Files
patroni/tests/test_etcd.py
T
Alexander KukushkinandGitHub 19c80df442 Try to mitigate EtcdEventIndexCleared exception (#287)
This error is send by etcd when Patroni is doing "watch" on leader key
which is never updated after creation and etcd cluster receives a lot of
updates, what cleans history of events.

Instead of doing watch on modifiedIndex + 1 we will do watch on X-Etcd-Index,
which is probably still available...
2016-09-02 13:44:47 +02:00

286 lines
11 KiB
Python

import etcd
import json
import requests
import socket
import unittest
from dns.exception import DNSException
from mock import Mock, patch
from patroni.dcs.etcd import AbstractDCS, Client, Cluster, Etcd, EtcdError
from patroni.exceptions import DCSError
from urllib3.exceptions import ReadTimeoutError
class MockResponse(object):
def __init__(self, status_code=200):
self.status_code = status_code
self.content = '{}'
self.ok = True
self.text = ''
def json(self):
return json.loads(self.content)
@property
def data(self):
return self.content.encode('utf-8')
@property
def status(self):
return self.status_code
@staticmethod
def getheader(*args):
return ''
def requests_get(url, **kwargs):
members = '[{"id":14855829450254237642,"peerURLs":["http://localhost:2380","http://localhost:7001"],' +\
'"name":"default","clientURLs":["http://localhost:2379","http://localhost:4001"]}]'
response = MockResponse()
if url.startswith('http://local'):
raise requests.exceptions.RequestException()
elif ':8011/patroni' in url:
response.content = '{"role": "replica", "xlog": {"replayed_location": 0}, "tags": {}}'
elif url.endswith('/members'):
response.content = '[{}]' if url.startswith('http://error') else members
elif url.startswith('http://exhibitor'):
response.content = '{"servers":["127.0.0.1","127.0.0.2","127.0.0.3"],"port":2181}'
else:
response.status_code = 404
response.ok = False
return response
def etcd_watch(self, key, index=None, timeout=None, recursive=None):
if timeout == 2.0:
raise etcd.EtcdWatchTimedOut
elif timeout == 5.0:
return etcd.EtcdResult('delete', {})
elif timeout == 10.0:
raise etcd.EtcdException
def etcd_write(self, key, value, **kwargs):
if key == '/service/exists/leader':
raise etcd.EtcdAlreadyExist
if key in ['/service/test/leader', '/patroni/test/leader'] and \
(kwargs.get('prevValue') == 'foo' or not kwargs.get('prevExist', True)):
return True
raise etcd.EtcdException
def etcd_read(self, key, **kwargs):
if key == '/service/noleader/':
raise DCSError('noleader')
elif key == '/service/nocluster/':
raise etcd.EtcdKeyNotFound
response = {"action": "get", "node": {"key": "/service/batman5", "dir": True, "nodes": [
{"key": "/service/batman5/config", "value": '{"foo": "bar"}',
"modifiedIndex": 1582, "createdIndex": 1582},
{"key": "/service/batman5/failover", "value": "",
"modifiedIndex": 1582, "createdIndex": 1582},
{"key": "/service/batman5/initialize", "value": "postgresql0",
"modifiedIndex": 1582, "createdIndex": 1582},
{"key": "/service/batman5/leader", "value": "postgresql1",
"expiration": "2015-05-15T09:11:00.037397538Z", "ttl": 21,
"modifiedIndex": 20728, "createdIndex": 20434},
{"key": "/service/batman5/optime", "dir": True, "nodes": [
{"key": "/service/batman5/optime/leader", "value": "2164261704",
"modifiedIndex": 20729, "createdIndex": 20729}],
"modifiedIndex": 20437, "createdIndex": 20437},
{"key": "/service/batman5/members", "dir": True, "nodes": [
{"key": "/service/batman5/members/postgresql1",
"value": "postgres://replicator:[email protected]:5434/postgres" +
"?application_name=http://127.0.0.1:8009/patroni",
"expiration": "2015-05-15T09:10:59.949384522Z", "ttl": 21,
"modifiedIndex": 20727, "createdIndex": 20727},
{"key": "/service/batman5/members/postgresql0",
"value": "postgres://replicator:[email protected]:5433/postgres" +
"?application_name=http://127.0.0.1:8008/patroni",
"expiration": "2015-05-15T09:11:09.611860899Z", "ttl": 30,
"modifiedIndex": 20730, "createdIndex": 20730}],
"modifiedIndex": 1581, "createdIndex": 1581}], "modifiedIndex": 1581, "createdIndex": 1581}}
result = etcd.EtcdResult(**response)
result.etcd_index = 0
return result
class SleepException(Exception):
pass
class MockSRV(object):
port = 2380
target = '127.0.0.1'
def dns_query(name, _):
if name == '_etcd-server._tcp.blabla':
return []
elif name == '_etcd-server._tcp.exception':
raise DNSException()
return [MockSRV()]
def socket_getaddrinfo(*args):
if args[0] == 'ok':
return [(2, 1, 6, '', ('127.0.0.1', 2379)), (2, 1, 6, '', ('127.0.0.1', 2379))]
raise socket.error
def http_request(method, url, **kwargs):
if url == 'http://localhost:2379/timeout':
raise ReadTimeoutError(None, None, None)
if url == 'http://localhost:2379/v2/machines':
ret = MockResponse()
ret.content = 'http://localhost:2379,http://localhost:4001'
return ret
if url == 'http://localhost:2379/':
return MockResponse()
raise socket.error
@patch('dns.resolver.query', dns_query)
@patch('socket.getaddrinfo', socket_getaddrinfo)
@patch('requests.get', requests_get)
class TestClient(unittest.TestCase):
@patch('dns.resolver.query', dns_query)
@patch('requests.get', requests_get)
def setUp(self):
with patch.object(Client, 'machines') as mock_machines:
mock_machines.__get__ = Mock(return_value=['http://localhost:2379', 'http://localhost:4001'])
self.client = Client({'discovery_srv': 'test', 'retry_timeout': 3})
self.client.http.request = http_request
self.client.http.request_encode_body = http_request
def test_machines(self):
self.client._base_uri = 'http://localhost:4001'
self.client._machines_cache = ['http://localhost:2379']
self.assertIsNotNone(self.client.machines)
self.client._base_uri = 'http://localhost:4001'
self.client._machines_cache = []
self.assertIsNotNone(self.client.machines)
self.client._update_machines_cache = True
machines = None
try:
machines = self.client.machines
self.assertFail()
except Exception:
self.assertIsNone(machines)
@patch.object(Client, 'machines')
def test_api_execute(self, mock_machines):
mock_machines.__get__ = Mock(return_value=['http://localhost:2379'])
self.assertRaises(ValueError, self.client.api_execute, '', '')
self.client._base_uri = 'http://localhost:4001'
self.client._machines_cache = ['http://localhost:2379']
self.client.api_execute('/', 'POST', timeout=0)
self.assertRaises(etcd.EtcdWatchTimedOut, self.client.api_execute, '/timeout', 'POST', params={'wait': 'true'})
self.assertRaises(etcd.EtcdException, self.client.api_execute, '/', '')
self.client._update_machines_cache = True
with patch.object(Client, '_load_machines_cache', Mock(side_effect=etcd.EtcdException)):
self.assertRaises(etcd.EtcdException, self.client.api_execute, '/', 'GET')
def test_get_srv_record(self):
self.assertEquals(self.client.get_srv_record('blabla'), [])
self.assertEquals(self.client.get_srv_record('exception'), [])
def test__get_machines_cache_from_srv(self):
self.client.get_srv_record = Mock(return_value=[('localhost', 2380)])
self.client._get_machines_cache_from_srv('blabla')
def test__get_machines_cache_from_dns(self):
self.client._get_machines_cache_from_dns('error:2379')
@patch.object(Client, 'machines')
def test__load_machines_cache(self, mock_machines):
mock_machines.__get__ = Mock(return_value=['http://localhost:2379'])
self.client._config = {}
self.assertRaises(Exception, self.client._load_machines_cache)
self.client._config = {'discovery_srv': 'blabla'}
self.assertRaises(etcd.EtcdException, self.client._load_machines_cache)
@patch('requests.get', requests_get)
@patch.object(etcd.Client, 'write', etcd_write)
@patch.object(etcd.Client, 'read', etcd_read)
@patch.object(etcd.Client, 'delete', Mock(side_effect=etcd.EtcdException))
class TestEtcd(unittest.TestCase):
def setUp(self):
with patch.object(Client, 'machines') as mock_machines:
mock_machines.__get__ = Mock(return_value=['http://localhost:2379', 'http://localhost:4001'])
self.etcd = Etcd({'namespace': '/patroni/', 'ttl': 30, 'retry_timeout': 10,
'host': 'localhost:2379', 'scope': 'test', 'name': 'foo'})
def test_base_path(self):
self.assertEquals(self.etcd._base_path, '/patroni/test')
@patch('dns.resolver.query', dns_query)
def test_get_etcd_client(self):
with patch.object(Client, 'machines') as mock_machines:
mock_machines.__get__ = Mock(side_effect=etcd.EtcdException)
with patch('time.sleep', Mock(side_effect=SleepException)):
self.assertRaises(SleepException, self.etcd.get_etcd_client,
{'discovery_srv': 'test', 'retry_timeout': 10})
def test_get_cluster(self):
self.assertIsInstance(self.etcd.get_cluster(), Cluster)
self.etcd._base_path = '/service/nocluster'
cluster = self.etcd.get_cluster()
self.assertIsInstance(cluster, Cluster)
self.assertIsNone(cluster.leader)
self.etcd._base_path = '/service/noleader'
self.assertRaises(EtcdError, self.etcd.get_cluster)
def test_touch_member(self):
self.assertFalse(self.etcd.touch_member('', ''))
def test_take_leader(self):
self.assertFalse(self.etcd.take_leader())
def test_attempt_to_acquire_leader(self):
self.etcd._base_path = '/service/exists'
self.assertFalse(self.etcd.attempt_to_acquire_leader())
self.etcd._base_path = '/service/failed'
self.assertFalse(self.etcd.attempt_to_acquire_leader())
def test_write_leader_optime(self):
self.etcd.write_leader_optime('0')
def test_update_leader(self):
self.assertTrue(self.etcd.update_leader())
def test_initialize(self):
self.assertFalse(self.etcd.initialize())
def test_cancel_initializion(self):
self.assertFalse(self.etcd.cancel_initialization())
def test_delete_leader(self):
self.assertFalse(self.etcd.delete_leader())
def test_delete_cluster(self):
self.assertFalse(self.etcd.delete_cluster())
@patch.object(etcd.Client, 'watch', etcd_watch)
def test_watch(self):
self.etcd.watch(0)
self.etcd.get_cluster()
self.etcd.watch(1.5)
self.etcd.watch(4.5)
with patch.object(AbstractDCS, 'watch', Mock()):
self.etcd.watch(9.5)
def test_other_exceptions(self):
self.etcd.retry = Mock(side_effect=AttributeError('foo'))
self.assertRaises(EtcdError, self.etcd.cancel_initialization)
def test_set_ttl(self):
self.etcd.set_ttl(20)
self.assertTrue(self.etcd.watch(1))