from __future__ import unicode_literals from django.db import models, transaction from django.dispatch import Signal from django.utils.encoding import python_2_unicode_compatible from django.utils.translation import ugettext as _ from model_utils import Choices from model_utils.models import TimeStampedModel from osusers.models import User as OsUser DB_TYPES = Choices( (0, 'pgsql', _('PostgreSQL')), (1, 'mysql', _('MySQL')), ) """ Database type choice enumeration. """ password_set = Signal(providing_args=['instance', 'password']) class DatabaseUserManager(models.Manager): """ Default Manager for :py:class:`userdbs.models.DatabaseUser`. """ def _get_next_dbuser_name(self, osuser, db_type): """ Get the next available database user name. :param osuser: :py:class:`osusers.models.User` instance :param db_type: value from :py:data:`DB_TYPES` :return: database user name :rtype: str """ count = 1 dbuser_name_format = "{0}db{{0:02d}}".format(osuser.username) nextname = dbuser_name_format.format(count) for user in self.values('name').filter( osuser=osuser, db_type=db_type ).order_by('name'): if user['name'] == nextname: count += 1 nextname = dbuser_name_format.format(count) else: break return nextname @transaction.atomic def create_database_user( self, osuser, db_type, username=None, password=None, commit=True ): """ Create a database user of the given type for the given OS user. If username or password are not specified they are generated. :param osuser: the :py:class:`osusers.models.User` instance :param db_type: value from :py:data:`DB_TYPES` :param str username: database user name :param str password: initial password or None :param boolean commit: whether the user should be persisted :return: :py:class:`userdbs.models.DatabaseUser` instance .. note:: The password is not persisted it is only used to set the password on the database side. """ if username is None: username = self._get_next_dbuser_name(osuser, db_type) db_user = DatabaseUser( osuser=osuser, db_type=db_type, name=username) if commit: db_user.save() return db_user @python_2_unicode_compatible class DatabaseUser(TimeStampedModel, models.Model): osuser = models.ForeignKey(OsUser) name = models.CharField( _('username'), max_length=63) db_type = models.PositiveSmallIntegerField( _('database type'), choices=DB_TYPES) objects = DatabaseUserManager() class Meta: unique_together = ['name', 'db_type'] verbose_name = _('database user') verbose_name_plural = _('database users') def __str__(self): return "%(name)s (%(db_type)s for %(osuser)s)" % { 'name': self.name, 'db_type': self.get_db_type_display(), 'osuser': self.osuser.username, } @transaction.atomic def set_password(self, password): """ Set an existing user's password. :param str password: new password for the database user """ password_set.send( sender=self.__class__, password=password, instance=self) @transaction.atomic def delete(self, *args, **kwargs): """ Delete the database user from the target database and the Django database. :param args: positional arguments for :py:meth:`django.db.models.Model.delete` :param kwargs: keyword arguments for :py:meth:`django.db.models.Model.delete` """ for database in self.userdatabase_set.all(): database.delete() super(DatabaseUser, self).delete(*args, **kwargs) class UserDatabaseManager(models.Manager): """ Default manager for :py:class:`userdbs.models.UserDatabase` instances. """ def _get_next_dbname(self, db_user): """ Get the next available database name for the given database user. :param db_user: :py:class:`userdbs.models.DatabaseUser` instance :return: database name :rtype: str """ count = 1 db_name_format = "{0}_{{0:02d}}".format(db_user.name) # first db is named the same as the user nextname = db_user.name for name in self.values('db_name').filter(db_user=db_user).order_by( 'db_name' ): if name['db_name'] == nextname: count += 1 nextname = db_name_format.format(count) else: break return nextname @transaction.atomic def create_userdatabase_with_user( self, db_type, osuser, password=None, commit=True): """ Creates a new user database with a new user. :param db_type: database type from :py:data:`DB_TYPES` :param osuser: :py:class:`osusers.models.OsUser` instance :param str password: the password of the new database user :param boolean commit: whether the user and the database should be persisted :return: database instance :rtype: :py:class:`UserDatabase` """ dbuser = DatabaseUser.objects.create_database_user( osuser, db_type, password=password, commit=commit) database = self.create_userdatabase(dbuser, commit=commit) return database @transaction.atomic def create_userdatabase(self, db_user, db_name=None, commit=True): """ Creates a new user database. :param db_user: :py:class:`userdbs.models.DatabaseUser` instance :param str db_name: database name :param boolean commit: whether the database should be persisted :return: :py:class:`userdbs.models.UserDatabase` instance """ if db_name is None: db_name = self._get_next_dbname(db_user) database = UserDatabase(db_user=db_user, db_name=db_name) if commit: database.save() return database @python_2_unicode_compatible class UserDatabase(TimeStampedModel, models.Model): # MySQL limits to 64, PostgreSQL to 63 characters db_name = models.CharField( _('database name'), max_length=63) db_user = models.ForeignKey(DatabaseUser, verbose_name=_('database user')) objects = UserDatabaseManager() class Meta: unique_together = ['db_name', 'db_user'] verbose_name = _('user database') verbose_name_plural = _('user specific database') def __str__(self): return "%(db_name)s (%(db_user)s)" % { 'db_name': self.db_name, 'db_user': self.db_user, }