tempest/common/waiters.py

# vim: tabstop=4 shiftwidth=4 softtabstop=4

#    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 time

from tempest import config
from tempest import exceptions
from tempest.openstack.common import log as logging

CONFIG = config.TempestConfig()
LOG = logging.getLogger(__name__)


# NOTE(afazekas): This function needs to know a token and a subject.
def wait_for_server_status(client, server_id, status, ready_wait=True,
                           extra_timeout=0, raise_on_error=True):
    """Waits for a server to reach a given status."""

    def _get_task_state(body):
        task_state = body.get('OS-EXT-STS:task_state', None)
        return task_state

    # NOTE(afazekas): UNKNOWN status possible on ERROR
    # or in a very early stage.
    resp, body = client.get_server(server_id)
    old_status = server_status = body['status']
    old_task_state = task_state = _get_task_state(body)
    start_time = int(time.time())
    timeout = client.build_timeout + extra_timeout
    while True:
        # NOTE(afazekas): Now the BUILD status only reached
        # between the UNKOWN->ACTIVE transition.
        # TODO(afazekas): enumerate and validate the stable status set
        if status == 'BUILD' and server_status != 'UNKNOWN':
            return
        if server_status == status:
            if ready_wait:
                if status == 'BUILD':
                    return
                # NOTE(afazekas): The instance is in "ready for action state"
                # when no task in progress
                # NOTE(afazekas): Converted to string bacuse of the XML
                # responses
                if str(task_state) == "None":
                    # without state api extension 3 sec usually enough
                    time.sleep(CONFIG.compute.ready_wait)
                    return
            else:
                return

        time.sleep(client.build_interval)
        resp, body = client.get_server(server_id)
        server_status = body['status']
        task_state = _get_task_state(body)
        if (server_status != old_status) or (task_state != old_task_state):
            LOG.info('State transition "%s" ==> "%s" after %d second wait',
                     '/'.join((old_status, str(old_task_state))),
                     '/'.join((server_status, str(task_state))),
                     time.time() - start_time)
        if (server_status == 'ERROR') and raise_on_error:
            raise exceptions.BuildErrorException(server_id=server_id)

        timed_out = int(time.time()) - start_time >= timeout

        if timed_out:
            expected_task_state = 'None' if ready_wait else 'n/a'
            message = ('Server %(server_id)s failed to reach %(status)s '
                       'status and task state "%(expected_task_state)s" '
                       'within the required time (%(timeout)s s).' %
                       {'server_id': server_id,
                        'status': status,
                        'expected_task_state': expected_task_state,
                        'timeout': timeout})
            message += ' Current status: %s.' % server_status
            message += ' Current task state: %s.' % task_state
            raise exceptions.TimeoutException(message)
        old_status = server_status
        old_task_state = task_state