Source code for kazoo.testing.harness

"""Kazoo testing harnesses"""

import logging
import os
import uuid
import unittest

from kazoo import python2atexit as atexit

from kazoo.client import KazooClient
from kazoo.exceptions import KazooException, NotEmptyError
from kazoo.protocol.states import (
from kazoo.testing.common import ZookeeperCluster
from kazoo.protocol.connection import _CONNECTION_DROP, _SESSION_EXPIRED

log = logging.getLogger(__name__)


def get_global_cluster():
    global CLUSTER
    if CLUSTER is None:
        ZK_HOME = os.environ.get("ZOOKEEPER_PATH")
        ZK_CLASSPATH = os.environ.get("ZOOKEEPER_CLASSPATH")
        ZK_PORT_OFFSET = int(os.environ.get("ZOOKEEPER_PORT_OFFSET", 20000))
        ZK_CLUSTER_SIZE = int(os.environ.get("ZOOKEEPER_CLUSTER_SIZE", 3))
        ZK_OBSERVER_START_ID = int(os.environ.get("ZOOKEEPER_OBSERVER_START_ID", -1))

        assert ZK_HOME or ZK_CLASSPATH, (
            "Either ZOOKEEPER_PATH or ZOOKEEPER_CLASSPATH environment "
            "variable must be defined.\n"
            "For deb package installations this is /usr/share/java")

        CLUSTER = ZookeeperCluster(
        atexit.register(lambda cluster: cluster.terminate(), CLUSTER)
    return CLUSTER

[docs]class KazooTestHarness(unittest.TestCase): """Harness for testing code that uses Kazoo This object can be used directly or as a mixin. It supports starting and stopping a complete ZooKeeper cluster locally and provides an API for simulating errors and expiring sessions. Example:: class MyTestCase(KazooTestHarness): def setUp(self): self.setup_zookeeper() # additional test setup def tearDown(self): self.teardown_zookeeper() def test_something(self): something_that_needs_a_kazoo_client(self.client) def test_something_else(self): something_that_needs_zk_servers(self.servers) """ def __init__(self, *args, **kw): super(KazooTestHarness, self).__init__(*args, **kw) self.client = None self._clients = [] @property def cluster(self): return get_global_cluster() @property def servers(self): return ",".join([s.address for s in self.cluster]) def _get_nonchroot_client(self): c = KazooClient(self.servers) self._clients.append(c) return c def _get_client(self, **kwargs): c = KazooClient(self.hosts, **kwargs) self._clients.append(c) return c def lose_connection(self, event_factory): """Force client to lose connection with server""" self.__break_connection(_CONNECTION_DROP, KazooState.SUSPENDED, event_factory) def expire_session(self, event_factory): """Force ZK to expire a client session""" self.__break_connection(_SESSION_EXPIRED, KazooState.LOST, event_factory) def setup_zookeeper(self, **client_options): """Create a ZK cluster and chrooted :class:`KazooClient` The cluster will only be created on the first invocation and won't be fully torn down until exit. """ do_start = False for s in self.cluster: if not s.running: do_start = True if do_start: self.cluster.start() namespace = "/kazootests" + uuid.uuid4().hex self.hosts = self.servers + namespace if 'timeout' not in client_options: client_options['timeout'] = 0.8 self.client = self._get_client(**client_options) self.client.start() self.client.ensure_path("/") def teardown_zookeeper(self): """Reset and cleanup the zookeeper cluster that was started.""" while self._clients: c = self._clients.pop() try: c.stop() except KazooException: log.exception("Failed stopping client %s", c) finally: c.close() self.client = None def __break_connection(self, break_event, expected_state, event_factory): """Break ZooKeeper connection using the specified event.""" lost = event_factory() safe = event_factory() def watch_loss(state): if state == expected_state: lost.set() elif lost.is_set() and state == KazooState.CONNECTED: safe.set() return True self.client.add_listener(watch_loss) self.client._call(break_event, None) lost.wait(5) if not lost.isSet(): raise Exception("Failed to get notified of broken connection.") safe.wait(15) if not safe.isSet(): raise Exception("Failed to see client reconnect.") self.client.retry(self.client.get_async, '/')
[docs]class KazooTestCase(KazooTestHarness): def setUp(self): self.setup_zookeeper() def tearDown(self): self.teardown_zookeeper()