| # Copyright (C) 2019 Apple Inc. All rights reserved. |
| # |
| # Redistribution and use in source and binary forms, with or without |
| # modification, are permitted provided that the following conditions |
| # are met: |
| # 1. Redistributions of source code must retain the above copyright |
| # notice, this list of conditions and the following disclaimer. |
| # 2. Redistributions in binary form must reproduce the above copyright |
| # notice, this list of conditions and the following disclaimer in the |
| # documentation and/or other materials provided with the distribution. |
| # |
| # THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS "AS IS" AND |
| # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED |
| # WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
| # DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR |
| # ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR |
| # SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER |
| # CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
| # OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
| import random |
| import requests |
| import threading |
| import time |
| |
| from redis import StrictRedis |
| |
| |
| class CasseroleNodes(object): |
| DEFAULT_INTERVAL = 120 # Refresh every 2 minutes |
| |
| def __init__(self, url, interval_seconds=DEFAULT_INTERVAL, asynchronous=True): |
| self.url = url |
| self.interval = interval_seconds |
| self._epoch = 0 |
| self.asynchronous = asynchronous |
| self._nodes = [] |
| self.retrieve_nodes() |
| if not self._nodes: |
| raise RuntimeError(f'Cannot communicate with Casserole url {self.url}') |
| |
| def retrieve_nodes(self): |
| casserole_response = requests.get(self.url) |
| if casserole_response.status_code != 200: |
| return |
| self._epoch = time.time() |
| self._nodes = casserole_response.text.split(',') |
| |
| @property |
| def nodes(self): |
| if self._epoch + self.interval > time.time(): |
| return self._nodes |
| |
| if self.asynchronous: |
| request_thread = threading.Thread(target=self.retrieve_nodes) |
| request_thread.daemon = True |
| request_thread.start() |
| else: |
| self.retrieve_nodes() |
| return self._nodes |
| |
| def __len__(self): |
| return len(self.nodes) |
| |
| def __iter__(self): |
| return iter(self.nodes) |
| |
| |
| class CasseroleRedis(object): |
| DEFAULT_INTERVAL = 120 # Refresh every 2 minutes |
| |
| def __init__( |
| self, url, port=6379, password=None, interval_seconds=DEFAULT_INTERVAL, asynchronous=True, |
| ssl_keyfile=None, ssl_certfile=None, ssl_cert_reqs='required', ssl_ca_certs=None, |
| ): |
| self.url = url |
| self.interval = interval_seconds |
| self.asynchronous = asynchronous |
| |
| self._redis = None |
| self._redis_url = None |
| self._redis_kwargs = dict( |
| port=port, |
| password=password, |
| ssl_keyfile=ssl_keyfile, |
| ssl_certfile=ssl_certfile, |
| ssl_cert_reqs=ssl_cert_reqs, |
| ssl_ca_certs=ssl_ca_certs, |
| ) |
| |
| self._epoch = time.time() |
| self.connect() |
| |
| def connect(self): |
| if self._redis and self._epoch + self.interval > time.time(): |
| return |
| |
| def do_connection(obj=self): |
| casserole_response = requests.get(obj.url) |
| if casserole_response.status_code != 200: |
| return |
| |
| candidates = {} |
| for candidate in casserole_response.json(): |
| if not candidate['isMaster']: |
| continue |
| candidates[candidate['host']] = candidate |
| if self._redis and self._redis_url in candidates: |
| # We're still connected, we don't need to do anything |
| return |
| |
| self._redis_url = random.choice(list(candidates.keys())) |
| port = candidates[self._redis_url].get('sslPort') |
| kwargs = dict(**self._redis_kwargs) |
| kwargs['port'] = port or kwargs['port'] |
| |
| self._redis = StrictRedis( |
| host=self._redis_url, |
| ssl=True if port else False, |
| **kwargs |
| ) |
| |
| obj._epoch = time.time() |
| |
| if self.asynchronous and self._redis: |
| request_thread = threading.Thread(target=do_connection) |
| request_thread.daemon = True |
| request_thread.start() |
| else: |
| do_connection() |
| |
| def ping(self): |
| self.connect() |
| return self._redis.ping() |
| |
| def get(self, name): |
| self.connect() |
| return self._redis.get(name) |
| |
| def set(self, *args, **kwargs): |
| self.connect() |
| return self._redis.set(*args, **kwargs) |
| |
| def lock(self, name, **kwargs): |
| self.connect() |
| return self._redis.lock(name, **kwargs) |
| |
| def delete(self, *names): |
| self.connect() |
| return self._redis.delete(*names) |
| |
| def scan_iter(self, match=None, **kwargs): |
| self.connect() |
| return self._redis.scan_iter(match=match, **kwargs) |