waiters.py

#    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 os
import re
import time

from oslo_log import log as logging

from tempest import config
from tempest import exceptions
from tempest.lib.common.utils import test_utils
from tempest.lib import exceptions as lib_exc

CONF = config.CONF
LOG = logging.getLogger(__name__)


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


# 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,
                           request_id=None):
    """Waits for a server to reach a given status."""

    # NOTE(afazekas): UNKNOWN status possible on ERROR
    # or in a very early stage.
    body = client.show_server(server_id)['server']
    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 UNKNOWN->ACTIVE transition.
        # TODO(afazekas): enumerate and validate the stable status set
        if status == 'BUILD' and server_status != 'UNKNOWN':
            return body
        if server_status == status:
            if ready_wait:
                if status == 'BUILD':
                    return body
                # NOTE(afazekas): The instance is in "ready for action state"
                # when no task in progress
                if task_state is None:
                    # without state api extension 3 sec usually enough
                    time.sleep(CONF.compute.ready_wait)
                    return body
            else:
                return body

        time.sleep(client.build_interval)
        body = client.show_server(server_id)['server']
        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:
            details = ''
            if 'fault' in body:
                details += 'Fault: %s.' % body['fault']
            if request_id:
                details += ' Request ID of server operation performed before'
                details += ' checking the server status %s.' % request_id
            raise exceptions.BuildErrorException(details, 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})
            if request_id:
                message += ' Request ID of server operation performed before'
                message += ' checking the server status %s.' % request_id
            message += ' Current status: %s.' % server_status
            message += ' Current task state: %s.' % task_state
            caller = test_utils.find_test_caller()
            if caller:
                message = '(%s) %s' % (caller, message)
            raise lib_exc.TimeoutException(message)
        old_status = server_status
        old_task_state = task_state


def wait_for_server_termination(client, server_id, ignore_error=False,
                                request_id=None):
    """Waits for server to reach termination."""
    try:
        body = client.show_server(server_id)['server']
    except lib_exc.NotFound:
        return
    old_status = body['status']
    old_task_state = _get_task_state(body)
    start_time = int(time.time())
    while True:
        time.sleep(client.build_interval)
        try:
            body = client.show_server(server_id)['server']
        except lib_exc.NotFound:
            return
        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 not ignore_error:
            details = ("Server %s failed to delete and is in ERROR status." %
                       server_id)
            if 'fault' in body:
                details += ' Fault: %s.' % body['fault']
            if request_id:
                details += ' Server delete request ID: %s.' % request_id
            raise lib_exc.DeleteErrorException(details, server_id=server_id)

        if server_status == 'SOFT_DELETED':
            # Soft-deleted instances need to be forcibly deleted to
            # prevent some test cases from failing.
            LOG.debug("Automatically force-deleting soft-deleted server %s",
                      server_id)
            try:
                client.force_delete_server(server_id)
            except lib_exc.NotFound:
                # The instance may have been deleted so ignore
                # NotFound exception
                return

        if int(time.time()) - start_time >= client.build_timeout:
            raise lib_exc.TimeoutException
        old_status = server_status
        old_task_state = task_state


def wait_for_image_status(client, image_id, status):
    """Waits for an image to reach a given status.

    The client should have a show_image(image_id) method to get the image.
    The client should also have build_interval and build_timeout attributes.
    """
    show_image = client.show_image

    current_status = 'An unknown status'
    start = int(time.time())
    while int(time.time()) - start < client.build_timeout:
        image = show_image(image_id)
        # Compute image client returns response wrapped in 'image' element
        # which is not the case with Glance image client.
        if 'image' in image:
            image = image['image']

        current_status = image['status']
        if current_status == status:
            return
        if current_status.lower() == 'killed':
            raise exceptions.ImageKilledException(image_id=image_id,
                                                  status=status)
        if current_status.lower() == 'error':
            raise exceptions.AddImageException(image_id=image_id)

        time.sleep(client.build_interval)

    message = ('Image %(image_id)s failed to reach %(status)s state '
               '(current state %(current_status)s) within the required '
               'time (%(timeout)s s).' % {'image_id': image_id,
                                          'status': status,
                                          'current_status': current_status,
                                          'timeout': client.build_timeout})
    caller = test_utils.find_test_caller()
    if caller:
        message = '(%s) %s' % (caller, message)
    raise lib_exc.TimeoutException(message)


def wait_for_image_tasks_status(client, image_id, status):
    """Waits for an image tasks to reach a given status."""
    pending_tasks = []
    start = int(time.time())
    while int(time.time()) - start < client.build_timeout:
        tasks = client.show_image_tasks(image_id)['tasks']

        pending_tasks = [task for task in tasks if task['status'] != status]
        if not pending_tasks:
            return tasks
        time.sleep(client.build_interval)

    message = ('Image %(image_id)s tasks: %(pending_tasks)s '
               'failed to reach %(status)s state within the required '
               'time (%(timeout)s s).' % {'image_id': image_id,
                                          'pending_tasks': pending_tasks,
                                          'status': status,
                                          'timeout': client.build_timeout})
    caller = test_utils.find_test_caller()
    if caller:
        message = '(%s) %s' % (caller, message)
    raise lib_exc.TimeoutException(message)


def wait_for_tasks_status(client, task_id, status):
    start = int(time.time())
    while int(time.time()) - start < client.build_timeout:
        task = client.show_tasks(task_id)
        if task['status'] == status:
            return task
        time.sleep(client.build_interval)
    message = ('Task %(task_id)s tasks: '
               'failed to reach %(status)s state within the required '
               'time (%(timeout)s s).' % {'task_id': task_id,
                                          'status': status,
                                          'timeout': client.build_timeout})
    caller = test_utils.find_test_caller()
    if caller:
        message = '(%s) %s' % (caller, message)
    raise lib_exc.TimeoutException(message)


def wait_for_image_imported_to_stores(client, image_id, stores=None):
    """Waits for an image to be imported to all requested stores.

    Short circuits to fail if the serer reports failure of any store.
    If stores is None, just wait for status==active.

    The client should also have build_interval and build_timeout attributes.
    """

    exc_cls = lib_exc.TimeoutException
    start = int(time.time())

    # NOTE(danms): Don't wait for stores that are read-only as those
    # will never complete
    try:
        store_info = client.info_stores()['stores']
        stores = ','.join(sorted([
            store['id'] for store in store_info
            if store.get('read-only') != 'true' and
            (not stores or store['id'] in stores.split(','))]))
    except lib_exc.NotFound:
        # If multi-store is not enabled, then we can not resolve which
        # ones are read-only, and stores must have been passed as None
        # anyway for us to succeed. If not, then we should raise right
        # now and avoid waiting since we will never see the stores
        # appear.
        if stores is not None:
            raise lib_exc.TimeoutException(
                'Image service has no store support; '
                'cowardly refusing to wait for them.')

    while int(time.time()) - start < client.build_timeout:
        image = client.show_image(image_id)
        if image['status'] == 'active' and (stores is None or
                                            image['stores'] == stores):
            return
        if image.get('os_glance_failed_import'):
            exc_cls = lib_exc.OtherRestClientException
            break

        time.sleep(client.build_interval)

    message = ('Image %s failed to import on stores: %s' %
               (image_id, str(image.get('os_glance_failed_import'))))
    caller = test_utils.find_test_caller()
    if caller:
        message = '(%s) %s' % (caller, message)
    raise exc_cls(message)


def wait_for_image_copied_to_stores(client, image_id):
    """Waits for an image to be copied on all requested stores.

    The client should also have build_interval and build_timeout attributes.
    This return the list of stores where copy is failed.
    """

    start = int(time.time())
    store_left = []
    while int(time.time()) - start < client.build_timeout:
        image = client.show_image(image_id)
        store_left = image.get('os_glance_importing_to_stores')
        # NOTE(danms): If os_glance_importing_to_stores is None, then
        # we've raced with the startup of the task and should continue
        # to wait.
        if store_left is not None and not store_left:
            return image['os_glance_failed_import']
        if image['status'].lower() == 'killed':
            raise exceptions.ImageKilledException(image_id=image_id,
                                                  status=image['status'])

        time.sleep(client.build_interval)

    message = ('Image %s failed to finish the copy operation '
               'on stores: %s' % (image_id, str(store_left)))
    caller = test_utils.find_test_caller()
    if caller:
        message = '(%s) %s' % (caller, message)
    raise lib_exc.TimeoutException(message)


def wait_for_image_deleted_from_store(client, image, available_stores,
                                      image_store_deleted):
    """Waits for an image to be deleted from specific store.

    API will not allow deletion of the last location for an image.
    This return image if image deleted from store.
    """

    # Check if image have last store location
    if len(available_stores) == 1:
        exc_cls = lib_exc.OtherRestClientException
        message = ('Delete from last store location not allowed'
                   % (image, image_store_deleted))
        raise exc_cls(message)
    start = int(time.time())
    while int(time.time()) - start < client.build_timeout:
        image = client.show_image(image['id'])
        image_stores = image['stores'].split(",")
        if image_store_deleted not in image_stores:
            return
        time.sleep(client.build_interval)
    message = ('Failed to delete %s from requested store location: %s '
               'within the required time: (%s s)' %
               (image, image_store_deleted, client.build_timeout))
    caller = test_utils.find_test_caller()
    if caller:
        message = '(%s) %s' % (caller, message)
    raise exc_cls(message)


def wait_for_volume_resource_status(client, resource_id, status,
                                    server_id=None, servers_client=None):
    """Waits for a volume resource to reach a given status.

    This function is a common function for volume, snapshot and backup
    resources. The function extracts the name of the desired resource from
    the client class name of the resource.

    If server_id and servers_client are provided, dump the console for that
    server on failure.
    """
    resource_name = re.findall(
        r'(volume|group-snapshot|snapshot|backup|group)',
        client.resource_type)[-1].replace('-', '_')
    show_resource = getattr(client, 'show_' + resource_name)
    resource_status = show_resource(resource_id)[resource_name]['status']
    start = int(time.time())

    while resource_status != status:
        time.sleep(client.build_interval)
        resource_status = show_resource(resource_id)[
            '{}'.format(resource_name)]['status']
        if resource_status == 'error' and resource_status != status:
            raise exceptions.VolumeResourceBuildErrorException(
                resource_name=resource_name, resource_id=resource_id)
        if resource_name == 'volume' and resource_status == 'error_restoring':
            raise exceptions.VolumeRestoreErrorException(volume_id=resource_id)
        if resource_status == 'error_extending' and resource_status != status:
            raise exceptions.VolumeExtendErrorException(volume_id=resource_id)

        if int(time.time()) - start >= client.build_timeout:
            if server_id and servers_client:
                console_output = servers_client.get_console_output(
                    server_id)['output']
                LOG.debug('Console output for %s\nbody=\n%s',
                          server_id, console_output)
            message = ('%s %s failed to reach %s status (current %s) '
                       'within the required time (%s s).' %
                       (resource_name, resource_id, status, resource_status,
                        client.build_timeout))
            raise lib_exc.TimeoutException(message)
    LOG.info('%s %s reached %s after waiting for %f seconds',
             resource_name, resource_id, status, time.time() - start)


def wait_for_volume_attachment_create(client, volume_id, server_id):
    """Waits for a volume attachment to be created at a given volume."""
    start = int(time.time())
    while True:
        attachments = client.show_volume(volume_id)['volume']['attachments']
        found = [a for a in attachments if a['server_id'] == server_id]
        if found:
            LOG.info('Attachment %s created for volume %s to server %s after '
                     'waiting for %f seconds', found[0]['attachment_id'],
                     volume_id, server_id, time.time() - start)
            return found[0]
        time.sleep(client.build_interval)
        if int(time.time()) - start >= client.build_timeout:
            message = ('Failed to attach volume %s to server %s '
                       'within the required time (%s s).' %
                       (volume_id, server_id, client.build_timeout))
            raise lib_exc.TimeoutException(message)


def wait_for_volume_attachment_remove(client, volume_id, attachment_id):
    """Waits for a volume attachment to be removed from a given volume."""
    start = int(time.time())
    attachments = client.show_volume(volume_id)['volume']['attachments']
    while any(attachment_id == a['attachment_id'] for a in attachments):
        time.sleep(client.build_interval)
        if int(time.time()) - start >= client.build_timeout:
            message = ('Failed to remove attachment %s from volume %s '
                       'within the required time (%s s).' %
                       (attachment_id, volume_id, client.build_timeout))
            raise lib_exc.TimeoutException(message)
        attachments = client.show_volume(volume_id)['volume']['attachments']
    LOG.info('Attachment %s removed from volume %s after waiting for %f '
             'seconds', attachment_id, volume_id, time.time() - start)


def wait_for_volume_attachment_remove_from_server(
        client, server_id, volume_id):
    """Waits for a volume to be removed from a given server.

    This waiter checks the compute API if the volume attachment is removed.
    """
    start = int(time.time())

    try:
        volumes = client.list_volume_attachments(
            server_id)['volumeAttachments']
    except lib_exc.NotFound:
        # Ignore 404s on detach in case the server is deleted or the volume
        # is already detached.
        return

    while any(volume for volume in volumes if volume['volumeId'] == volume_id):
        time.sleep(client.build_interval)

        timed_out = int(time.time()) - start >= client.build_timeout
        if timed_out:
            console_output = client.get_console_output(server_id)['output']
            LOG.debug('Console output for %s\nbody=\n%s',
                      server_id, console_output)
            message = ('Volume %s failed to detach from server %s within '
                       'the required time (%s s) from the compute API '
                       'perspective' %
                       (volume_id, server_id, client.build_timeout))
            raise lib_exc.TimeoutException(message)
        try:
            volumes = client.list_volume_attachments(
                server_id)['volumeAttachments']
        except lib_exc.NotFound:
            # Ignore 404s on detach in case the server is deleted or the volume
            # is already detached.
            return
    return


def wait_for_volume_migration(client, volume_id, new_host):
    """Waits for a Volume to move to a new host."""
    body = client.show_volume(volume_id)['volume']
    host = body['os-vol-host-attr:host']
    migration_status = body['migration_status']
    start = int(time.time())

    # new_host is hostname@backend while current_host is hostname@backend#type
    while migration_status != 'success' or new_host not in host:
        time.sleep(client.build_interval)
        body = client.show_volume(volume_id)['volume']
        host = body['os-vol-host-attr:host']
        migration_status = body['migration_status']

        if migration_status == 'error':
            message = ('volume %s failed to migrate.' % (volume_id))
            raise lib_exc.TempestException(message)

        if int(time.time()) - start >= client.build_timeout:
            message = ('Volume %s failed to migrate to %s (current %s) '
                       'within the required time (%s s).' %
                       (volume_id, new_host, host, client.build_timeout))
            raise lib_exc.TimeoutException(message)


def wait_for_volume_retype(client, volume_id, new_volume_type):
    """Waits for a Volume to have a new volume type."""
    body = client.show_volume(volume_id)['volume']
    current_volume_type = body['volume_type']
    start = int(time.time())

    while current_volume_type != new_volume_type:
        time.sleep(client.build_interval)
        body = client.show_volume(volume_id)['volume']
        current_volume_type = body['volume_type']

        if int(time.time()) - start >= client.build_timeout:
            message = ('Volume %s failed to reach %s volume type (current %s) '
                       'within the required time (%s s).' %
                       (volume_id, new_volume_type, current_volume_type,
                        client.build_timeout))
            raise lib_exc.TimeoutException(message)


def wait_for_qos_operations(client, qos_id, operation, args=None):
    """Waits for a qos operations to be completed.

    NOTE : operation value is required for  wait_for_qos_operations()
    operation = 'qos-key' / 'disassociate' / 'disassociate-all'
    args = keys[] when operation = 'qos-key'
    args = volume-type-id disassociated when operation = 'disassociate'
    args = None when operation = 'disassociate-all'
    """
    start_time = int(time.time())
    while True:
        if operation == 'qos-key-unset':
            body = client.show_qos(qos_id)['qos_specs']
            if not any(key in body['specs'] for key in args):
                return
        elif operation == 'disassociate':
            body = client.show_association_qos(qos_id)['qos_associations']
            if not any(args in body[i]['id'] for i in range(0, len(body))):
                return
        elif operation == 'disassociate-all':
            body = client.show_association_qos(qos_id)['qos_associations']
            if not body:
                return
        else:
            msg = (" operation value is either not defined or incorrect.")
            raise lib_exc.UnprocessableEntity(msg)

        if int(time.time()) - start_time >= client.build_timeout:
            raise lib_exc.TimeoutException
        time.sleep(client.build_interval)


def wait_for_interface_status(client, server_id, port_id, status):
    """Waits for an interface to reach a given status."""
    body = (client.show_interface(server_id, port_id)
            ['interfaceAttachment'])
    interface_status = body['port_state']
    start = int(time.time())

    while(interface_status != status):
        time.sleep(client.build_interval)
        body = (client.show_interface(server_id, port_id)
                ['interfaceAttachment'])
        interface_status = body['port_state']

        timed_out = int(time.time()) - start >= client.build_timeout

        if interface_status != status and timed_out:
            message = ('Interface %s failed to reach %s status '
                       '(current %s) within the required time (%s s).' %
                       (port_id, status, interface_status,
                        client.build_timeout))
            raise lib_exc.TimeoutException(message)

    return body


def wait_for_interface_detach(client, server_id, port_id, detach_request_id):
    """Waits for an interface to be detached from a server."""
    def _get_detach_event_results():
        # NOTE(gibi): The obvious choice for this waiter would be to wait
        # until the interface disappears from the client.list_interfaces()
        # response. However that response is based on the binding status of the
        # port in Neutron. Nova deallocates the port resources _after the port
        # was  unbound in Neutron. This can cause that the naive waiter would
        # return before the port is fully deallocated. Wait instead of the
        # os-instance-action to succeed as that is recorded after both the
        # port is fully deallocated.
        events = client.show_instance_action(
            server_id, detach_request_id)['instanceAction'].get('events', [])
        return [
            event['result'] for event in events
            if event['event'] == 'compute_detach_interface'
        ]

    detach_event_results = _get_detach_event_results()

    start = int(time.time())

    while "Success" not in detach_event_results:
        time.sleep(client.build_interval)
        detach_event_results = _get_detach_event_results()
        if "Success" in detach_event_results:
            return client.show_instance_action(
                server_id, detach_request_id)['instanceAction']

        timed_out = int(time.time()) - start >= client.build_timeout
        if timed_out:
            message = ('Interface %s failed to detach from server %s within '
                       'the required time (%s s)' % (port_id, server_id,
                                                     client.build_timeout))
            raise lib_exc.TimeoutException(message)


def wait_for_server_floating_ip(servers_client, server, floating_ip,
                                wait_for_disassociate=False):
    """Wait for floating IP association or disassociation.

    :param servers_client: The servers client to use when querying the server's
    floating IPs.
    :param server: The server JSON dict on which to wait.
    :param floating_ip: The floating IP JSON dict on which to wait.
    :param wait_for_disassociate: Boolean indicating whether to wait for
    disassociation instead of association.
    """

    def _get_floating_ip_in_server_addresses(floating_ip, server):
        for addresses in server['addresses'].values():
            for address in addresses:
                if (
                    address['OS-EXT-IPS:type'] == 'floating' and
                    address['addr'] == floating_ip['floating_ip_address']
                ):
                    return address
        return None

    start_time = int(time.time())
    while True:
        server = servers_client.show_server(server['id'])['server']
        address = _get_floating_ip_in_server_addresses(floating_ip, server)
        if address is None and wait_for_disassociate:
            return None
        if not wait_for_disassociate and address:
            return address

        if int(time.time()) - start_time >= servers_client.build_timeout:
            if wait_for_disassociate:
                msg = ('Floating ip %s failed to disassociate from server %s '
                       'in time.' % (floating_ip, server['id']))
            else:
                msg = ('Floating ip %s failed to associate with server %s '
                       'in time.' % (floating_ip, server['id']))
            raise lib_exc.TimeoutException(msg)
        time.sleep(servers_client.build_interval)


def wait_for_ping(server_ip, timeout=30, interval=1):
    """Waits for an address to become pingable"""
    start_time = int(time.time())
    while int(time.time()) - start_time < timeout:
        response = os.system("ping -c 1 " + server_ip)
        if response == 0:
            return
        time.sleep(interval)
    raise lib_exc.TimeoutException()


def wait_for_port_status(client, port_id, status):
    """Wait for a port reach a certain status : ["BUILD" | "DOWN" | "ACTIVE"]
    :param client: The network client to use when querying the port's
    status
    :param status: A string to compare the current port status-to.
    :param port_id: The uuid of the port we would like queried for status.
    """
    start_time = time.time()
    while (time.time() - start_time <= client.build_timeout):
        result = client.show_port(port_id)
        if result['port']['status'].lower() == status.lower():
            return result
        time.sleep(client.build_interval)
    raise lib_exc.TimeoutException


def wait_for_server_ports_active(client, server_id, is_active, **kwargs):
    """Wait for all server ports to reach active status
    :param client: The network client to use when querying the port's status
    :param server_id: The uuid of the server's ports we need to verify.
    :param is_active: A function to call to the check port active status.
    :param kwargs: Additional arguments, if any, to pass to list_ports()
    """
    start_time = time.time()
    while (time.time() - start_time <= client.build_timeout):
        ports = client.list_ports(device_id=server_id, **kwargs)['ports']
        if all(is_active(port) for port in ports):
            LOG.debug("Server ID %s ports are all ACTIVE %s: ",
                      server_id, ports)
            return ports
        LOG.warning("Server ID %s has ports that are not ACTIVE, waiting "
                    "for state to change on all: %s", server_id, ports)
        time.sleep(client.build_interval)
    LOG.error("Server ID %s ports have failed to transition to ACTIVE, "
              "timing out: %s", server_id, ports)
    raise lib_exc.TimeoutException


def wait_for_ssh(ssh_client, timeout=30):
    """Waits for SSH connection to become usable"""
    start_time = int(time.time())
    while int(time.time()) - start_time < timeout:
        try:
            ssh_client.validate_authentication()
            return
        except lib_exc.SSHTimeout:
            pass
    raise lib_exc.TimeoutException()


def wait_for_caching(client, cache_client, image_id):
    """Waits until image is cached"""
    start = int(time.time())
    while int(time.time()) - start < client.build_timeout:
        caching = cache_client.list_cache()
        output = [image['image_id'] for image in caching['cached_images']]
        if output and image_id in output:
            return caching

        time.sleep(client.build_interval)

    message = ('Image %s failed to cache in time.' % image_id)
    caller = test_utils.find_test_caller()
    if caller:
        message = '(%s) %s' % (caller, message)
    raise lib_exc.TimeoutException(message)


def wait_for_object_create(object_client, container_name, object_name,
                           interval=1):
    """Waits for created object to become available"""
    start_time = time.time()
    while time.time() - start_time < object_client.build_timeout:
        try:
            return object_client.get_object(container_name, object_name)
        except lib_exc.NotFound:
            time.sleep(interval)
    message = ('Object %s failed to create within the required time (%s s).' %
               (object_name, object_client.build_timeout))
    raise lib_exc.TimeoutException(message)