75 lines
2.2 KiB
Python
75 lines
2.2 KiB
Python
# Copyright 2017 Canonical Limited.
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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import os
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import json
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from charmhelpers.core.hookenv import log
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stats_intervals = ['stats_day', 'stats_five_minute',
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'stats_hour', 'stats_total']
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SYSFS = '/sys'
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class Bcache(object):
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"""Bcache behaviour
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"""
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def __init__(self, cachepath):
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self.cachepath = cachepath
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@classmethod
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def fromdevice(cls, devname):
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return cls('{}/block/{}/bcache'.format(SYSFS, devname))
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def __str__(self):
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return self.cachepath
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def get_stats(self, interval):
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"""Get cache stats
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"""
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intervaldir = 'stats_{}'.format(interval)
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path = "{}/{}".format(self.cachepath, intervaldir)
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out = dict()
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for elem in os.listdir(path):
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out[elem] = open('{}/{}'.format(path, elem)).read().strip()
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return out
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def get_bcache_fs():
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"""Return all cache sets
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"""
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cachesetroot = "{}/fs/bcache".format(SYSFS)
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try:
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dirs = os.listdir(cachesetroot)
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except OSError:
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log("No bcache fs found")
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return []
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cacheset = set([Bcache('{}/{}'.format(cachesetroot, d)) for d in dirs if not d.startswith('register')])
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return cacheset
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def get_stats_action(cachespec, interval):
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"""Action for getting bcache statistics for a given cachespec.
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Cachespec can either be a device name, eg. 'sdb', which will retrieve
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cache stats for the given device, or 'global', which will retrieve stats
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for all cachesets
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"""
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if cachespec == 'global':
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caches = get_bcache_fs()
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else:
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caches = [Bcache.fromdevice(cachespec)]
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res = dict((c.cachepath, c.get_stats(interval)) for c in caches)
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return json.dumps(res, indent=4, separators=(',', ': '))
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