def setUp(self):
        super(APIControllerWithRBACTestCase, self).setUp()

        self.users = {}
        self.roles = {}

        # Run RBAC migrations
        run_all_rbac_migrations()

        # Insert mock users with default role assignments
        role_names = [SystemRole.SYSTEM_ADMIN, SystemRole.ADMIN, SystemRole.OBSERVER]
        for role_name in role_names:
            user_db = UserDB(name=role_name)
            user_db = User.add_or_update(user_db)
            self.users[role_name] = user_db

            role_assignment_db = UserRoleAssignmentDB(
                user=user_db.name,
                role=role_name)
            UserRoleAssignment.add_or_update(role_assignment_db)

        # Insert a user with no permissions and role assignments
        user_1_db = UserDB(name='no_permissions')
        user_1_db = User.add_or_update(user_1_db)
        self.users['no_permissions'] = user_1_db

    def setUp(self):
        super(WebhookPermissionsResolverTestCase, self).setUp()

        # Create some mock users
        user_1_db = UserDB(name='custom_role_webhook_grant')
        user_1_db = User.add_or_update(user_1_db)
        self.users['custom_role_webhook_grant'] = user_1_db

        # Create some mock resources on which permissions can be granted
        webhook_1_db = WebhookDB(name='st2/')
        self.resources['webhook_1'] = webhook_1_db

        # Create some mock roles with associated permission grants
        # Custom role - "webhook_send" grant on webhook_1
        grant_db = PermissionGrantDB(resource_uid=self.resources['webhook_1'].get_uid(),
                                     resource_type=ResourceType.WEBHOOK,
                                     permission_types=[PermissionType.WEBHOOK_SEND])
        grant_db = PermissionGrant.add_or_update(grant_db)
        permission_grants = [str(grant_db.id)]
        role_db = RoleDB(name='custom_role_webhook_grant',
                         permission_grants=permission_grants)
        role_db = Role.add_or_update(role_db)
        self.roles['custom_role_webhook_grant'] = role_db

        # Create some mock role assignments
        user_db = self.users['custom_role_webhook_grant']
        role_assignment_db = UserRoleAssignmentDB(
            user=user_db.name, role=self.roles['custom_role_webhook_grant'].name,
            source='assignments/%s.yaml' % user_db.name)
        UserRoleAssignment.add_or_update(role_assignment_db)

    def setUp(self):
        super(RBACRoleAssignmentsControllerRBACTestCase, self).setUp()

        # Insert mock users, roles and assignments
        self.role_assignments = {}

        # Users
        user_1_db = UserDB(name='user_foo')
        user_1_db = User.add_or_update(user_1_db)
        self.users['user_foo'] = user_1_db

        # Roles
        role_1_db = RoleDB(name='user_foo', permission_grants=[])
        role_1_db = Role.add_or_update(role_1_db)
        self.roles['user_foo'] = role_1_db

        # Role assignments
        role_assignment_db = UserRoleAssignmentDB(
            user=self.users['user_foo'].name,
            role=self.roles['user_foo'].name,
            source='assignments/%s.yaml' % self.users['user_foo'].name)
        UserRoleAssignment.add_or_update(role_assignment_db)
        self.role_assignments['assignment_one'] = role_assignment_db

        role_assignment_db = UserRoleAssignmentDB(
            user='user_bar',
            role=self.roles['user_foo'].name,
            source='assignments/user_bar.yaml')
        UserRoleAssignment.add_or_update(role_assignment_db)
        self.role_assignments['assignment_two'] = role_assignment_db

    def _sync_user_role_assignments(self, user_db, role_assignment_dbs, role_assignment_api):
        """
        Synchronize role assignments for a particular user.

        :param user_db: User to synchronize the assignments for.
        :type user_db: :class:`UserDB`

        :param role_assignment_dbs: Existing user role assignments.
        :type role_assignment_dbs: ``list`` of :class:`UserRoleAssignmentDB`

        :param role_assignment_api: Role assignment API for a particular user.
        :param role_assignment_api: :class:`UserRoleAssignmentFileFormatAPI`

        :rtype: ``tuple``
        """
        db_role_names = [role_assignment_db.role for role_assignment_db in role_assignment_dbs]
        db_role_names = set(db_role_names)
        api_role_names = role_assignment_api.roles if role_assignment_api else []
        api_role_names = set(api_role_names)

        # A list of new assignments which should be added to the database
        new_role_names = api_role_names.difference(db_role_names)

        # A list of assgignments which need to be updated in the database
        updated_role_names = db_role_names.intersection(api_role_names)

        # A list of assignments which should be removed from the database
        removed_role_names = db_role_names - api_role_names

        LOG.debug('New assignments for user "%s": %r' % (user_db.name, new_role_names))
        LOG.debug('Updated assignments for user "%s": %r' % (user_db.name, updated_role_names))
        LOG.debug('Removed assignments for user "%s": %r' % (user_db.name, removed_role_names))

        # Build a list of role assignments to delete
        role_names_to_delete = updated_role_names.union(removed_role_names)
        role_assignment_dbs_to_delete = [
            role_assignment_db
            for role_assignment_db in role_assignment_dbs
            if role_assignment_db.role in role_names_to_delete
        ]

        UserRoleAssignment.query(user=user_db.name, role__in=role_names_to_delete).delete()
        LOG.debug('Removed %s assignments for user "%s"' % (len(role_assignment_dbs_to_delete), user_db.name))

        # Build a list of roles assignments to create
        role_names_to_create = new_role_names.union(updated_role_names)
        role_dbs_to_assign = Role.query(name__in=role_names_to_create)

        created_role_assignment_dbs = []
        for role_db in role_dbs_to_assign:
            if role_db.name in role_assignment_api.roles:
                description = getattr(role_assignment_api, "description", None)
            else:
                description = None
            assignment_db = rbac_services.assign_role_to_user(role_db=role_db, user_db=user_db, description=description)
            created_role_assignment_dbs.append(assignment_db)

        LOG.debug('Created %s new assignments for user "%s"' % (len(role_dbs_to_assign), user_db.name))

        return (created_role_assignment_dbs, role_assignment_dbs_to_delete)

    def setUp(self):
        super(ActionControllerRBACTestCase, self).setUp()
        self.fixtures_loader.save_fixtures_to_db(fixtures_pack=FIXTURES_PACK,
                                                 fixtures_dict=TEST_FIXTURES)

        file_name = 'action1.yaml'
        ActionControllerRBACTestCase.ACTION_1 = self.fixtures_loader.load_fixtures(
            fixtures_pack=FIXTURES_PACK,
            fixtures_dict={'actions': [file_name]})['actions'][file_name]

        # Insert mock users, roles and assignments

        # Users
        user_2_db = UserDB(name='action_create')
        user_2_db = User.add_or_update(user_2_db)
        self.users['action_create'] = user_2_db

        # Roles
        # action_create grant on parent pack
        grant_db = PermissionGrantDB(resource_uid='pack:examples',
                                     resource_type=ResourceType.PACK,
                                     permission_types=[PermissionType.ACTION_CREATE])
        grant_db = PermissionGrant.add_or_update(grant_db)
        permission_grants = [str(grant_db.id)]
        role_1_db = RoleDB(name='action_create', permission_grants=permission_grants)
        role_1_db = Role.add_or_update(role_1_db)
        self.roles['action_create'] = role_1_db

        # Role assignments
        user_db = self.users['action_create']
        role_assignment_db = UserRoleAssignmentDB(
            user=user_db.name,
            role=self.roles['action_create'].name)
        UserRoleAssignment.add_or_update(role_assignment_db)

    def setUp(self):
        super(ExecutionViewsFiltersControllerRBACTestCase, self).setUp()

        # Insert mock users, roles and assignments

        # Users
        user_1_db = UserDB(name='execution_views_filters_list')
        user_1_db = User.add_or_update(user_1_db)
        self.users['execution_views_filters_list'] = user_1_db

        # Roles
        # trace_list
        permission_types = [PermissionType.EXECUTION_VIEWS_FILTERS_LIST]
        grant_db = PermissionGrantDB(resource_uid=None,
                                     resource_type=ResourceType.EXECUTION,
                                     permission_types=permission_types)
        grant_db = PermissionGrant.add_or_update(grant_db)
        permission_grants = [str(grant_db.id)]
        role_1_db = RoleDB(name='execution_views_filters_list',
                           permission_grants=permission_grants)
        role_1_db = Role.add_or_update(role_1_db)
        self.roles['execution_views_filters_list'] = role_1_db

        # Role assignments
        role_assignment_db = UserRoleAssignmentDB(
            user=self.users['execution_views_filters_list'].name,
            role=self.roles['execution_views_filters_list'].name,
            source='assignments/%s.yaml' % self.users['execution_views_filters_list'].name)
        UserRoleAssignment.add_or_update(role_assignment_db)

    def setUp(self):
        super(PolicyTypeControllerRBACTestCase, self).setUp()
        self.models = self.fixtures_loader.save_fixtures_to_db(fixtures_pack=FIXTURES_PACK,
                                                               fixtures_dict=TEST_FIXTURES)

        file_name = 'fake_policy_type_1.yaml'
        PolicyTypeControllerRBACTestCase.POLICY_TYPE_1 = self.fixtures_loader.load_fixtures(
            fixtures_pack=FIXTURES_PACK,
            fixtures_dict={'policytypes': [file_name]})['policytypes'][file_name]

        file_name = 'fake_policy_type_2.yaml'
        PolicyTypeControllerRBACTestCase.POLICY_TYPE_2 = self.fixtures_loader.load_fixtures(
            fixtures_pack=FIXTURES_PACK,
            fixtures_dict={'policytypes': [file_name]})['policytypes'][file_name]

        # Insert mock users, roles and assignments

        # Users
        user_1_db = UserDB(name='policy_type_list')
        user_1_db = User.add_or_update(user_1_db)
        self.users['policy_type_list'] = user_1_db

        user_2_db = UserDB(name='policy_type_view')
        user_2_db = User.add_or_update(user_2_db)
        self.users['policy_type_view'] = user_2_db

        # Roles
        # policy_type_list
        grant_db = PermissionGrantDB(resource_uid=None,
                                     resource_type=ResourceType.POLICY_TYPE,
                                     permission_types=[PermissionType.POLICY_TYPE_LIST])
        grant_db = PermissionGrant.add_or_update(grant_db)
        permission_grants = [str(grant_db.id)]
        role_1_db = RoleDB(name='policy_type_list', permission_grants=permission_grants)
        role_1_db = Role.add_or_update(role_1_db)
        self.roles['policy_type_list'] = role_1_db

        # policy_type_view on timer 1
        policy_type_uid = self.models['policytypes']['fake_policy_type_1.yaml'].get_uid()
        grant_db = PermissionGrantDB(resource_uid=policy_type_uid,
                                     resource_type=ResourceType.POLICY_TYPE,
                                     permission_types=[PermissionType.POLICY_TYPE_VIEW])
        grant_db = PermissionGrant.add_or_update(grant_db)
        permission_grants = [str(grant_db.id)]
        role_1_db = RoleDB(name='policy_type_view', permission_grants=permission_grants)
        role_1_db = Role.add_or_update(role_1_db)
        self.roles['policy_type_view'] = role_1_db

        # Role assignments
        role_assignment_db = UserRoleAssignmentDB(
            user=self.users['policy_type_list'].name,
            role=self.roles['policy_type_list'].name,
            source='assignments/%s.yaml' % self.users['policy_type_list'].name)
        UserRoleAssignment.add_or_update(role_assignment_db)

        role_assignment_db = UserRoleAssignmentDB(
            user=self.users['policy_type_view'].name,
            role=self.roles['policy_type_view'].name,
            source='assignments/%s.yaml' % self.users['policy_type_view'].name)
        UserRoleAssignment.add_or_update(role_assignment_db)

    def setUp(self):
        super(RunnerPermissionsResolverTestCase, self).setUp()

        # Create some mock users
        user_1_db = UserDB(name='custom_role_runner_view_grant')
        user_1_db = User.add_or_update(user_1_db)
        self.users['custom_role_runner_view_grant'] = user_1_db

        user_2_db = UserDB(name='custom_role_runner_modify_grant')
        user_2_db = User.add_or_update(user_2_db)
        self.users['custom_role_runner_modify_grant'] = user_2_db

        # Create some mock resources on which permissions can be granted
        runner_1_db = RunnerTypeDB(name='runner_1')
        self.resources['runner_1'] = runner_1_db

        runner_2_db = RunnerTypeDB(name='runner_2')
        self.resources['runner_2'] = runner_2_db

        # Create some mock roles with associated permission grants
        # Custom role - "runner_view" grant on runner_1
        grant_db = PermissionGrantDB(resource_uid=self.resources['runner_1'].get_uid(),
                                     resource_type=ResourceType.RUNNER,
                                     permission_types=[PermissionType.RUNNER_VIEW])
        grant_db = PermissionGrant.add_or_update(grant_db)
        permission_grants = [str(grant_db.id)]
        role_db = RoleDB(name='custom_role_runner_view_grant',
                         permission_grants=permission_grants)
        role_db = Role.add_or_update(role_db)
        self.roles['custom_role_runner_view_grant'] = role_db

        # Custom role - "runner_modify" grant on runner_2
        grant_db = PermissionGrantDB(resource_uid=self.resources['runner_2'].get_uid(),
                                     resource_type=ResourceType.RUNNER,
                                     permission_types=[PermissionType.RUNNER_MODIFY])
        grant_db = PermissionGrant.add_or_update(grant_db)
        permission_grants = [str(grant_db.id)]
        role_db = RoleDB(name='custom_role_runner_modify_grant',
                         permission_grants=permission_grants)
        role_db = Role.add_or_update(role_db)
        self.roles['custom_role_runner_modify_grant'] = role_db

        # Create some mock role assignments
        user_db = self.users['custom_role_runner_view_grant']
        role_assignment_db = UserRoleAssignmentDB(
            user=user_db.name,
            role=self.roles['custom_role_runner_view_grant'].name)
        UserRoleAssignment.add_or_update(role_assignment_db)

        user_db = self.users['custom_role_runner_modify_grant']
        role_assignment_db = UserRoleAssignmentDB(
            user=user_db.name,
            role=self.roles['custom_role_runner_modify_grant'].name)
        UserRoleAssignment.add_or_update(role_assignment_db)

def revoke_role_from_user(role_db, user_db):
    """
    Revoke role from a user.

    :param role_db: Role to revoke.
    :type role_db: :class:`RoleDB`

    :param user_db: User to revoke the role from.
    :type user_db: :class:`UserDB`
    """
    role_assignment_db = UserRoleAssignment.get(user=user_db.name, role=role_db.name)
    result = UserRoleAssignment.delete(role_assignment_db)
    return result

    def setUp(self):
        super(WebhookControllerRBACTestCase, self).setUp()

        # Insert mock users, roles and assignments

        # Users
        user_1_db = UserDB(name='webhook_list')
        user_1_db = User.add_or_update(user_1_db)
        self.users['webhook_list'] = user_1_db

        user_2_db = UserDB(name='webhook_view')
        user_2_db = User.add_or_update(user_2_db)
        self.users['webhook_view'] = user_2_db

        # Roles
        # webhook_list
        grant_db = PermissionGrantDB(resource_uid=None,
                                     resource_type=ResourceType.WEBHOOK,
                                     permission_types=[PermissionType.WEBHOOK_LIST])
        grant_db = PermissionGrant.add_or_update(grant_db)
        permission_grants = [str(grant_db.id)]
        role_1_db = RoleDB(name='webhook_list', permission_grants=permission_grants)
        role_1_db = Role.add_or_update(role_1_db)
        self.roles['webhook_list'] = role_1_db

        # webhook_view on webhook 1 (git)
        name = 'git'
        webhook_db = WebhookDB(name=name)
        webhook_uid = webhook_db.get_uid()
        grant_db = PermissionGrantDB(resource_uid=webhook_uid,
                                     resource_type=ResourceType.WEBHOOK,
                                     permission_types=[PermissionType.WEBHOOK_VIEW])
        grant_db = PermissionGrant.add_or_update(grant_db)
        permission_grants = [str(grant_db.id)]
        role_1_db = RoleDB(name='webhook_view', permission_grants=permission_grants)
        role_1_db = Role.add_or_update(role_1_db)
        self.roles['webhook_view'] = role_1_db

        # Role assignments
        role_assignment_db = UserRoleAssignmentDB(
            user=self.users['webhook_list'].name,
            role=self.roles['webhook_list'].name,
            source='assignments/%s.yaml' % self.users['webhook_list'].name)
        UserRoleAssignment.add_or_update(role_assignment_db)

        role_assignment_db = UserRoleAssignmentDB(
            user=self.users['webhook_view'].name,
            role=self.roles['webhook_view'].name,
            source='assignments/%s.yaml' % self.users['webhook_view'].name)
        UserRoleAssignment.add_or_update(role_assignment_db)

    def setUp(self):
        super(APIControllersRBACTestCase, self).setUp()

        # Register packs
        if self.register_packs:
            self._register_packs()

        # Insert mock objects - those objects are used to test get one, edit and delete operations
        self.models = self.fixtures_loader.save_fixtures_to_db(fixtures_pack=FIXTURES_PACK,
                                                               fixtures_dict=TEST_FIXTURES)

        self.role_assignment_db_model = UserRoleAssignmentDB(
            user='user', role='role', source='assignments/user.yaml')
        UserRoleAssignment.add_or_update(self.role_assignment_db_model)

def revoke_role_from_user(role_db, user_db):
    """
    Revoke role from a user.

    :param role_db: Role to revoke.
    :type role_db: :class:`RoleDB`

    :param user_db: User to revoke the role from.
    :type user_db: :class:`UserDB`
    """
    role_assignment_dbs = UserRoleAssignment.query(user=user_db.name, role=role_db.name)

    for role_assignment_db in role_assignment_dbs:
        UserRoleAssignment.delete(role_assignment_db)

def get_all_permission_grants_for_user(user_db, resource_uid=None, resource_types=None, permission_types=None):
    """
    Retrieve all the permission grants for a particular user optionally filtering on:

    - Resource uid
    - Resource types
    - Permission types

    The result is a union of all the permission grants assigned to the roles which are assigned to
    the user.

    :rtype: ``list`` or :class:`PermissionGrantDB`
    """
    role_names = UserRoleAssignment.query(user=user_db.name).only("role").scalar("role")
    permission_grant_ids = Role.query(name__in=role_names).scalar("permission_grants")
    permission_grant_ids = sum(permission_grant_ids, [])

    permission_grants_filters = {}
    permission_grants_filters["id__in"] = permission_grant_ids

    if resource_uid:
        permission_grants_filters["resource_uid"] = resource_uid

    if resource_types:
        permission_grants_filters["resource_type__in"] = resource_types

    if permission_types:
        permission_grants_filters["permission_types__in"] = permission_types

    permission_grant_dbs = PermissionGrant.query(**permission_grants_filters)
    return permission_grant_dbs

def get_role_assignments_for_user(user_db):
    """
    Retrieve all the UserRoleAssignmentDB objects for a particular user.

    :param user_db: User to retrieve the role assignments for.
    :type user_db: :class:`UserDB`

    :rtype: ``list`` of :class:`UserRoleAssignmentDB`
    """
    result = UserRoleAssignment.query(user=user_db.name)
    return result

    def setUp(self):
        super(RBACControllerTestCase, self).setUp()

        permissions = [PermissionType.RULE_CREATE,
                       PermissionType.RULE_VIEW,
                       PermissionType.RULE_MODIFY,
                       PermissionType.RULE_DELETE]

        for name in permissions:
            user_db = UserDB(name=name)
            user_db = User.add_or_update(user_db)
            self.users[name] = user_db

            # Roles
            # action_create grant on parent pack
            grant_db = PermissionGrantDB(resource_uid='pack:examples',
                                         resource_type=ResourceType.PACK,
                                         permission_types=[name])
            grant_db = PermissionGrant.add_or_update(grant_db)
            grant_2_db = PermissionGrantDB(resource_uid='action:wolfpack:action-1',
                                           resource_type=ResourceType.ACTION,
                                           permission_types=[PermissionType.ACTION_EXECUTE])
            grant_2_db = PermissionGrant.add_or_update(grant_2_db)
            permission_grants = [str(grant_db.id), str(grant_2_db.id)]
            role_db = RoleDB(name=name, permission_grants=permission_grants)
            role_db = Role.add_or_update(role_db)
            self.roles[name] = role_db

            # Role assignments
            role_assignment_db = UserRoleAssignmentDB(
                user=user_db.name,
                role=role_db.name,
                source='assignments/%s.yaml' % user_db.name)
            UserRoleAssignment.add_or_update(role_assignment_db)

        role_assignment_db = UserRoleAssignmentDB(
            user='user_two',
            role='role_two',
            source='assignments/user_two.yaml',
            is_remote=True)
        UserRoleAssignment.add_or_update(role_assignment_db)

    def setUp(self):
        super(ActionViewsControllerRBACTestCase, self).setUp()
        self.models = self.fixtures_loader.save_fixtures_to_db(fixtures_pack=FIXTURES_PACK,
                                                               fixtures_dict=TEST_FIXTURES)

        file_name = 'a1.yaml'
        ActionViewsControllerRBACTestCase.ACTION_1 = self.fixtures_loader.load_fixtures(
            fixtures_pack=FIXTURES_PACK,
            fixtures_dict={'actions': [file_name]})['actions'][file_name]

        file_name = 'a2.yaml'
        ActionViewsControllerRBACTestCase.ACTION_1 = self.fixtures_loader.load_fixtures(
            fixtures_pack=FIXTURES_PACK,
            fixtures_dict={'actions': [file_name]})['actions'][file_name]

        # Insert mock users, roles and assignments

        # Users
        user_2_db = UserDB(name='action_view_a1')
        user_2_db = User.add_or_update(user_2_db)
        self.users['action_view_a1'] = user_2_db

        # Roles

        # action_view on a1
        action_uid = self.models['actions']['a1.yaml'].get_uid()
        grant_db = PermissionGrantDB(resource_uid=action_uid,
                                     resource_type=ResourceType.ACTION,
                                     permission_types=[PermissionType.ACTION_VIEW])
        grant_db = PermissionGrant.add_or_update(grant_db)
        permission_grants = [str(grant_db.id)]
        role_1_db = RoleDB(name='action_view_a1', permission_grants=permission_grants)
        role_1_db = Role.add_or_update(role_1_db)
        self.roles['action_view_a1'] = role_1_db

        # Role assignments
        role_assignment_db = UserRoleAssignmentDB(
            user=self.users['action_view_a1'].name,
            role=self.roles['action_view_a1'].name,
            source='assignments/%s.yaml' % self.users['action_view_a1'].name)
        UserRoleAssignment.add_or_update(role_assignment_db)

def get_roles_for_user(user_db):
    """
    Retrieve all the roles assigned to the provided user.

    :param user_db: User to retrieve the roles for.
    :type user_db: :class:`UserDB`

    :rtype: ``list`` of :class:`RoleDB`
    """
    role_names = UserRoleAssignment.query(user=user_db.name).only("role").scalar("role")
    result = Role.query(name__in=role_names)
    return result

    def _insert_common_mock_role_assignments(self):
        # Insert common mock role assignments
        role_assignment_admin = UserRoleAssignmentDB(
            user=self.users['admin'].name, role=self.roles['admin_role'].name,
            source='assignments/admin.yaml')

        role_assignment_admin = UserRoleAssignment.add_or_update(role_assignment_admin)

        role_assignment_observer = UserRoleAssignmentDB(
            user=self.users['observer'].name, role=self.roles['observer_role'].name,
            source='assignments/observer.yaml')

        role_assignment_observer = UserRoleAssignment.add_or_update(role_assignment_observer)

        user_db = self.users['1_custom_role_no_permissions']
        role_assignment_db = UserRoleAssignmentDB(
            user=user_db.name, role=self.roles['custom_role_1'].name,
            source='assignments/%s.yaml' % user_db.name)

        UserRoleAssignment.add_or_update(role_assignment_db)

        user_db = self.users['custom_role_pack_grant']
        role_assignment_db = UserRoleAssignmentDB(
            user=user_db.name, role=self.roles['custom_role_pack_grant'].name,
            source='assignments/%s.yaml' % user_db.name)

        UserRoleAssignment.add_or_update(role_assignment_db)

def assign_role_to_user(role_db, user_db):
    """
    Assign role to a user.

    :param role_db: Role to assign.
    :type role_db: :class:`RoleDB`

    :param user_db: User to assign the role to.
    :type user_db: :class:`UserDB`
    """
    role_assignment_db = UserRoleAssignmentDB(user=user_db.name, role=role_db.name)
    role_assignment_db = UserRoleAssignment.add_or_update(role_assignment_db)
    return role_assignment_db

def assign_role_to_user(role_db, user_db, description=None, is_remote=False, source=None,
                        ignore_already_exists_error=False):
    """
    Assign role to a user.

    :param role_db: Role to assign.
    :type role_db: :class:`RoleDB`

    :param user_db: User to assign the role to.
    :type user_db: :class:`UserDB`

    :param description: Optional assingment description.
    :type description: ``str``

    :param include_remote: True if this a remote assignment.
    :type include_remote: ``bool``

    :param source: Source from where this assignment comes from. For example, path of a file if
                   it's a local assignment or mapping or "API".
    :type source: ``str``

    :param: ignore_already_exists_error: True to ignore error if an assignment already exists.
    :type ignore_already_exists_error: ``bool``
    """
    role_assignment_db = UserRoleAssignmentDB(user=user_db.name, role=role_db.name, source=source,
                                              description=description, is_remote=is_remote)

    try:
        role_assignment_db = UserRoleAssignment.add_or_update(role_assignment_db)
    except (NotUniqueError, StackStormDBObjectConflictError) as e:
        if not ignore_already_exists_error:
            raise e

        role_assignment_db = UserRoleAssignment.query(user=user_db.name, role=role_db.name,
                                                      source=source,
                                                      description=description).first()

    return role_assignment_db