data = self.db.get("SELECT * FROM records WHERE id = ?", self.id)
			assert self.__data

		return self.__data

	# Determine the type of the record.
	@property
	def type(self):
		return self.data.type

	# Get the configured DNS name of the record.
	@property
	def dnsname(self):
		return self.data.name


	# Fetch content like the address to which the record points.
	@property
	def content(self):
		return self.data.content

	# Get the "Time to live" for the record.
	@property
	def ttl(self):
		return self.data.ttl

	# Gain the configured record priority.
	@property
	def priority(self):
		return self.data.prio

	# Get the change_date.
	@property
	def change_date(self):
		return self.data.change_date

	# Fetch the ordername.
	@property
	def ordername(self):
		return self.data.ordername

	# Gain all information about records authentication.
	@property
	def authentication(self):
		return self.data.auth


# Create an own class to deal with "SOA" records.
class SOARecord(Record):
	"""
	SOA Record class.
	This is an own class to deal with "SOA" records.

	Uses splitt() to generate a list of the content string from the database.
	Returns the requested entries.
	"""
	def __init__(self, domain, record_id):
		Record.__init__(self, domain, record_id)

		self.soa_attrs = self.content.split()

		# Check if the content from database is valid (It contains all 7 required information).
		if not len(self.soa_attrs) == 7:
			raise InvalidRecordDataException, "Your SOA record \
				doesn't contain all required seven elements."

	# Primary NS - the domain name of the name server that was the original source of the data.	
	@property
	def mname(self):
		return self.soa_attrs[0]

	# E-mail address of the person which is responsible for this domain.
	@property
	def email(self):
		return self.soa_attrs[1]

	# The serial which increases allways after a change on the domain has been made.
	@property
	def serial(self):
		return self.soa_attrs[2]

	# The number of seconds between the time that a secondary name server gets a copy of the domain.
	@property
	def refresh(self):
		return self.soa_attrs[3]

	# The number of seconds during the next refresh attempt if the previous fails.
	@property
	def retry(self):
		return self.soa_attrs[4]

	# The number of seconds that lets the secondary name server(s) know how long they can hold the information.
	@property
	def expire(self):
		return self.soa_attrs[5]

	# The number of seconds that the records in the domain are valid.
	@property
	def minimum(self):
		return self.soa_attrs[6]



class ARecord(Record):
	pass