Source code for freezer_dr.evacuators.common.manager

# (c) Copyright 2014,2015 Hewlett-Packard Development Company, L.P.
#
# 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.
from oslo_config import cfg
from oslo_log import log
from oslo_utils import importutils
from freezer_dr.fencers.common.manager import FencerManager
from time import sleep
from freezer_dr.evacuators.common.utils import get_nodes_details

CONF = cfg.CONF
LOG = log.getLogger(__name__)


class EvacuationManager(object):

    def __init__(self, enable_fencing=True):
        evcuation_conf = CONF.get('evacuation')
        self.driver = importutils.import_object(
            evcuation_conf.get('driver'),
            evcuation_conf.get('wait'),
            evcuation_conf.get('retries'),
            evcuation_conf.get('shared_storage'),
            **evcuation_conf.get('options')
        )
        self.enable_fencing = enable_fencing
        self.wait = evcuation_conf.get('wait')
        self.retires = evcuation_conf.get('retries', 1)
        if self.retires <= 0:
            self.retires = 1

    def evacuate(self, nodes):
        # try to disable node
        # @todo needs more error handling like if the status didn't update or
        # we are unable to disable the node ???
        failed_nodes = []  # maintain nodes that are going to fail at any state
        succeeded_nodes = []
        for node in nodes:
            for i in range(0, self.retires):
                status = self._disable_node(node)
                # if True ( node disabled ) break the loop
                if status:
                    break
                else:
                    status = False
            node['status'] = status
            # make sure the disable request was successful
            if not self.driver.get_node_status(node):
                failed_nodes.append(node)
                nodes.remove(node)  # if the node failed at any step no reason
                # to move it to the next step
            else:
                succeeded_nodes.append(node)

        nodes = succeeded_nodes
        if self.enable_fencing:
            fencer = FencerManager(nodes)
            nodes = fencer.fence()
        """
        @todo this code needs to be commented for the time being till we fix
         nova bug found in state, which always go up afer enable or disable. We
         will use get_node_details for the time being from the main script to
         get nodes details before evacuating ...
        succeeded_nodes = []
        for node in nodes:
            node['instances'] = self.driver.get_node_instances(node)
            succeeded_nodes.append(node)

        nodes = succeeded_nodes
        """
        # Start evacuation calls ...
        evacuated_nodes = []
        for i in range(0, self.retires):
            try:
                sleep(self.wait)
                nodes = self.driver.evacuate_nodes(nodes)
                if not nodes:
                    return evacuated_nodes
                evacuated_nodes = nodes
            except Exception as e:
                LOG.error(e)
        return evacuated_nodes

    def get_nodes_details(self, nodes):
        """
        To be re-structured after fixing the nova bug !
        :param nodes: list of nodes
        :return: list of node with more details
        """
        return get_nodes_details(nodes)

    def _disable_node(self, node):
        if not self.driver.is_node_disabled(node):
                return self.driver.disable_node(node)
        else:
            True