# designate.scheduler.filters.in_doubt_default_pool_filter

# Source code for designate.scheduler.filters.in_doubt_default_pool_filter

    # Copyright 2017 SAP SE
    #
    # Licensed under the Apache License, Version 2.0 (the "License"); you may
    # not use this file except in compliance with the License. You may obtain
    # a copy of the License at
    #
    #      http://www.apache.org/licenses/LICENSE-2.0
    #
    # Unless required by applicable law or agreed to in writing, software
    # distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
    # WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
    # License for the specific language governing permissions and limitations
    # under the License.
    import designate.conf
    from designate import objects
    from designate.scheduler.filters import base

    CONF = designate.conf.CONF

    class InDoubtDefaultPoolFilter(base.Filter):
        """If the previous filter(s) didn't make a clear selection of one pool
        and if the default pool is in the set of multiple pools, this filter will
        select the default pool.

        This filter will pass through the pool list, if there are one or
        less pools available to schedule to, or if the default pool is
        not in the set of multiple pools.

        .. note::

            This should be used as one of the last filters.

        """

        name = 'in_doubt_default_pool'
        """Name to enable in the ``[designate:central:scheduler].filters`` option
        list
        """

        def filter(self, context, pools, zone):
            if len(pools) > 1:
                default_pool_id = CONF['service:central'].default_pool_id
                try:
                    default_pool = self.storage.get_pool(context, default_pool_id)
                except Exception:
                    return pools

                if default_pool in pools:
                    pools = objects.PoolList()
                    pools.append(default_pool)

            return pools

this page last updated: 2026-08-19 02:25:39

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