Ema has submitted this change and it was merged. (
https://gerrit.wikimedia.org/r/404713 )
Change subject: Separate out coordinator.Server into its own module
......................................................................
Separate out coordinator.Server into its own module
Change-Id: I925f0abe553cd82603014cd8a0760be8bc8ad880
---
M pybal/coordinator.py
A pybal/server.py
M pybal/test/test_coordinator.py
M pybal/test/test_server.py
4 files changed, 277 insertions(+), 264 deletions(-)
Approvals:
Ema: Looks good to me, approved
jenkins-bot: Verified
diff --git a/pybal/coordinator.py b/pybal/coordinator.py
index a4b4e16..b7b3591 100755
--- a/pybal/coordinator.py
+++ b/pybal/coordinator.py
@@ -6,270 +6,14 @@
LVS Squid balancer/monitor for managing the Wikimedia Squid servers using LVS
"""
-import importlib
-import random
-import socket
-from twisted.internet import defer, reactor
-from twisted.names import client, dns
-from twisted.python import failure
+from twisted.internet import defer
from pybal import config, util
from pybal.metrics import Counter, Gauge
+import pybal.server
log = util.log
-
-
-class Server:
- """
- Class that maintains configuration and state of a single (real)server
- """
-
- # Defaults
- DEF_STATE = True
- DEF_WEIGHT = 10
-
- # Set of attributes allowed to be overridden in a server list
- allowedConfigKeys = [ ('host', str), ('weight', int), ('enabled', bool) ]
-
- def __init__(self, host, lvsservice, addressFamily=None):
- """Constructor"""
-
- self.host = host
- self.lvsservice = lvsservice
- if addressFamily:
- self.addressFamily = addressFamily
- else:
- self.addressFamily = (':' in self.lvsservice.ip) and
socket.AF_INET6 or socket.AF_INET
- self.ip = None
- self.port = 80
- self.ip4_addresses = set()
- self.ip6_addresses = set()
- self.monitors = set()
-
- # A few invariants that SHOULD be maintained (but currently may not
be):
- # P0: pooled => enabled /\ ready
- # P1: up => pooled \/ !enabled \/ !ready
- # P2: pooled => up \/ !canDepool
-
- self.weight = self.DEF_WEIGHT
- self.up = False
- self.pooled = False
- self.enabled = True
- self.ready = False
- self.modified = None
-
- def __eq__(self, other):
- return isinstance(other, Server) and self.host == other.host and
self.lvsservice == other.lvsservice
-
- def __hash__(self):
- return hash(self.host)
-
- def addMonitor(self, monitor):
- """Adds a monitor instance to the set"""
-
- self.monitors.add(monitor)
-
- def removeMonitors(self):
- """Removes all monitors"""
-
- for monitor in self.monitors:
- monitor.stop()
-
- self.monitors.clear()
-
- def resolveHostname(self):
- """Attempts to resolve the server's hostname to an IP address for
better reliability."""
-
- timeout = [1, 2, 5]
- lookups = []
-
- query = dns.Query(self.host, dns.A)
- lookups.append(client.lookupAddress(self.host, timeout
- ).addCallback(self._lookupFinished, socket.AF_INET, query))
-
- query = dns.Query(self.host, dns.AAAA)
- lookups.append(client.lookupIPV6Address(self.host, timeout
- ).addCallback(self._lookupFinished, socket.AF_INET6, query))
-
- return defer.DeferredList(lookups).addBoth(self._hostnameResolved)
-
- def _lookupFinished(self, (answers, authority, additional), addressFamily,
query):
- ips = set([socket.inet_ntop(addressFamily, r.payload.address)
- for r in answers
- if r.name == query.name and r.type == query.type])
-
- if query.type == dns.A:
- self.ip4_addresses = ips
- elif query.type == dns.AAAA:
- self.ip6_addresses = ips
-
- # TODO: expire TTL
- #if self.ip:
- # minTTL = min([r.ttl for r in answers
- # if r.name == query.name and r.type == query.type])
-
- return ips
-
- def _hostnameResolved(self, result):
- # Pick *1* main ip address to use. Prefer any existing one
- # if still available.
-
- addr = " ".join(
- list(self.ip4_addresses) + list(self.ip6_addresses))
- msg = "Resolved {} to addresses {}".format(self.host, addr)
- log.debug(msg)
-
- ip_addresses = {
- socket.AF_INET:
- self.ip4_addresses,
- socket.AF_INET6:
- self.ip6_addresses
- }[self.addressFamily]
-
- try:
- if not self.ip or self.ip not in ip_addresses:
- self.ip = random.choice(list(ip_addresses))
- # TODO: (re)pool
- except IndexError:
- return failure.Failure() # TODO: be more specific?
- else:
- return True
-
- def destroy(self):
- self.enabled = False
- self.removeMonitors()
-
- def initialize(self, coordinator):
- """
- Initializes this server instance and fires a Deferred
- when ready for use (self.ready == True)
- """
-
- d = self.resolveHostname()
-
- return d.addCallbacks(self._ready, self._initFailed,
callbackArgs=[coordinator])
-
- def _ready(self, result, coordinator):
- """
- Called when initialization has finished.
- """
-
- self.ready = True
- self.up = self.DEF_STATE
- self.pooled = self.DEF_STATE
- self.maintainState()
-
- self.createMonitoringInstances(coordinator)
-
- return True
-
- def _initFailed(self, fail):
- """
- Called when initialization failed
- """
- log.error("Initialization failed for server {}".format(self.host))
-
- assert self.ready == False
- self.maintainState()
-
- return False # Continue on success callback chain
-
- def createMonitoringInstances(self, coordinator):
- """Creates and runs monitoring instances for this Server"""
-
- lvsservice = self.lvsservice
-
- try:
- monitorlist = eval(lvsservice.configuration['monitors'])
- except KeyError:
- log.critical(
- "LVS service {} does not have a 'monitors' configuration
option set.".format(
- lvsservice.name)
- )
- raise
-
- if type(monitorlist) != list:
- msg = "option 'monitors' in LVS service section {} is not a python
list"
- log.err(msg.format(lvsservice.name))
- else:
- for monitorname in monitorlist:
- try:
- monitormodule = importlib.import_module(
- "pybal.monitors.{}".format(monitorname.lower()))
- except ImportError:
- log.err("Monitor {} does not exist".format(monitorname))
- except Exception:
- log.critical("Cannot import
pybal.monitors.{}".format(monitorname))
- # An exception was raised importing the given monitor
- # module. Instead of just logging the problem, stop PyBal
- # as the admin might think everything is fine and all
- # checks are green, while in fact no check is being
- # performed.
- reactor.stop()
- else:
- monitorclass = getattr(monitormodule, monitorname +
'MonitoringProtocol')
- monitor = monitorclass(coordinator, self,
lvsservice.configuration)
- self.addMonitor(monitor)
- monitor.run()
-
- def calcStatus(self):
- """AND quantification of monitor.up over all monitoring instances of a
single Server"""
-
- # Global status is up iff all monitors report up
- return reduce(lambda b,monitor: b and monitor.up, self.monitors,
len(self.monitors) != 0)
-
- def calcPartialStatus(self):
- """OR quantification of monitor.up over all monitoring instances of a
single Server"""
-
- # Partial status is up iff one of the monitors reports up
- return reduce(lambda b,monitor: b or monitor.up, self.monitors,
len(self.monitors) == 0)
-
- def textStatus(self):
- return "%s/%s/%s" % (self.enabled and "enabled" or "disabled",
- self.up and "up" or (self.calcPartialStatus() and
"partially up" or "down"),
- self.pooled and "pooled" or "not pooled")
-
- def maintainState(self):
- """Maintains a few invariants on configuration changes"""
-
- # P0
- if not self.enabled or not self.ready:
- self.pooled = False
- # P1
- if not self.pooled and self.enabled:
- self.up = False
-
- def merge(self, configuration):
- """Merges in configuration from a dictionary of (allowed) attributes"""
-
- for key, value in configuration.iteritems():
- if (key, type(value)) not in self.allowedConfigKeys:
- del configuration[key]
-
- # Overwrite configuration
- self.__dict__.update(configuration)
- self.maintainState()
- self.modified = True # Indicate that this instance previously
existed
-
- def dumpState(self):
- """Dump current state of the server"""
- return {'pooled': self.pooled, 'weight': self.weight,
- 'up': self.up, 'enabled': self.enabled}
-
- @classmethod
- def buildServer(cls, hostName, configuration, lvsservice):
- """
- Factory method which builds a Server instance from a
- dictionary of (allowed) configuration attributes
- """
-
- server = cls(hostName, lvsservice) # create a new instance...
- server.merge(configuration) # ...and override attributes
- server.modified = False
-
- return server
-
class Coordinator:
"""
@@ -478,7 +222,7 @@
)
else:
# New server
- server = Server.buildServer(hostName, hostConfig,
self.lvsservice)
+ server = pybal.server.Server.buildServer(hostName, hostConfig,
self.lvsservice)
data = {'status': (server.enabled and "enabled" or "disabled"),
'host': hostName, 'weight': server.weight}
# Initialize with LVS service specific configuration
diff --git a/pybal/server.py b/pybal/server.py
new file mode 100644
index 0000000..48b35fc
--- /dev/null
+++ b/pybal/server.py
@@ -0,0 +1,268 @@
+"""
+PyBal
+Copyright (C) 2006-2018 by Mark Bergsma <[email protected]>
+
+LVS balancer/monitor
+"""
+
+import importlib
+import random
+import socket
+
+from twisted.internet import defer, reactor
+from twisted.names import client, dns
+from twisted.python import failure
+
+from pybal import util
+
+log = util.log
+
+class Server:
+ """
+ Class that maintains configuration and state of a single (real)server
+ """
+
+ # Defaults
+ DEF_STATE = True
+ DEF_WEIGHT = 10
+
+ # Set of attributes allowed to be overridden in a server list
+ allowedConfigKeys = [ ('host', str), ('weight', int), ('enabled', bool) ]
+
+ def __init__(self, host, lvsservice, addressFamily=None):
+ """Constructor"""
+
+ self.host = host
+ self.lvsservice = lvsservice
+ if addressFamily:
+ self.addressFamily = addressFamily
+ else:
+ self.addressFamily = (':' in self.lvsservice.ip) and
socket.AF_INET6 or socket.AF_INET
+ self.ip = None
+ self.port = 80
+ self.ip4_addresses = set()
+ self.ip6_addresses = set()
+ self.monitors = set()
+
+ # A few invariants that SHOULD be maintained (but currently may not
be):
+ # P0: pooled => enabled /\ ready
+ # P1: up => pooled \/ !enabled \/ !ready
+ # P2: pooled => up \/ !canDepool
+
+ self.weight = self.DEF_WEIGHT
+ self.up = False
+ self.pooled = False
+ self.enabled = True
+ self.ready = False
+ self.modified = None
+
+ def __eq__(self, other):
+ return isinstance(other, Server) and self.host == other.host and
self.lvsservice == other.lvsservice
+
+ def __hash__(self):
+ return hash(self.host)
+
+ def addMonitor(self, monitor):
+ """Adds a monitor instance to the set"""
+
+ self.monitors.add(monitor)
+
+ def removeMonitors(self):
+ """Removes all monitors"""
+
+ for monitor in self.monitors:
+ monitor.stop()
+
+ self.monitors.clear()
+
+ def resolveHostname(self):
+ """Attempts to resolve the server's hostname to an IP address for
better reliability."""
+
+ timeout = [1, 2, 5]
+ lookups = []
+
+ query = dns.Query(self.host, dns.A)
+ lookups.append(client.lookupAddress(self.host, timeout
+ ).addCallback(self._lookupFinished, socket.AF_INET, query))
+
+ query = dns.Query(self.host, dns.AAAA)
+ lookups.append(client.lookupIPV6Address(self.host, timeout
+ ).addCallback(self._lookupFinished, socket.AF_INET6, query))
+
+ return defer.DeferredList(lookups).addBoth(self._hostnameResolved)
+
+ def _lookupFinished(self, (answers, authority, additional), addressFamily,
query):
+ ips = set([socket.inet_ntop(addressFamily, r.payload.address)
+ for r in answers
+ if r.name == query.name and r.type == query.type])
+
+ if query.type == dns.A:
+ self.ip4_addresses = ips
+ elif query.type == dns.AAAA:
+ self.ip6_addresses = ips
+
+ # TODO: expire TTL
+ #if self.ip:
+ # minTTL = min([r.ttl for r in answers
+ # if r.name == query.name and r.type == query.type])
+
+ return ips
+
+ def _hostnameResolved(self, result):
+ # Pick *1* main ip address to use. Prefer any existing one
+ # if still available.
+
+ addr = " ".join(
+ list(self.ip4_addresses) + list(self.ip6_addresses))
+ msg = "Resolved {} to addresses {}".format(self.host, addr)
+ log.debug(msg)
+
+ ip_addresses = {
+ socket.AF_INET:
+ self.ip4_addresses,
+ socket.AF_INET6:
+ self.ip6_addresses
+ }[self.addressFamily]
+
+ try:
+ if not self.ip or self.ip not in ip_addresses:
+ self.ip = random.choice(list(ip_addresses))
+ # TODO: (re)pool
+ except IndexError:
+ return failure.Failure() # TODO: be more specific?
+ else:
+ return True
+
+ def destroy(self):
+ self.enabled = False
+ self.removeMonitors()
+
+ def initialize(self, coordinator):
+ """
+ Initializes this server instance and fires a Deferred
+ when ready for use (self.ready == True)
+ """
+
+ d = self.resolveHostname()
+
+ return d.addCallbacks(self._ready, self._initFailed,
callbackArgs=[coordinator])
+
+ def _ready(self, result, coordinator):
+ """
+ Called when initialization has finished.
+ """
+
+ self.ready = True
+ self.up = self.DEF_STATE
+ self.pooled = self.DEF_STATE
+ self.maintainState()
+
+ self.createMonitoringInstances(coordinator)
+
+ return True
+
+ def _initFailed(self, fail):
+ """
+ Called when initialization failed
+ """
+ log.error("Initialization failed for server {}".format(self.host))
+
+ assert self.ready == False
+ self.maintainState()
+
+ return False # Continue on success callback chain
+
+ def createMonitoringInstances(self, coordinator):
+ """Creates and runs monitoring instances for this Server"""
+
+ lvsservice = self.lvsservice
+
+ try:
+ monitorlist = eval(lvsservice.configuration['monitors'])
+ except KeyError:
+ log.critical(
+ "LVS service {} does not have a 'monitors' configuration
option set.".format(
+ lvsservice.name)
+ )
+ raise
+
+ if type(monitorlist) != list:
+ msg = "option 'monitors' in LVS service section {} is not a python
list"
+ log.err(msg.format(lvsservice.name))
+ else:
+ for monitorname in monitorlist:
+ try:
+ monitormodule = importlib.import_module(
+ "pybal.monitors.{}".format(monitorname.lower()))
+ except ImportError:
+ log.err("Monitor {} does not exist".format(monitorname))
+ except Exception:
+ log.critical("Cannot import
pybal.monitors.{}".format(monitorname))
+ # An exception was raised importing the given monitor
+ # module. Instead of just logging the problem, stop PyBal
+ # as the admin might think everything is fine and all
+ # checks are green, while in fact no check is being
+ # performed.
+ reactor.stop()
+ else:
+ monitorclass = getattr(monitormodule, monitorname +
'MonitoringProtocol')
+ monitor = monitorclass(coordinator, self,
lvsservice.configuration)
+ self.addMonitor(monitor)
+ monitor.run()
+
+ def calcStatus(self):
+ """AND quantification of monitor.up over all monitoring instances of a
single Server"""
+
+ # Global status is up iff all monitors report up
+ return reduce(lambda b,monitor: b and monitor.up, self.monitors,
len(self.monitors) != 0)
+
+ def calcPartialStatus(self):
+ """OR quantification of monitor.up over all monitoring instances of a
single Server"""
+
+ # Partial status is up iff one of the monitors reports up
+ return reduce(lambda b,monitor: b or monitor.up, self.monitors,
len(self.monitors) == 0)
+
+ def textStatus(self):
+ return "%s/%s/%s" % (self.enabled and "enabled" or "disabled",
+ self.up and "up" or (self.calcPartialStatus() and
"partially up" or "down"),
+ self.pooled and "pooled" or "not pooled")
+
+ def maintainState(self):
+ """Maintains a few invariants on configuration changes"""
+
+ # P0
+ if not self.enabled or not self.ready:
+ self.pooled = False
+ # P1
+ if not self.pooled and self.enabled:
+ self.up = False
+
+ def merge(self, configuration):
+ """Merges in configuration from a dictionary of (allowed) attributes"""
+
+ for key, value in configuration.iteritems():
+ if (key, type(value)) not in self.allowedConfigKeys:
+ del configuration[key]
+
+ # Overwrite configuration
+ self.__dict__.update(configuration)
+ self.maintainState()
+ self.modified = True # Indicate that this instance previously
existed
+
+ def dumpState(self):
+ """Dump current state of the server"""
+ return {'pooled': self.pooled, 'weight': self.weight,
+ 'up': self.up, 'enabled': self.enabled}
+
+ @classmethod
+ def buildServer(cls, hostName, configuration, lvsservice):
+ """
+ Factory method which builds a Server instance from a
+ dictionary of (allowed) configuration attributes
+ """
+
+ server = cls(hostName, lvsservice) # create a new instance...
+ server.merge(configuration) # ...and override attributes
+ server.modified = False
+
+ return server
diff --git a/pybal/test/test_coordinator.py b/pybal/test/test_coordinator.py
index 35cede6..b6ab1a9 100644
--- a/pybal/test/test_coordinator.py
+++ b/pybal/test/test_coordinator.py
@@ -9,6 +9,7 @@
import mock
import pybal.coordinator
+import pybal.server
import pybal.util
from twisted.internet.reactor import getDelayedCalls
@@ -30,7 +31,7 @@
self.coordinator.lvsservice.getDepoolThreshold = mock.MagicMock(
return_value=0.5)
- pybal.coordinator.Server.initialize = mock.MagicMock()
+ pybal.server.Server.initialize = mock.MagicMock()
def tearDown(self):
self.coordinator.configObserver.reloadTask.stop()
diff --git a/pybal/test/test_server.py b/pybal/test/test_server.py
index 3eefca4..01da0d9 100644
--- a/pybal/test/test_server.py
+++ b/pybal/test/test_server.py
@@ -3,7 +3,7 @@
PyBal unit tests
~~~~~~~~~~~~~~~~
- This module contains tests for `pybal.coordinator.Server`.
+ This module contains tests for `pybal.server.Server`.
"""
@@ -17,12 +17,12 @@
from .fixtures import PyBalTestCase
class ServerTestCase(PyBalTestCase):
- """Test case for `pybal.coordinator.Server`."""
+ """Test case for `pybal.server.Server`."""
def setUp(self):
super(ServerTestCase, self).setUp()
- self.server = pybal.coordinator.Server(
+ self.server = pybal.server.Server(
'example.com', mock.MagicMock())
self.mockMonitor = mock.MagicMock()
@@ -124,5 +124,5 @@
hostName=self.exampleConfigDict['host'],
configuration=self.exampleConfigDict,
lvsservice=mock.MagicMock())
- self.assertTrue(isinstance(server, pybal.coordinator.Server))
+ self.assertTrue(isinstance(server, pybal.server.Server))
self.assertFalse(server.modified)
--
To view, visit https://gerrit.wikimedia.org/r/404713
To unsubscribe, visit https://gerrit.wikimedia.org/r/settings
Gerrit-MessageType: merged
Gerrit-Change-Id: I925f0abe553cd82603014cd8a0760be8bc8ad880
Gerrit-PatchSet: 1
Gerrit-Project: operations/debs/pybal
Gerrit-Branch: master
Gerrit-Owner: Mark Bergsma <[email protected]>
Gerrit-Reviewer: Ema <[email protected]>
Gerrit-Reviewer: Giuseppe Lavagetto <[email protected]>
Gerrit-Reviewer: Volans <[email protected]>
Gerrit-Reviewer: jenkins-bot <>
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