# Copyright 2016 Palo Alto Networks, Inc
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""
This module implements the writer class for logs
"""
import logging
import psutil
import ujson
import gevent
import gevent.event
LOG = logging.getLogger(__name__)
class DiskSpaceMonitor(gevent.Greenlet):
def __init__(self, threshold, low_disk):
self._threshold = threshold
self._low_disk = low_disk
super(DiskSpaceMonitor, self).__init__()
def _run(self):
while True:
perc_used = psutil.disk_usage('.').percent
if perc_used >= self._threshold:
if not self._low_disk.is_set():
self._low_disk.set()
LOG.critical(
'Disk space used above threshold ({}%), writing disabled'.format(self._threshold)
)
else:
if self._low_disk.is_set():
self._low_disk.clear()
LOG.info('Disk space used below threshold, writing restored')
gevent.sleep(60)
class Writer(object):
def __init__(self, comm, store, topic, config):
self._stop = gevent.event.Event()
self._low_disk = gevent.event.Event()
self.store = store
self.comm = comm
self.comm.request_sub_channel(
topic,
self,
allowed_methods=['log'],
name='mbus:log:writer',
multi_write=True
)
self._disk_monitor_glet = DiskSpaceMonitor(
threshold=config.get('threshold', 70),
low_disk=self._low_disk
)
self._disk_monitor_glet.start()
def log(self, timestamp, **kwargs):
if self._stop.is_set():
return
if self._low_disk.is_set():
return
self.store.write(timestamp, ujson.dumps(kwargs))
def stop(self):
LOG.info('Writer - stop called')
if self._stop.is_set():
return
self._stop.set()
self._disk_monitor_glet.kill()
