zuul/nodepool
Code Issues Proposed changes

Have buildZooKeeperHosts accept a config object

Browse Source 
Add a new ZooKeeperServerConnection class which represents the
information needed to connect to a server, and then have the
config parser create that object instead of its own internal
representation of the connection.  Modify the ZooKeeper class
to accept this new object to specify what connection(s) it
should use.

The new class implements the equality operator so that it may
still be used in the same way as other ConfigValue objects (that
is, checking to see if the configuration has been updated).

Change-Id: I4cfa3866e3b0ae2a730c1e624570cd7025901808
This commit is contained in:
James E. Blair 2016-08-18 09:48:18 -07:00
parent 76a691e5f4
commit 49da9c0c92
3 changed files with 56 additions and 36 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
nodepool/config.py
View File

@ -21,6 +21,7 @@ from six.moves import configparser as ConfigParser
import yaml
import fakeprovider
import zk
class ConfigValue(object):
@ -102,10 +103,6 @@ class GearmanServer(ConfigValue):
pass
class ZooKeeperServer(ConfigValue):
pass
class DiskImage(ConfigValue):
pass
@ -161,12 +158,11 @@ def loadConfig(config_path):
newconfig.gearman_servers[g.name] = g
for server in config.get('zookeeper-servers', []):
z = ZooKeeperServer()
z.host = server['host']
z.port = server.get('port', 2181)
z.chroot = server.get('chroot', '')
z.name = z.host + '_' + str(z.port)
newconfig.zookeeper_servers[z.name] = z
z = zk.ZooKeeperConnectionConfig(server['host'],
server.get('port', 2181),
server.get('chroot', None))
name = z.host + '_' + str(z.port)
newconfig.zookeeper_servers[name] = z
for provider in config.get('providers', []):
p = Provider()

21
nodepool/tests/test_zk.py
View File

@ -26,15 +26,18 @@ class TestZooKeeper(tests.ZKTestCase):
def test_buildZooKeeperHosts_single(self):
hosts = [
dict(host='127.0.0.1', port=2181, chroot='/test1')
zk.ZooKeeperConnectionConfig('127.0.0.1', port=2181,
chroot='/test1')
]
self.assertEqual('127.0.0.1:2181/test1',
zk.buildZooKeeperHosts(hosts))
def test_buildZooKeeperHosts_multiple(self):
hosts = [
dict(host='127.0.0.1', port=2181, chroot='/test1'),
dict(host='127.0.0.2', port=2182, chroot='/test2')
zk.ZooKeeperConnectionConfig('127.0.0.1', port=2181,
chroot='/test1'),
zk.ZooKeeperConnectionConfig('127.0.0.2', port=2182,
chroot='/test2')
]
self.assertEqual('127.0.0.1:2181/test1,127.0.0.2:2182/test2',
zk.buildZooKeeperHosts(hosts))
@ -89,9 +92,9 @@ class TestZooKeeper(tests.ZKTestCase):
def test_imageBuildLock_exception_nonblocking(self):
zk2 = zk.ZooKeeper()
zk2.connect([{'host': self.zookeeper_host,
'port': self.zookeeper_port,
'chroot': self.chroot_path}])
zk2.connect([zk.ZooKeeperConnectionConfig(self.zookeeper_host,
port=self.zookeeper_port,
chroot=self.chroot_path)])
with zk2.imageBuildLock("ubuntu-trusty", blocking=False):
with testtools.ExpectedException(npe.ZKLockException):
with self.zk.imageBuildLock("ubuntu-trusty", blocking=False):
@ -100,9 +103,9 @@ class TestZooKeeper(tests.ZKTestCase):
def test_imageBuildLock_exception_blocking(self):
zk2 = zk.ZooKeeper()
zk2.connect([{'host': self.zookeeper_host,
'port': self.zookeeper_port,
'chroot': self.chroot_path}])
zk2.connect([zk.ZooKeeperConnectionConfig(self.zookeeper_host,
port=self.zookeeper_port,
chroot=self.chroot_path)])
with zk2.imageBuildLock("ubuntu-trusty", blocking=False):
with testtools.ExpectedException(npe.TimeoutException):
with self.zk.imageBuildLock("ubuntu-trusty",

55
nodepool/zk.py
View File

@ -22,30 +22,49 @@ from kazoo.recipe.lock import Lock
from nodepool import exceptions as npe
class ZooKeeperConnectionConfig(object):
'''
Represents the connection parameters for a ZooKeeper server.
'''
def __eq__(self, other):
if isinstance(other, ZooKeeperConnectionConfig):
if other.__dict__ == self.__dict__:
return True
return False
def __init__(self, host, port=2181, chroot=None):
'''Initialize the ZooKeeperConnectionConfig object.
:param str host: The hostname of the ZooKeeper server.
:param int port: The port on which ZooKeeper is listening.
Optional, default: 2181.
:param str chroot: A chroot for this connection. All
ZooKeeper nodes will be underneath this root path.
Optional, default: None.
(one per server) defining the ZooKeeper cluster servers. Only
the 'host' attribute is required.'.
'''
self.host = host
self.port = port
self.chroot = chroot or ''
def buildZooKeeperHosts(host_list):
'''
Build the ZK cluster host list for client connections.
:param list host_list: A list of dicts (one per server) defining
the ZooKeeper cluster servers. Keys for 'host', 'port', and
'chroot' are expected. Only 'host' is required.'. E.g.::
[
dict(host='192.168.0.2'),
dict(host='192.168.0.3', port=2181, chroot='/junk')
]
:param list host_list: A list of
:py:class:`~nodepool.zk.ZooKeeperConnectionConfig` objects (one
per server) defining the ZooKeeper cluster servers.
'''
if not isinstance(host_list, list):
raise Exception("'host_list' must be a list")
hosts = []
for host_def in host_list:
host = host_def['host']
if 'port' in host_def:
host = host + ":%s" % host_def['port']
else:
host = host + ":2181"
if 'chroot' in host_def:
host = host + host_def['chroot']
host = '%s:%s%s' % (host_def.host, host_def.port, host_def.chroot)
hosts.append(host)
return ",".join(hosts)
@ -162,10 +181,12 @@ class ZooKeeper(object):
Convenience method if a pre-existing ZooKeeper connection is not
supplied to the ZooKeeper object at instantiation time.
:param list host_list: A list of dicts (one per server) defining
the ZooKeeper cluster servers.
:param list host_list: A list of
:py:class:`~nodepool.zk.ZooKeeperConnectionConfig` objects
(one per server) defining the ZooKeeper cluster servers.
:param bool read_only: If True, establishes a read-only connection.
'''
if not self.client:
hosts = buildZooKeeperHosts(host_list)