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Add get methods to the driver-lib

This patch adds get methods to the driver-lib which allows provider
drivers to query for objects by ID.
In support of the get methods, this patch fixes a bug in the data
model to_dict() where it may not properly recurse the objects.
It also improves connecting to the driver agent sockets and adds a
timeout while waiting to receive data from the driver-agent.

Change-Id: Ia69d1f61571a1a65dee585037affb317999d7ade
Story: 2005870
Task: 33682
changes/27/665027/10
Michael Johnson 2 years ago
parent
commit
d700c00a90
8 changed files with 320 additions and 8 deletions
  1. +1
    -0
      lower-constraints.txt
  2. +1
    -0
      octavia_lib/api/drivers/data_models.py
  3. +152
    -1
      octavia_lib/api/drivers/driver_lib.py
  4. +43
    -5
      octavia_lib/api/drivers/exceptions.py
  5. +1
    -0
      octavia_lib/common/constants.py
  6. +110
    -2
      octavia_lib/tests/unit/api/drivers/test_driver_lib.py
  7. +11
    -0
      releasenotes/notes/Add-get-methods-to-driver-lib-dae3c217e7ac9e82.yaml
  8. +1
    -0
      requirements.txt

+ 1
- 0
lower-constraints.txt View File

@ -13,4 +13,5 @@ pylint==1.9.2
python-subunit==1.0.0
six==1.10.0
stestr==2.0.0
tenacity==5.0.2
testtools==2.2.0

+ 1
- 0
octavia_lib/api/drivers/data_models.py View File

@ -51,6 +51,7 @@ class BaseDataModel(object):
elif isinstance(getattr(self, attr), BaseDataModel):
if type(self) not in calling_classes:
ret[attr] = value.to_dict(
recurse=recurse,
render_unsets=render_unsets,
calling_classes=calling_classes + [type(self)])
else:


+ 152
- 1
octavia_lib/api/drivers/driver_lib.py View File

@ -12,40 +12,77 @@
# License for the specific language governing permissions and limitations
# under the License.
import os
import socket
import time
from oslo_serialization import jsonutils
import tenacity
from octavia_lib.api.drivers import data_models
from octavia_lib.api.drivers import exceptions as driver_exceptions
from octavia_lib.common import constants
DEFAULT_STATUS_SOCKET = '/var/run/octavia/status.sock'
DEFAULT_STATS_SOCKET = '/var/run/octavia/stats.sock'
DEFAULT_GET_SOCKET = '/var/run/octavia/get.sock'
SOCKET_TIMEOUT = 5
DRIVER_AGENT_TIMEOUT = 30
class DriverLibrary(object):
@tenacity.retry(
stop=tenacity.stop_after_attempt(30), reraise=True,
wait=tenacity.wait_exponential(multiplier=1, min=1, max=5),
retry=tenacity.retry_if_exception_type(
driver_exceptions.DriverAgentNotFound))
def _check_for_socket_ready(self, socket):
if not os.path.exists(socket):
raise driver_exceptions.DriverAgentNotFound(
fault_string=('Unable to open the driver agent '
'socket: {}'.format(socket)))
def __init__(self, status_socket=DEFAULT_STATUS_SOCKET,
stats_socket=DEFAULT_STATS_SOCKET, **kwargs):
stats_socket=DEFAULT_STATS_SOCKET,
get_socket=DEFAULT_GET_SOCKET, **kwargs):
self.status_socket = status_socket
self.stats_socket = stats_socket
self.get_socket = get_socket
self._check_for_socket_ready(status_socket)
self._check_for_socket_ready(stats_socket)
self._check_for_socket_ready(get_socket)
super(DriverLibrary, self).__init__(**kwargs)
def _recv(self, sock):
size_str = b''
char = sock.recv(1)
begin = time.time()
while char != b'\n':
size_str += char
char = sock.recv(1)
if time.time() - begin > DRIVER_AGENT_TIMEOUT:
raise driver_exceptions.DriverAgentTimeout(
fault_string=('The driver agent did not respond in {} '
'seconds.'.format(DRIVER_AGENT_TIMEOUT)))
# Give the CPU a break from polling
time.sleep(0.01)
payload_size = int(size_str)
mv_buffer = memoryview(bytearray(payload_size))
next_offset = 0
begin = time.time()
while payload_size - next_offset > 0:
recv_size = sock.recv_into(mv_buffer[next_offset:],
payload_size - next_offset)
next_offset += recv_size
if time.time() - begin > DRIVER_AGENT_TIMEOUT:
raise driver_exceptions.DriverAgentTimeout(
fault_string=('The driver agent did not respond in {} '
'seconds.'.format(DRIVER_AGENT_TIMEOUT)))
# Give the CPU a break from polling
time.sleep(0.01)
return jsonutils.loads(mv_buffer.tobytes())
def _send(self, socket_path, data):
@ -114,3 +151,117 @@ class DriverLibrary(object):
stats_object=response.pop(constants.STATS_OBJECT, None),
stats_object_id=response.pop(constants.STATS_OBJECT_ID, None),
stats_record=response.pop(constants.STATS_RECORD, None))
def _get_resource(self, resource, id):
try:
return self._send(self.get_socket, {constants.OBJECT: resource,
constants.ID: id})
except driver_exceptions.DriverAgentTimeout:
raise
except Exception:
raise driver_exceptions.DriverError()
def get_loadbalancer(self, loadbalancer_id):
"""Get a load balancer object.
:param loadbalancer_id: The load balancer ID to lookup.
:type loadbalancer_id: UUID string
:raises DriverAgentTimeout: The driver agent did not respond
inside the timeout.
:raises DriverError: An unexpected error occurred.
:returns: A LoadBalancer object or None if not found.
"""
data = self._get_resource(constants.LOADBALANCERS, loadbalancer_id)
if data:
return data_models.LoadBalancer.from_dict(data)
return None
def get_listener(self, listener_id):
"""Get a listener object.
:param listener_id: The listener ID to lookup.
:type listener_id: UUID string
:raises DriverAgentTimeout: The driver agent did not respond
inside the timeout.
:raises DriverError: An unexpected error occurred.
:returns: A Listener object or None if not found.
"""
data = self._get_resource(constants.LISTENERS, listener_id)
if data:
return data_models.Listener.from_dict(data)
return None
def get_pool(self, pool_id):
"""Get a pool object.
:param pool_id: The pool ID to lookup.
:type pool_id: UUID string
:raises DriverAgentTimeout: The driver agent did not respond
inside the timeout.
:raises DriverError: An unexpected error occurred.
:returns: A Pool object or None if not found.
"""
data = self._get_resource(constants.POOLS, pool_id)
if data:
return data_models.Pool.from_dict(data)
return None
def get_healthmonitor(self, healthmonitor_id):
"""Get a health monitor object.
:param healthmonitor_id: The health monitor ID to lookup.
:type healthmonitor_id: UUID string
:raises DriverAgentTimeout: The driver agent did not respond
inside the timeout.
:raises DriverError: An unexpected error occurred.
:returns: A HealthMonitor object or None if not found.
"""
data = self._get_resource(constants.HEALTHMONITORS, healthmonitor_id)
if data:
return data_models.HealthMonitor.from_dict(data)
return None
def get_member(self, member_id):
"""Get a member object.
:param member_id: The member ID to lookup.
:type member_id: UUID string
:raises DriverAgentTimeout: The driver agent did not respond
inside the timeout.
:raises DriverError: An unexpected error occurred.
:returns: A Member object or None if not found.
"""
data = self._get_resource(constants.MEMBERS, member_id)
if data:
return data_models.Member.from_dict(data)
return None
def get_l7policy(self, l7policy_id):
"""Get a L7 policy object.
:param l7policy_id: The L7 policy ID to lookup.
:type l7policy_id: UUID string
:raises DriverAgentTimeout: The driver agent did not respond
inside the timeout.
:raises DriverError: An unexpected error occurred.
:returns: A L7Policy object or None if not found.
"""
data = self._get_resource(constants.L7POLICIES, l7policy_id)
if data:
return data_models.L7Policy.from_dict(data)
return None
def get_l7rule(self, l7rule_id):
"""Get a L7 rule object.
:param l7rule_id: The L7 rule ID to lookup.
:type l7rule_id: UUID string
:raises DriverAgentTimeout: The driver agent did not respond
inside the timeout.
:raises DriverError: An unexpected error occurred.
:returns: A L7Rule object or None if not found.
"""
data = self._get_resource(constants.L7RULES, l7rule_id)
if data:
return data_models.L7Rule.from_dict(data)
return None

+ 43
- 5
octavia_lib/api/drivers/exceptions.py View File

@ -38,7 +38,8 @@ class DriverError(Exception):
self.user_fault_string)
self.operator_fault_string = kwargs.pop('operator_fault_string',
self.operator_fault_string)
super(DriverError, self).__init__(*args, **kwargs)
super(DriverError, self).__init__(self.user_fault_string,
*args, **kwargs)
class NotImplementedError(Exception):
@ -59,7 +60,8 @@ class NotImplementedError(Exception):
self.user_fault_string)
self.operator_fault_string = kwargs.pop('operator_fault_string',
self.operator_fault_string)
super(NotImplementedError, self).__init__(*args, **kwargs)
super(NotImplementedError, self).__init__(self.user_fault_string,
*args, **kwargs)
class UnsupportedOptionError(Exception):
@ -88,7 +90,8 @@ class UnsupportedOptionError(Exception):
self.user_fault_string)
self.operator_fault_string = kwargs.pop('operator_fault_string',
self.operator_fault_string)
super(UnsupportedOptionError, self).__init__(*args, **kwargs)
super(UnsupportedOptionError, self).__init__(self.user_fault_string,
*args, **kwargs)
class UpdateStatusError(Exception):
@ -116,7 +119,8 @@ class UpdateStatusError(Exception):
self.status_object_id = kwargs.pop('status_object_id', None)
self.status_record = kwargs.pop('status_record', None)
super(UpdateStatusError, self).__init__(*args, **kwargs)
super(UpdateStatusError, self).__init__(self.fault_string,
*args, **kwargs)
class UpdateStatisticsError(Exception):
@ -145,4 +149,38 @@ class UpdateStatisticsError(Exception):
self.stats_object_id = kwargs.pop('stats_object_id', None)
self.stats_record = kwargs.pop('stats_record', None)
super(UpdateStatisticsError, self).__init__(*args, **kwargs)
super(UpdateStatisticsError, self).__init__(self.fault_string,
*args, **kwargs)
class DriverAgentNotFound(Exception):
"""Exception raised when the driver agent cannot be reached.
Each exception will include a message field that describes the
error.
:param fault_string: String describing the fault.
:type fault_string: string
"""
fault_string = _("The driver-agent process was not found or not ready.")
def __init__(self, *args, **kwargs):
self.fault_string = kwargs.pop('fault_string', self.fault_string)
super(DriverAgentNotFound, self).__init__(self.fault_string,
*args, **kwargs)
class DriverAgentTimeout(Exception):
"""Exception raised when the driver agent does not respond.
Raised when communication with the driver agent times out.
Each exception will include a message field that describes the
error.
:param fault_string: String describing the fault.
:type fault_string: string
"""
fault_string = _("The driver-agent timeout.")
def __init__(self, *args, **kwargs):
self.fault_string = kwargs.pop('fault_string', self.fault_string)
super(DriverAgentTimeout, self).__init__(self.fault_string,
*args, **kwargs)

+ 1
- 0
octavia_lib/common/constants.py View File

@ -34,6 +34,7 @@ MEMBERS = 'members'
L7POLICIES = 'l7policies'
L7RULES = 'l7rules'
FLAVOR = 'flavor'
OBJECT = 'object'
# ID fields
ID = 'id'


+ 110
- 2
octavia_lib/tests/unit/api/drivers/test_driver_lib.py View File

@ -16,19 +16,37 @@ import mock
from octavia_lib.api.drivers import driver_lib
from octavia_lib.api.drivers import exceptions as driver_exceptions
from octavia_lib.common import constants
from octavia_lib.tests.unit import base
class TestDriverLib(base.TestCase):
def setUp(self):
@mock.patch('octavia_lib.api.drivers.driver_lib.DriverLibrary.'
'_check_for_socket_ready')
def setUp(self, mock_check_ready):
self.driver_lib = driver_lib.DriverLibrary()
super(TestDriverLib, self).setUp()
@mock.patch('octavia_lib.api.drivers.driver_lib.DriverLibrary.'
'_check_for_socket_ready.retry.sleep')
@mock.patch('os.path.exists')
def test_check_for_socket_ready(self, mock_path_exists, mock_sleep):
mock_path_exists.return_value = True
# should not raise an exception
self.driver_lib._check_for_socket_ready('bogus')
mock_path_exists.return_value = False
self.assertRaises(driver_exceptions.DriverAgentNotFound,
self.driver_lib._check_for_socket_ready,
'bogus')
@mock.patch('six.moves.builtins.memoryview')
def test_recv(self, mock_memoryview):
mock_socket = mock.MagicMock()
mock_socket.recv.side_effect = [b'1', b'\n']
mock_socket.recv.side_effect = [b'1', b'\n', b'2', b'\n', b'3', b'\n']
mock_socket.recv_into.return_value = 1
mv_mock = mock.MagicMock()
mock_memoryview.return_value = mv_mock
@ -43,6 +61,17 @@ class TestDriverLib(base.TestCase):
mv_mock.__getitem__(), 1)
self.assertEqual('test data', response)
# Test size recv timeout
with mock.patch('octavia_lib.api.drivers.driver_lib.'
'time') as mock_time:
mock_time.time.side_effect = [0, 1000, 0, 0, 0, 0, 1000]
self.assertRaises(driver_exceptions.DriverAgentTimeout,
self.driver_lib._recv, mock_socket)
# Test payload recv timeout
self.assertRaises(driver_exceptions.DriverAgentTimeout,
self.driver_lib._recv, mock_socket)
@mock.patch('octavia_lib.api.drivers.driver_lib.DriverLibrary._recv')
def test_send(self, mock_recv):
mock_socket = mock.MagicMock()
@ -105,3 +134,82 @@ class TestDriverLib(base.TestCase):
self.assertRaises(driver_exceptions.UpdateStatisticsError,
self.driver_lib.update_listener_statistics,
'fake_stats')
@mock.patch('octavia_lib.api.drivers.driver_lib.DriverLibrary._send')
def test_get_resource(self, mock_send):
fake_resource = 'fake resource'
fake_id = 'fake id'
mock_send.side_effect = ['some result',
driver_exceptions.DriverAgentTimeout,
Exception('boom')]
result = self.driver_lib._get_resource(fake_resource, fake_id)
data = {constants.OBJECT: fake_resource, constants.ID: fake_id}
mock_send.assert_called_once_with('/var/run/octavia/get.sock', data)
self.assertEqual('some result', result)
# Test with driver_exceptions.DriverAgentTimeout
self.assertRaises(driver_exceptions.DriverAgentTimeout,
self.driver_lib._get_resource,
fake_resource, fake_id)
# Test with random exception
self.assertRaises(driver_exceptions.DriverError,
self.driver_lib._get_resource,
fake_resource, fake_id)
@mock.patch('octavia_lib.api.drivers.driver_lib.DriverLibrary.'
'_get_resource')
def _test_get_object(self, get_method, name, mock_from_dict,
mock_get_resource):
mock_get_resource.side_effect = ['some data', None]
mock_from_dict.return_value = 'object'
result = get_method('fake id')
mock_get_resource.assert_called_once_with(name, 'fake id')
mock_from_dict.assert_called_once_with('some data')
self.assertEqual('object', result)
# Test not found
result = get_method('fake id')
self.assertIsNone(result)
@mock.patch('octavia_lib.api.drivers.data_models.LoadBalancer.from_dict')
def test_get_loadbalancer(self, mock_from_dict):
self._test_get_object(self.driver_lib.get_loadbalancer,
constants.LOADBALANCERS, mock_from_dict)
@mock.patch('octavia_lib.api.drivers.data_models.Listener.from_dict')
def test_get_listener(self, mock_from_dict):
self._test_get_object(self.driver_lib.get_listener,
constants.LISTENERS, mock_from_dict)
@mock.patch('octavia_lib.api.drivers.data_models.Pool.from_dict')
def test_get_pool(self, mock_from_dict):
self._test_get_object(self.driver_lib.get_pool,
constants.POOLS, mock_from_dict)
@mock.patch('octavia_lib.api.drivers.data_models.HealthMonitor.from_dict')
def test_get_healthmonitor(self, mock_from_dict):
self._test_get_object(self.driver_lib.get_healthmonitor,
constants.HEALTHMONITORS, mock_from_dict)
@mock.patch('octavia_lib.api.drivers.data_models.Member.from_dict')
def test_get_member(self, mock_from_dict):
self._test_get_object(self.driver_lib.get_member,
constants.MEMBERS, mock_from_dict)
@mock.patch('octavia_lib.api.drivers.data_models.L7Policy.from_dict')
def test_get_l7policy(self, mock_from_dict):
self._test_get_object(self.driver_lib.get_l7policy,
constants.L7POLICIES, mock_from_dict)
@mock.patch('octavia_lib.api.drivers.data_models.L7Rule.from_dict')
def test_get_l7rule(self, mock_from_dict):
self._test_get_object(self.driver_lib.get_l7rule,
constants.L7RULES, mock_from_dict)

+ 11
- 0
releasenotes/notes/Add-get-methods-to-driver-lib-dae3c217e7ac9e82.yaml View File

@ -0,0 +1,11 @@
---
features:
- |
The driver-lib now provides "get" methods for drivers to be able to
query for objects by id. For example, get_loadbalancer(loadbalancer_id).
fixes:
- Improved the driver_lib connecting to the driver-agent sockets.
- Fixed a bug where the data model to_dict() may not recurse properly.
- |
Message receiving for the driver_lib will timeout after no response
from the driver-agent.

+ 1
- 0
requirements.txt View File

@ -7,3 +7,4 @@ oslo.log>=3.36.0 # Apache-2.0
oslo.serialization>=2.28.1 # Apache-2.0
pbr!=2.1.0,>=2.0.0 # Apache-2.0
six>=1.10.0 # MIT
tenacity>=5.0.2 # Apache-2.0

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