def zk_main_02():
url = '127.0.0.1:2181'
zk_test_node = '/zk_test_02'
zkc = KazooClient(hosts=url, timeout=3)
zkc.start()
print('\npid=%d, zookeeper version: %s' %
(os.getpid(), zkc.server_version()))
try:
# ephemeral=False: cannot create child for ephemeral node
ret_path = zkc.create(path=zk_test_node,
value=b'zk_test_02_init',
ephemeral=False)
print('\ncreate a zk test node:', ret_path)
time.sleep(1)
zk_watcher = zkWatcher(url, zk_test_node)
p = multiprocessing.Process(target=zk_watcher.exec)
p.start()
time.sleep(1)
zk_test_02(zkc, zk_test_node)
if p is not None:
p.join(timeout=8)
if p.is_alive():
print('pid=%d is pending, and kill!' % p.pid)
p.kill()
finally:
if zkc.exists(zk_test_node, watch=None):
zkc.delete(zk_test_node, recursive=True)
# close zk session, and all ephemeral nodes will be removed
zkc.stop()
def run(args, helpers):
version = None
if KazooClient is None:
logging.warning(
"Skipping zookeper discovery as Kazoo python library is absent")
else:
try:
zk = KazooClient(hosts="%s:%d" % (args.ip, args.port),
read_only=True)
zk.start()
version = zk.server_version()
logging.info("Detected Zookeeper version: %s" %
('.'.join(str(i) for i in version)))
except Exception:
logging.exception(
"Zookeeper might not be running a client listener on this port"
)
return (version)
def exec(self):
zkc = KazooClient(hosts=self._url, timeout=3)
zkc.start()
print('\npid=%d, zookeeper version: %s' %
(os.getpid(), zkc.server_version()))
try:
self._list_ori = zkc.get_children(self._zk_node)
print('\nattach data and child watch')
# watch func trigger for each change
DataWatch(client=zkc, path=self._zk_node, func=self._data_change)
ChildrenWatch(client=zkc,
path=self._zk_node,
func=self._child_change)
print('\nzk watch is running ...')
time.sleep(6)
finally:
if zkc is not None:
zkc.stop()
def run(zk_host):
client = KazooClient(zk_host)
client.start(timeout=15)
zk_server_version = client.server_version()
client.add_listener()
print 'Server Version: {0}'.format(zk_server_version)
queue = Queue()
queue.enqueue('/')
while queue.size() > 0:
path = queue.dequeue()
path_node = client.get(path)
print '[{0}] {1}'.format(path_node[1].created, path)
path_children = client.get_children(path)
for child in path_children:
queue.enqueue(path + child + '/')
client.stop()
def zk_test_01(url, test_node):
# if run in multi process, should init a new zk client.
zkc = KazooClient(hosts=url, timeout=3)
zkc.start()
print('\npid=%d, zookeeper version: %s' %
(os.getpid(), zkc.server_version()))
try:
stat = zkc.set(test_node, b'zk_test_01_new_1')
print('\nzk test node updated, and stat version:', stat.version)
time.sleep(2)
stat = zkc.set(test_node, b'zk_test_01_new_2')
print('\nzk test node updated, and stat version:', stat.version)
time.sleep(1)
data, stat = zkc.get(test_node, watch=None)
print('\nzk node stat:')
print('\tnode data="%s", length=%d' % (data, stat.dataLength))
print('\tnode stat version:', stat.version)
print()
finally:
if zkc is not None:
zkc.stop()
class ZookeeperServiceRegistry(BaseServiceRegistry):
def __init__(self, hosts=DEFAULT_HOSTS, chroot=DEFAULT_CHROOT):
super(ZookeeperServiceRegistry, self).__init__()
self.chroot = chroot
self.client = KazooClient(
hosts=hosts,
handler=SequentialGeventHandler(),
)
self.client.add_listener(self.on_kazoo_state_change)
self.start_count = 0
@classmethod
def from_config(cls, config, **kwargs):
return cls(hosts=config.get('hosts', DEFAULT_HOSTS),
chroot=config.get('chroot', DEFAULT_CHROOT),
**kwargs)
def on_start(self, timeout=10):
self.start_count += 1
if self.start_count > 1:
return
started = self.client.start_async()
started.wait(timeout=timeout)
if not self.client.connected:
raise RuntimeError('could not connect to zookeeper')
logger.debug('connected to zookeeper (version=%s)',
'.'.join(map(str, self.client.server_version())))
def on_stop(self):
self.start_count -= 1
if self.start_count != 0:
return
self.client.stop()
def on_kazoo_state_change(self, state):
logger.info('kazoo connection state changed to %s', state)
def on_service_type_watch(self, service, event):
try:
if event.type == EventType.CHILD:
# FIXME: figure out proper retry strategy
self.client.retry(self.lookup, service.container, service)
except Exception:
logger.exception('error in service type watcher')
def on_service_watch(self, service, event):
try:
prefix, service_type, identity = event.path.rsplit('/', 2)
if event.type == EventType.DELETED:
service.remove(identity)
except Exception:
logger.exception('error in service watcher')
def _get_service_znode(self, service, service_type, identity):
path = self._get_zk_path(service_type, identity)
result = self.client.get_async(path,
watch=functools.partial(
self.on_service_watch, service))
value, znode = result.get()
items = six.iteritems(json.loads(value.decode('utf-8')))
return {str(k): str(v) for k, v in items}
def discover(self, container):
result = self.client.get_children_async(path='%s/services' %
self.chroot, )
return list(result.get())
def lookup(self, container, service, watch=True, timeout=1):
def child_watch(event):
print(event)
service_type = service.service_type
result = self.client.get_children_async(
path='%s/services/%s' % (self.chroot, service_type),
watch=functools.partial(self.on_service_type_watch, service),
)
try:
names = result.get(timeout=timeout)
except NoNodeError:
raise LookupFailure(None,
"failed to resolve %s" % service.service_type)
logger.info("lookup %s %r", service_type, names)
identities = set(service.identities())
for name in names:
kwargs = self._get_service_znode(service, service_type, name)
identity = kwargs.pop('identity')
service.update(identity, **kwargs)
try:
identities.remove(identity)
except KeyError:
pass
for identity in identities:
service.remove(identity)
return service
def _get_zk_path(self, service_type, identity):
return '%s/services/%s/%s' % (self.chroot, service_type, identity)
def register(self, container, service_type, timeout=1):
path = self._get_zk_path(service_type, container.identity)
value = json.dumps({
'endpoint': container.endpoint,
'identity': container.identity,
'log_endpoint': container.log_endpoint,
})
result = self.client.create_async(path,
value.encode('utf-8'),
ephemeral=True,
makepath=True)
# FIXME: result.set_exception(RegistrationFailure())
result.get(timeout=timeout)
def unregister(self, container, service_type, timeout=1):
path = self._get_zk_path(service_type, container.identity)
result = self.client.delete_async(path)
result.set_exception(RegistrationFailure())
result.get(timeout=timeout)
class ZookeeperWatcher(object):
zoo_client = None # The KazooClient to manage the config
point_path = None # Zookeeper path to pointed to file
pointed_at_expired = None # is True when the assignment has been set to
# None but we cannot remove the config listener
valid_handler = None # the function to call when the validity changes
config_handler = None # the function to call when the config changes
error_handler = None # the function to call when an error occurs in reading
valid_file = False # the current state of the ConfigWatcher with ZK
do_not_restart = False # used when closing via ^C
old_data = '' # The current file contents, to see if a change occurred
old_pointed = '' # the current pointed path, to see if change occurred
INVALID_PATH = "Invalid pointer path"
INVALID_GET = "Invalid get on file path"
BAD_CONNECTION = "Connection interrupted with Zookeeper, re-establishing"
def __init__(self, hosts, filepath, valid_handler=None,
config_handler=None, error_handler=None, pointer=False,
ensure=False, valid_init=True):
'''
Zookeeper file watcher, used to tell a program their zookeeper file has
changed. Can be used to watch a single file, or both a file and path of
its contents. Manages all connections, drops, reconnections for you.
@param hosts: The zookeeper hosts to use
@param filepath: The full path to the file to watch
@param valid_handler: The method to call for a 'is valid' state change
@param config_handler: The method to call when a content change occurs
@param error_handler: The method to call when an error occurs
@param pointer: Set to true if the file contents are actually a path to
another zookeeper file, where the real config resides
@param ensure: Set to true for the ZooWatcher to create the watched file
@param valid_init: Ensure the client can connect to Zookeeper first try
Ex 1. /stuff/A: "stuff I care about"
Ex 2. /stuff/A: "/other/stuff", /other/stuff: "contents I care about"
- in Ex 2 you care about /other/stuff contents
but are only aware of your assignment /stuff/A
You can use this class as any combination of event driven or polling.
Polling:
In the main loop of your program, check if is_valid() is
True, otherwise clear your contents as there is some ZK error.
Event:
You will be notified via the various handlers when content changes.
'''
self.hosts = hosts
self.my_file = filepath
self.pointer = pointer
self.ensure = ensure
self.valid_handler = valid_handler
self.config_handler = config_handler
self.error_handler = error_handler
if valid_init:
# this will throw an exception if it can't start right away
self.zoo_client = KazooClient(hosts=self.hosts)
self.zoo_client.start()
self.threaded_start(no_init=True)
def threaded_start(self, no_init=False):
'''
Spawns a worker thread to set up the zookeeper connection
'''
thread = Thread(target=self.init_connections, kwargs={
'no_init': no_init})
thread.setDaemon(True)
thread.start()
thread.join()
def init_connections(self, no_init=False):
'''
Sets up the initial Kazoo Client and watches
'''
success = False
self.set_valid(False)
if not no_init:
if self.zoo_client:
self.zoo_client.remove_listener(self.state_listener)
self.old_data = ''
self.old_pointed = ''
while not success:
try:
if self.zoo_client is None:
self.zoo_client = KazooClient(hosts=self.hosts)
self.zoo_client.start()
else:
# self.zoo_client.stop()
self.zoo_client._connection.connection_stopped.set()
self.zoo_client.close()
self.zoo_client = KazooClient(hosts=self.hosts)
self.zoo_client.start()
except Exception as e:
log.error("ZKWatcher Exception: " + e.message)
sleep(1)
continue
self.setup()
success = self.update_file(self.my_file)
sleep(5)
else:
self.setup()
self.update_file(self.my_file)
def setup(self):
'''
Ensures the path to the watched file exists and we have a state
listener
'''
self.zoo_client.add_listener(self.state_listener)
if self.ensure:
self.zoo_client.ensure_path(self.my_file)
def state_listener(self, state):
'''
Restarts the session if we get anything besides CONNECTED
'''
if state == KazooState.SUSPENDED:
self.set_valid(False)
self.call_error(self.BAD_CONNECTION)
elif state == KazooState.LOST and not self.do_not_restart:
self.threaded_start()
elif state == KazooState.CONNECTED:
# This is going to throw a SUSPENDED kazoo error
# which will cause the sessions to be wiped and re established.
# Used b/c of massive connection pool issues
self.zoo_client.stop()
def is_valid(self):
'''
@return: True if the currently watch file is valid
'''
return self.valid_file
def ping(self):
'''
Simple command to test if the zookeeper session is able to connect
at this very moment
'''
try:
# dummy ping to ensure we are still connected
self.zoo_client.server_version()
return True
except KazooException:
return False
def close(self, kill_restart=True):
'''
Use when you would like to close everything down
@param kill_restart= Prevent kazoo restarting from occurring
'''
self.do_not_restart = kill_restart
self.zoo_client.stop()
self.zoo_client.close()
def get_file_contents(self, pointer=False):
'''
Gets any file contents you care about. Defaults to the main file
@param pointer: The the contents of the file pointer, not the pointed
at file
@return: A string of the contents
'''
if self.pointer:
if pointer:
return self.old_pointed
else:
return self.old_data
else:
return self.old_data
def watch_file(self, event):
'''
Fired when changes made to the file
'''
if not self.update_file(self.my_file):
self.threaded_start()
def update_file(self, path):
'''
Updates the file watcher and calls the appropriate method for results
@return: False if we need to keep trying the connection
'''
try:
# grab the file
result, stat = self.zoo_client.get(path, watch=self.watch_file)
except ZookeeperError:
self.set_valid(False)
self.call_error(self.INVALID_GET)
return False
if self.pointer:
if result is not None and len(result) > 0:
self.pointed_at_expired = False
# file is a pointer, go update and watch other file
self.point_path = result
if self.compare_pointer(result):
self.update_pointed()
else:
self.pointed_at_expired = True
self.old_pointed = ''
self.old_data = ''
self.set_valid(False)
self.call_error(self.INVALID_PATH)
else:
# file is not a pointer, return contents
if self.compare_data(result):
self.call_config(result)
self.set_valid(True)
return True
def watch_pointed(self, event):
'''
Fired when changes made to pointed file
'''
self.update_pointed()
def update_pointed(self):
'''
Grabs the latest file contents based on the pointer uri
'''
# only grab file if our pointer is still good (not None)
if not self.pointed_at_expired:
try:
conf_string, stat2 = self.zoo_client.get(self.point_path,
watch=self.watch_pointed)
except ZookeeperError:
self.old_data = ''
self.set_valid(False)
self.pointed_at_expired = True
self.call_error(self.INVALID_PATH)
return
if self.compare_data(conf_string):
self.call_config(conf_string)
self.set_valid(True)
def set_valid(self, boolean):
'''
Sets the state and calls the change if needed
@param bool: The state (true or false)
'''
old_state = self.is_valid()
self.valid_file = boolean
if old_state != self.valid_file:
self.call_valid(self.valid_file)
def call_valid(self, state):
'''
Calls the valid change function passed in
@param valid_state: The new config
'''
if self.valid_handler is not None:
self.valid_handler(self.is_valid())
def call_config(self, new_config):
'''
Calls the config function passed in
@param new_config: The new config
'''
if self.config_handler is not None:
self.config_handler(new_config)
def call_error(self, message):
'''
Calls the error function passed in
@param message: The message to throw
'''
if self.error_handler is not None:
self.error_handler(message)
def compare_data(self, data):
'''
Compares the string data
@return: True if the data is different
'''
if self.old_data != data:
self.old_data = data
return True
return False
def compare_pointer(self, data):
'''
Compares the string data
@return: True if the data is different
'''
if self.old_pointed != data:
self.old_pointed = data
return True
return False
class ZookeeperWatcher(object):
zoo_client = None # The KazooClient to manage the config
point_path = None # Zookeeper path to pointed to file
pointed_at_expired = None # is True when the assignment has been set to
# None but we cannot remove the config listener
valid_handler = None # the function to call when the validity changes
config_handler = None # the function to call when the config changes
error_handler = None # the function to call when an error occurs in reading
valid_file = False # the current state of the ConfigWatcher with ZK
do_not_restart = False # used when closing via ^C
old_data = '' # The current file contents, to see if a change occurred
old_pointed = '' # the current pointed path, to see if change occurred
INVALID_PATH = "Invalid pointer path"
INVALID_GET = "Invalid get on file path"
BAD_CONNECTION = "Connection interrupted with Zookeeper, re-establishing"
def __init__(self,
hosts,
filepath,
valid_handler=None,
config_handler=None,
error_handler=None,
pointer=False,
ensure=False,
valid_init=True):
'''
Zookeeper file watcher, used to tell a program their zookeeper file has
changed. Can be used to watch a single file, or both a file and path of
its contents. Manages all connections, drops, reconnections for you.
@param hosts: The zookeeper hosts to use
@param filepath: The full path to the file to watch
@param valid_handler: The method to call for a 'is valid' state change
@param config_handler: The method to call when a content change occurs
@param error_handler: The method to call when an error occurs
@param pointer: Set to true if the file contents are actually a path to
another zookeeper file, where the real config resides
@param ensure: Set to true for the ZooWatcher to create the watched file
@param valid_init: Ensure the client can connect to Zookeeper first try
Ex 1. /stuff/A: "stuff I care about"
Ex 2. /stuff/A: "/other/stuff", /other/stuff: "contents I care about"
- in Ex 2 you care about /other/stuff contents
but are only aware of your assignment /stuff/A
You can use this class as any combination of event driven or polling.
Polling:
In the main loop of your program, check if is_valid() is
True, otherwise clear your contents as there is some ZK error.
Event:
You will be notified via the various handlers when content changes.
'''
self.hosts = hosts
self.my_file = filepath
self.pointer = pointer
self.ensure = ensure
self.valid_handler = valid_handler
self.config_handler = config_handler
self.error_handler = error_handler
if valid_init:
# this will throw an exception if it can't start right away
self.zoo_client = KazooClient(hosts=self.hosts)
self.zoo_client.start()
self.threaded_start(no_init=True)
def threaded_start(self, no_init=False):
'''
Spawns a worker thread to set up the zookeeper connection
'''
thread = Thread(target=self.init_connections,
kwargs={'no_init': no_init})
thread.setDaemon(True)
thread.start()
thread.join()
def init_connections(self, no_init=False):
'''
Sets up the initial Kazoo Client and watches
'''
success = False
self.set_valid(False)
if not no_init:
if self.zoo_client:
self.zoo_client.remove_listener(self.state_listener)
self.old_data = ''
self.old_pointed = ''
while not success:
try:
if self.zoo_client is None:
self.zoo_client = KazooClient(hosts=self.hosts)
self.zoo_client.start()
else:
# self.zoo_client.stop()
self.zoo_client._connection.connection_stopped.set()
self.zoo_client.close()
self.zoo_client = KazooClient(hosts=self.hosts)
self.zoo_client.start()
except Exception as e:
log.error("ZKWatcher Exception: " + e.message)
sleep(1)
continue
self.setup()
success = self.update_file(self.my_file)
sleep(5)
else:
self.setup()
self.update_file(self.my_file)
def setup(self):
'''
Ensures the path to the watched file exists and we have a state
listener
'''
self.zoo_client.add_listener(self.state_listener)
if self.ensure:
self.zoo_client.ensure_path(self.my_file)
def state_listener(self, state):
'''
Restarts the session if we get anything besides CONNECTED
'''
if state == KazooState.SUSPENDED:
self.set_valid(False)
self.call_error(self.BAD_CONNECTION)
elif state == KazooState.LOST and not self.do_not_restart:
self.threaded_start()
elif state == KazooState.CONNECTED:
# This is going to throw a SUSPENDED kazoo error
# which will cause the sessions to be wiped and re established.
# Used b/c of massive connection pool issues
self.zoo_client.stop()
def is_valid(self):
'''
@return: True if the currently watch file is valid
'''
return self.valid_file
def ping(self):
'''
Simple command to test if the zookeeper session is able to connect
at this very moment
'''
try:
# dummy ping to ensure we are still connected
self.zoo_client.server_version()
return True
except KazooException:
return False
def close(self, kill_restart=True):
'''
Use when you would like to close everything down
@param kill_restart= Prevent kazoo restarting from occurring
'''
self.do_not_restart = kill_restart
self.zoo_client.stop()
self.zoo_client.close()
def get_file_contents(self, pointer=False):
'''
Gets any file contents you care about. Defaults to the main file
@param pointer: The the contents of the file pointer, not the pointed
at file
@return: A string of the contents
'''
if self.pointer:
if pointer:
return self.old_pointed
else:
return self.old_data
else:
return self.old_data
def watch_file(self, event):
'''
Fired when changes made to the file
'''
if not self.update_file(self.my_file):
self.threaded_start()
def update_file(self, path):
'''
Updates the file watcher and calls the appropriate method for results
@return: False if we need to keep trying the connection
'''
try:
# grab the file
result, stat = self.zoo_client.get(path, watch=self.watch_file)
except ZookeeperError:
self.set_valid(False)
self.call_error(self.INVALID_GET)
return False
if self.pointer:
if result is not None and len(result) > 0:
self.pointed_at_expired = False
# file is a pointer, go update and watch other file
self.point_path = result
if self.compare_pointer(result):
self.update_pointed()
else:
self.pointed_at_expired = True
self.old_pointed = ''
self.old_data = ''
self.set_valid(False)
self.call_error(self.INVALID_PATH)
else:
# file is not a pointer, return contents
if self.compare_data(result):
self.call_config(result)
self.set_valid(True)
return True
def watch_pointed(self, event):
'''
Fired when changes made to pointed file
'''
self.update_pointed()
def update_pointed(self):
'''
Grabs the latest file contents based on the pointer uri
'''
# only grab file if our pointer is still good (not None)
if not self.pointed_at_expired:
try:
conf_string, stat2 = self.zoo_client.get(
self.point_path, watch=self.watch_pointed)
except ZookeeperError:
self.old_data = ''
self.set_valid(False)
self.pointed_at_expired = True
self.call_error(self.INVALID_PATH)
return
if self.compare_data(conf_string):
self.call_config(conf_string)
self.set_valid(True)
def set_valid(self, boolean):
'''
Sets the state and calls the change if needed
@param bool: The state (true or false)
'''
old_state = self.is_valid()
self.valid_file = boolean
if old_state != self.valid_file:
self.call_valid(self.valid_file)
def call_valid(self, state):
'''
Calls the valid change function passed in
@param valid_state: The new config
'''
if self.valid_handler is not None:
self.valid_handler(self.is_valid())
def call_config(self, new_config):
'''
Calls the config function passed in
@param new_config: The new config
'''
if self.config_handler is not None:
self.config_handler(new_config)
def call_error(self, message):
'''
Calls the error function passed in
@param message: The message to throw
'''
if self.error_handler is not None:
self.error_handler(message)
def compare_data(self, data):
'''
Compares the string data
@return: True if the data is different
'''
if self.old_data != data:
self.old_data = data
return True
return False
def compare_pointer(self, data):
'''
Compares the string data
@return: True if the data is different
'''
if self.old_pointed != data:
self.old_pointed = data
return True
return False
#!/bin/env python
# -*- coding: UTF-8 -*-
from kazoo.client import KazooClient
from kazoo.exceptions import *
import traceback
zk = KazooClient(hosts='127.0.0.1:2181')
zk.start()
# children = zk.get_children('/')
print "zk version:" + (".".join(str(x) for x in zk.server_version()))
print "client id :" + str(zk.client_id[0])
servicePath = "/{root}/{service}/provider".format(root="zkpyro", service="serviceName01")
nodeId = zk.client_id[0]
nodePath = "{servicePath}/{node}".format(servicePath=servicePath, node=nodeId)
print "servicePath:" + servicePath
try:
zk.create(nodePath, ephemeral=True, makepath=True)
zk.set(nodePath, "pyro.url")
print "Znode value:" + zk.get(nodePath)[0]
except NodeExistsError:
traceback.print_stack()
zk.stop()
class ZookeeperServiceRegistry(BaseServiceRegistry):
def __init__(self, hosts=DEFAULT_HOSTS, chroot=DEFAULT_CHROOT):
super(ZookeeperServiceRegistry, self).__init__()
self.chroot = chroot
self.client = KazooClient(
hosts=hosts,
handler=SequentialGeventHandler(),
)
self.client.add_listener(self.on_kazoo_state_change)
self.start_count = 0
@classmethod
def from_config(cls, config, **kwargs):
return cls(
hosts=config.get('hosts', DEFAULT_HOSTS),
chroot=config.get('chroot', DEFAULT_CHROOT),
**kwargs
)
def on_start(self, timeout=10):
self.start_count += 1
if self.start_count > 1:
return
started = self.client.start_async()
started.wait(timeout=timeout)
if not self.client.connected:
raise RuntimeError('could not connect to zookeeper')
logger.debug('connected to zookeeper (version=%s)', '.'.join(map(str, self.client.server_version())))
def on_stop(self):
self.start_count -= 1
if self.start_count != 0:
return
self.client.stop()
def on_kazoo_state_change(self, state):
logger.info('kazoo connection state changed to %s', state)
def on_service_type_watch(self, service, event):
try:
if event.type == EventType.CHILD:
# FIXME: figure out proper retry strategy
self.client.retry(self.lookup, service.container, service)
except Exception:
logger.exception('error in service type watcher')
def on_service_watch(self, service, event):
try:
prefix, service_type, identity = event.path.rsplit('/', 2)
if event.type == EventType.DELETED:
service.remove(identity)
except Exception:
logger.exception('error in service watcher')
def _get_service_znode(self, service, service_type, identity):
path = self._get_zk_path(service_type, identity)
result = self.client.get_async(
path, watch=functools.partial(self.on_service_watch, service))
value, znode = result.get()
items = six.iteritems(json.loads(value.decode('utf-8')))
return {str(k): str(v) for k, v in items}
def discover(self, container):
result = self.client.get_children_async(
path='%s/services' % self.chroot,
)
return list(result.get())
def lookup(self, container, service, watch=True, timeout=1):
def child_watch(event):
print(event)
service_type = service.service_type
result = self.client.get_children_async(
path='%s/services/%s' % (self.chroot, service_type),
watch=functools.partial(self.on_service_type_watch, service),
)
try:
names = result.get(timeout=timeout)
except NoNodeError:
raise LookupFailure(None, "failed to resolve %s" % service.service_type)
logger.info("lookup %s %r", service_type, names)
identities = set(service.identities())
for name in names:
kwargs = self._get_service_znode(service, service_type, name)
identity = kwargs.pop('identity')
service.update(identity, **kwargs)
try:
identities.remove(identity)
except KeyError:
pass
for identity in identities:
service.remove(identity)
return service
def _get_zk_path(self, service_type, identity):
return '%s/services/%s/%s' % (self.chroot, service_type, identity)
def register(self, container, service_type, timeout=1):
path = self._get_zk_path(service_type, container.identity)
value = json.dumps({
'endpoint': container.endpoint,
'identity': container.identity,
'log_endpoint': container.log_endpoint,
})
result = self.client.create_async(
path,
value.encode('utf-8'),
ephemeral=True, makepath=True)
# FIXME: result.set_exception(RegistrationFailure())
result.get(timeout=timeout)
def unregister(self, container, service_type, timeout=1):
path = self._get_zk_path(service_type, container.identity)
result = self.client.delete_async(path)
result.set_exception(RegistrationFailure())
result.get(timeout=timeout)
def watch(zookeepers, node, leader=False):
"""
Watch a particular zookeeper node for changes.
"""
zk_hosts = parse_zk_hosts(zookeepers, leader=leader)[0]
def my_listener(state):
if state == KazooState.LOST:
# Register somewhere that the session was lost
print(style_text('Connection Lost', ERROR_STYLE, pad=2))
elif state == KazooState.SUSPENDED:
# Handle being disconnected from Zookeeper
print(style_text('Connection Suspended', ERROR_STYLE, pad=2))
else:
# Handle being connected/reconnected to Zookeeper
# what are we supposed to do here?
print(style_text('Connected/Reconnected', INFO_STYLE, pad=2))
zk = KazooClient(hosts=zk_hosts, read_only=True)
try:
zk.start()
except KazooTimeoutError as e:
print('ZK Timeout host: [%s], %s' % (host, e))
zk_ver = '.'.join(map(str, zk.server_version()))
zk_host = zk.hosts[zk.last_zxid]
zk_host = ':'.join(map(str, zk_host))
zk.add_listener(my_listener)
# check if the node exists ...
if not zk.exists(node):
node_str = style_text(node, BLUE_STYLE, restore=ERROR_STYLE)
zk_str = style_text(zk_host, BLUE_STYLE, restore=ERROR_STYLE)
print('')
print(
style_text('No node [%s] on %s' % (node_str, zk_str),
ERROR_STYLE,
pad=2))
return
print(style_header('Watching [%s] on %s v%s' % (node, zk_host, zk_ver)))
# put a watch on my znode
children = zk.get_children(node)
# If there are children, watch them.
if children or node.endswith('/'):
@zk.ChildrenWatch(node)
def watch_children(children):
global WATCH_COUNTER
WATCH_COUNTER += 1
if WATCH_COUNTER <= 1:
child_watch_str = 'Child Nodes:'
else:
child_watch_str = 'Node Watch Event: '
children.sort()
print('')
print(style_text(child_watch_str, TITLE_STYLE))
for ch in children:
print(style_text(ch, INFO_STYLE, lpad=2))
print('')
else:
# otherwise watch the node itself.
@zk.DataWatch(node)
def watch_data(data, stat, event):
global WATCH_COUNTER
WATCH_COUNTER += 1
data = data.decode('utf-8')
if WATCH_COUNTER <= 1:
data_watch_str = 'Content: (%s)'
else:
data_watch_str = 'Data Watch Event: (v%s)'
print('')
print(style_text(data_watch_str % stat.version, TITLE_STYLE))
print(style_multiline(data, INFO_STYLE, lpad=2))
print('')
CHAR_WIDTH = 60
counter = 0
while True:
# draw a .... animation while we wait, so the user knows its working.
counter += 1
if not counter % CHAR_WIDTH:
print('\r', ' ' * CHAR_WIDTH, '\r', end='')
print(style_text('.', INFO_STYLE), end='')
time.sleep(0.05)
zk.stop()
class USSMetadataManager(object):
"""Interfaces with the locking system to get, put, and delete USS metadata.
Metadata gets/stores/deletes the USS information for a partiular grid,
including current version number, a list of USSs with active operations,
and the endpoints to get that information. Locking is assured through a
snapshot token received when getting, and used when putting.
"""
def __init__(self, connectionstring=DEFAULT_CONNECTION, testgroupid=None):
"""Initializes the class.
Args:
connectionstring:
Zookeeper connection string - server:port,server:port,...
testgroupid:
ID to use if in test mode, none for normal mode
"""
if testgroupid:
self.set_testmode(testgroupid)
if not connectionstring:
connectionstring = DEFAULT_CONNECTION
log.debug(
'Creating metadata manager object and connecting to zookeeper...')
try:
if set(BAD_CHARACTER_CHECK) & set(connectionstring):
raise ValueError
self.zk = KazooClient(hosts=connectionstring,
timeout=CONNECTION_TIMEOUT)
self.zk.add_listener(self.zookeeper_connection_listener)
self.zk.start()
if testgroupid:
self.delete_testdata(testgroupid)
except KazooTimeoutError:
log.error(
'Unable to connect to zookeeper using %s connection string...',
connectionstring)
raise
except ValueError:
log.error('Connection string %s seems invalid...',
connectionstring)
raise
def __del__(self):
log.debug(
'Destroying metadata manager object and disconnecting from zk...')
self.zk.stop()
def get_state(self):
return self.zk.state
def get_version(self):
try:
return True, self.zk.server_version()
except KazooException as e:
msg = str(e)
return False, type(e).__name__ + (' ' + msg if msg else '')
def set_verbose(self):
log.setLevel(logging.DEBUG)
def set_testmode(self, testgroupid='UNDEFINED_TESTER'):
"""Sets the mode to testing with the specific test ID, cannot be undone.
Args:
testgroupid: ID to use if in test mode, none for normal mode
"""
global GRID_PATH
global CONNECTION_TIMEOUT
# Adjust parameters specifically for the test
GRID_PATH = TEST_BASE_PREFIX + testgroupid + USS_BASE_PREFIX
log.debug('Setting test path to %s...', GRID_PATH)
CONNECTION_TIMEOUT = 1.0
def zookeeper_connection_listener(self, state):
if state == KazooState.LOST:
# Register somewhere that the session was lost
log.error('Lost connection with the zookeeper servers...')
elif state == KazooState.SUSPENDED:
# Handle being disconnected from Zookeeper
log.error('Suspended connection with the zookeeper servers...')
elif state == KazooState.CONNECTED:
# Handle being connected/reconnected to Zookeeper
log.info('Connection restored with the zookeeper servers...')
def delete_testdata(self, testgroupid=None):
"""Removes the test data from the servers.
Be careful when using this in parallel as it removes everything under
the testgroupid, or everything if no tetgroupid is provided.
Args:
testgroupid: ID to use if in test mode, none will remove all test data
"""
if testgroupid:
path = TEST_BASE_PREFIX + testgroupid
else:
path = TEST_BASE_PREFIX
self.zk.delete(path, recursive=True)
def get(self, z, x, y):
"""Gets the metadata and snapshot token for a GridCell.
Reads data from zookeeper, including a snapshot token. The
snapshot token is used as a reference when writing to ensure
the data has not been updated between read and write.
Args:
z: zoom level in slippy tile format
x: x tile number in slippy tile format
y: y tile number in slippy tile format
Returns:
JSend formatted response (https://labs.omniti.com/labs/jsend)
"""
# TODO(hikevin): Change to use our own error codes and let the server
# convert them to http error codes. For now, this is
# at least in a standard JSend format.
status = 500
if slippy_util.validate_slippy(z, x, y):
(content, metadata) = self._get_raw(z, x, y)
if metadata:
try:
m = uss_metadata.USSMetadata(content)
status = 200
result = {
'status': 'success',
'sync_token': metadata.last_modified_transaction_id,
'data': m.to_json()
}
except ValueError:
status = 424
else:
status = 404
else:
status = 400
if status != 200:
result = self._format_status_code_to_jsend(status)
return result
def set(self, z, x, y, sync_token, uss_id, ws_scope, operation_format,
operation_ws, earliest_operation, latest_operation):
"""Sets the metadata for a GridCell.
Writes data, using the snapshot token for confirming data
has not been updated since it was last read.
Args:
z: zoom level in slippy tile format
x: x tile number in slippy tile format
y: y tile number in slippy tile format
sync_token: token retrieved in the original GET GridCellMetadata,
uss_id: plain text identifier for the USS,
ws_scope: scope to use to obtain OAuth token,
operation_format: output format for operation ws (i.e. NASA, GUTMA),
operation_ws: submitting USS endpoint where all flights in
this cell can be retrieved from,
earliest_operation: lower bound of active or planned flight timestamp,
used for quick filtering conflicts.
latest_operation: upper bound of active or planned flight timestamp,
used for quick filtering conflicts.
Returns:
JSend formatted response (https://labs.omniti.com/labs/jsend)
"""
if slippy_util.validate_slippy(z, x, y):
# first we have to get the cell
(content, metadata) = self._get_raw(z, x, y)
if metadata:
# Quick check of the token, another is done on the actual set to be sure
# but this check fails early and fast
if str(metadata.last_modified_transaction_id) == str(
sync_token):
try:
m = uss_metadata.USSMetadata(content)
log.debug('Setting metadata for %s...', uss_id)
if not m.upsert_operator(
uss_id, ws_scope, operation_format,
operation_ws, earliest_operation,
latest_operation, z, x, y):
log.error(
'Failed setting operator for %s with token %s...',
uss_id, str(sync_token))
raise ValueError
status = self._set_raw(z, x, y, m, metadata.version)
except ValueError:
status = 424
else:
status = 409
else:
status = 404
else:
status = 400
if status == 200:
# Success, now get the metadata back to send back
result = self.get(z, x, y)
else:
result = self._format_status_code_to_jsend(status)
return result
def delete(self, z, x, y, uss_id):
"""Sets the metadata for a GridCell by removing the entry for the USS.
Args:
z: zoom level in slippy tile format
x: x tile number in slippy tile format
y: y tile number in slippy tile format
uss_id: is the plain text identifier for the USS
Returns:
JSend formatted response (https://labs.omniti.com/labs/jsend)
"""
status = 500
if slippy_util.validate_slippy(z, x, y):
# first we have to get the cell
(content, metadata) = self._get_raw(z, x, y)
if metadata:
try:
m = uss_metadata.USSMetadata(content)
m.remove_operator(uss_id)
# TODO(pelletierb): Automatically retry on delete
status = self._set_raw(z, x, y, m, metadata.version)
except ValueError:
status = 424
else:
status = 404
else:
status = 400
if status == 200:
# Success, now get the metadata back to send back
(content, metadata) = self._get_raw(z, x, y)
result = {
'status': 'success',
'sync_token': metadata.last_modified_transaction_id,
'data': m.to_json()
}
else:
result = self._format_status_code_to_jsend(status)
return result
def get_multi(self, z, grids):
"""Gets the metadata and snapshot token for multiple GridCells.
Reads data from zookeeper, including a composite snapshot token. The
snapshot token is used as a reference when writing to ensure
the data has not been updated between read and write.
Args:
z: zoom level in slippy tile format
grids: list of (x,y) tiles to retrieve
Returns:
JSend formatted response (https://labs.omniti.com/labs/jsend)
"""
try:
combined_meta, syncs = self._get_multi_raw(z, grids)
log.debug('Found sync token %s for %d grids...',
self._hash_sync_tokens(syncs), len(syncs))
result = {
'status': 'success',
'sync_token': self._hash_sync_tokens(syncs),
'data': combined_meta.to_json()
}
except ValueError as e:
result = self._format_status_code_to_jsend(400, e.message)
except IndexError as e:
result = self._format_status_code_to_jsend(404, e.message)
return result
def set_multi(self, z, grids, sync_token, uss_id, ws_scope,
operation_format, operation_ws, earliest_operation,
latest_operation):
"""Sets multiple GridCells metadata at once.
Writes data, using the hashed snapshot token for confirming data
has not been updated since it was last read.
Args:
z: zoom level in slippy tile format
grids: list of (x,y) tiles to update
sync_token: token retrieved in the original get_multi,
uss_id: plain text identifier for the USS,
ws_scope: scope to use to obtain OAuth token,
operation_format: output format for operation ws (i.e. NASA, GUTMA),
operation_ws: submitting USS endpoint where all flights in
this cell can be retrieved from,
earliest_operation: lower bound of active or planned flight timestamp,
used for quick filtering conflicts.
latest_operation: upper bound of active or planned flight timestamp,
used for quick filtering conflicts.
Returns:
JSend formatted response (https://labs.omniti.com/labs/jsend)
"""
log.debug('Setting multiple grid metadata for %s...', uss_id)
try:
# first, get the affected grid's sync tokens
m, syncs = self._get_multi_raw(z, grids)
del m
# Quick check of the token, another is done on the actual set to be sure
# but this check fails early and fast
log.debug('Found sync token %d for %d grids...',
self._hash_sync_tokens(syncs), len(syncs))
if str(self._hash_sync_tokens(syncs)) == str(sync_token):
log.debug('Composite sync_token matches, continuing...')
self._set_multi_raw(z, grids, syncs, uss_id, ws_scope,
operation_format, operation_ws,
earliest_operation, latest_operation)
log.debug('Completed updating multiple grids...')
else:
raise KeyError('Composite sync_token has changed')
combined_meta, new_syncs = self._get_multi_raw(z, grids)
result = {
'status': 'success',
'sync_token': self._hash_sync_tokens(new_syncs),
'data': combined_meta.to_json()
}
except (KeyError, RolledBackError) as e:
result = self._format_status_code_to_jsend(409, e.message)
except ValueError as e:
result = self._format_status_code_to_jsend(400, e.message)
except IndexError as e:
result = self._format_status_code_to_jsend(404, e.message)
return result
def delete_multi(self, z, grids, uss_id):
"""Sets multiple GridCells metadata by removing the entry for the USS.
Removes the operator from multiple cells. Does not return 404 on
not finding the USS in a cell, since this should be a remove all
type function, as some cells might have the ussid and some might not.
Args:
z: zoom level in slippy tile format
grids: list of (x,y) tiles to delete
uss_id: is the plain text identifier for the USS
Returns:
JSend formatted response (https://labs.omniti.com/labs/jsend)
"""
log.debug('Deleting multiple grid metadata for %s...', uss_id)
try:
if not uss_id:
raise ValueError('Invalid uss_id for deleting multi')
for x, y in grids:
if slippy_util.validate_slippy(z, x, y):
(content, metadata) = self._get_raw(z, x, y)
if metadata:
m = uss_metadata.USSMetadata(content)
m.remove_operator(uss_id)
# TODO(pelletierb): Automatically retry on delete
status = self._set_raw(z, x, y, m, metadata.version)
else:
raise ValueError('Invalid slippy grids for lookup')
result = self.get_multi(z, grids)
except ValueError as e:
result = self._format_status_code_to_jsend(400, e.message)
return result
######################################################################
################ INTERNAL FUNCTIONS #########################
######################################################################
def _get_raw(self, z, x, y):
"""Gets the raw content and metadata for a GridCell from zookeeper.
Args:
z: zoom level in slippy tile format
x: x tile number in slippy tile format
y: y tile number in slippy tile format
Returns:
content: USS metadata
metadata: straight from zookeeper
"""
path = '%s/%s/%s/%s/%s' % (GRID_PATH, str(z), str(x), str(y),
USS_METADATA_FILE)
log.debug('Getting metadata from zookeeper@%s...', path)
try:
c, m = self.zk.get(path)
except NoNodeError:
self.zk.ensure_path(path)
c, m = self.zk.get(path)
if c:
log.debug('Received raw content and metadata from zookeeper: %s',
c)
if m:
log.debug('Received raw metadata from zookeeper: %s', m)
return c, m
def _set_raw(self, z, x, y, m, version):
"""Grabs the lock and updates the raw content for a GridCell in zookeeper.
Args:
z: zoom level in slippy tile format
x: x tile number in slippy tile format
y: y tile number in slippy tile format
m: metadata object to write
version: the metadata version verified from the sync_token match
Returns:
200 for success, 409 for conflict, 408 for unable to get the lock
"""
path = '%s/%s/%s/%s/%s' % (GRID_PATH, str(z), str(x), str(y),
USS_METADATA_FILE)
try:
log.debug('Setting metadata to %s...', str(m))
self.zk.set(path, json.dumps(m.to_json()), version)
status = 200
except BadVersionError:
log.error('Sync token updated before write for %s...', path)
status = 409
return status
def _get_multi_raw(self, z, grids):
"""Gets the raw content and metadata for multiple GridCells from zookeeper.
Args:
z: zoom level in slippy tile format
grids: list of (x,y) tiles to retrieve
Returns:
content: Combined USS metadata
syncs: list of sync tokens in the same order as the grids
Raises:
IndexError: if it cannot find anything in zookeeper
ValueError: if the grid data is not in the right format
"""
log.debug('Getting multiple grid metadata for %s...', str(grids))
combined_meta = None
syncs = []
for x, y in grids:
if slippy_util.validate_slippy(z, x, y):
(content, metadata) = self._get_raw(z, x, y)
if metadata:
combined_meta += uss_metadata.USSMetadata(content)
syncs.append(metadata.last_modified_transaction_id)
else:
raise IndexError('Unable to find metadata in platform')
else:
raise ValueError('Invalid slippy grids for lookup')
if len(syncs) == 0:
raise IndexError('Unable to find metadata in platform')
return combined_meta, syncs
def _set_multi_raw(self, z, grids, sync_tokens, uss_id, ws_scope,
operation_format, operation_ws, earliest_operation,
latest_operation):
"""Grabs the lock and updates the raw content for multiple GridCells
Args:
z: zoom level in slippy tile format
grids: list of (x,y) tiles to retrieve
sync_tokens: list of the sync tokens received during get operation
uss_id: plain text identifier for the USS,
ws_scope: scope to use to obtain OAuth token,
operation_format: output format for operation ws (i.e. NASA, GUTMA),
operation_ws: submitting USS endpoint where all flights in
this cell can be retrieved from,
earliest_operation: lower bound of active or planned flight timestamp,
used for quick filtering conflicts.
latest_operation: upper bound of active or planned flight timestamp,
used for quick filtering conflicts.
Raises:
IndexError: if it cannot find anything in zookeeper
ValueError: if the grid data is not in the right format
"""
log.debug('Setting multiple grid metadata for %s...', str(grids))
try:
contents = []
for i in range(len(grids)):
# First, get and update them all in memory, validate the sync_token
x = grids[i][0]
y = grids[i][1]
sync_token = sync_tokens[i]
path = '%s/%s/%s/%s/%s' % (GRID_PATH, str(z), str(x), str(y),
USS_METADATA_FILE)
(content, metadata) = self._get_raw(z, x, y)
if str(metadata.last_modified_transaction_id) == str(
sync_token):
log.debug('Sync_token matches for %d, %d...', x, y)
m = uss_metadata.USSMetadata(content)
if not m.upsert_operator(
uss_id, ws_scope, operation_format, operation_ws,
earliest_operation, latest_operation, z, x, y):
raise ValueError('Failed to set operator content')
contents.append((path, m, metadata.version))
else:
log.error(
'Sync token from USS (%s) does not match token from zk (%s)...',
str(sync_token),
str(metadata.last_modified_transaction_id))
raise KeyError('Composite sync_token has changed')
# Now, start a transaction to update them all
# the version will catch any changes and roll back any attempted
# updates to the grids
log.debug('Starting transaction to write all grids at once...')
t = self.zk.transaction()
for path, m, version in contents:
t.set_data(path, json.dumps(m.to_json()), version)
log.debug('Committing transaction...')
results = t.commit()
if isinstance(results[0], RolledBackError):
raise KeyError(
'Rolled back multi-grid transaction due to grid change')
log.debug('Committed transaction successfully.')
except (KeyError, ValueError, IndexError) as e:
log.error('Error caught in set_multi_raw %s.', e.message)
raise e
def _format_status_code_to_jsend(self, status, message=None):
"""Formats a response based on HTTP status code.
Args:
status: HTTP status code
message: optional message to override preset message for codes
Returns:
JSend formatted response (https://labs.omniti.com/labs/jsend)
"""
if status == 200 or status == 204:
result = {
'status': 'success',
'code': 204,
'message': 'Empty data set.'
}
elif status == 400:
result = {
'status': 'fail',
'code': status,
'message': 'Parameters are not following the correct format.'
}
elif status == 404:
result = {
'status': 'fail',
'code': status,
'message': 'Unable to pull metadata from lock system.'
}
elif status == 408:
result = {
'status': 'fail',
'code': status,
'message': 'Timeout trying to get lock.'
}
elif status == 409:
result = {
'status':
'fail',
'code':
status,
'message':
'Content in metadata has been updated since provided sync token.'
}
elif status == 424:
result = {
'status':
'fail',
'code':
status,
'message':
'Content in metadata is not following JSON format guidelines.'
}
else:
result = {
'status': 'fail',
'code': status,
'message': 'Unknown error code occurred.'
}
if message:
result['message'] = message
return result
@staticmethod
def _hash_sync_tokens(syncs):
"""Hashes a list of sync tokens into a single, positive 64-bit int.
For various languages, the limit to integers may be different, therefore
we truncate to ensure the hash is the same on all implementations.
"""
return abs(hash(tuple(sorted(syncs)))) % MAX_SAFE_INTEGER
打印zookeeper树
'''
from kazoo.client import KazooClient
from kazoo.client import KazooState
import datetime
import time
hosts = '10.48.57.42:8581,10.48.57.42:8582,10.48.57.42:8583'
zk = KazooClient(hosts=hosts)
zk.start()
print "hosts", hosts
print "version", zk.server_version()
#
#
#
def printTreeNode(basepath, node, i):
if isinstance(node, list):
for item in node:
# current
current_base_path = basepath + "/" + item
data, stat = zk.get(current_base_path)
ahead = ""
@author: liaoqiqi
打印zookeeper树
"""
from kazoo.client import KazooClient
import time
hosts = '127.0.0.1:3307'
zk = KazooClient(hosts=hosts)
zk.start()
print "hosts", hosts
print "version", zk.server_version()
#
#
#
def printTreeNode(basepath, node, i):
if isinstance(node, list):
for item in node:
# current
current_base_path = basepath + "/" + item
data, stat = zk.get(current_base_path)
ahead = ""
j = 1
while j < i: