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@unicolet unicolet/ratelimit.py
Last active May 10, 2016

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Warning: crude hack ahead! Implement a rate limiting state module for SaltStack reactors. State is maintained in a sqlite database.
import salt.exceptions
import logging
import time
__name__ = 'ratelimit'
log = logging.getLogger(__name__)
def event(name, event_in, event_out):
bucket = {}
forward = False
ret = {'event_in': event_in, 'changes': {}, 'result': False, 'comment': '', 'name': __name__}
rate = 1.0; # unit: event
per = 30.0; # unit: seconds
results = __salt__['sqlite3.fetch']('/etc/salt/rl.db',"select k,allowance,last_check from rl where k='{0}'".format(event_in))
if len(results) == 1:
bucket=results[0]
log.debug(str(bucket))
if bucket:
allowance = bucket[1]
last_check = bucket[2]
log.debug('event key found in bucket')
else:
last_check = int(time.time()); # floating-point, e.g. usec accuracy. Unit: seconds
allowance = rate; # unit: event
log.debug('event key NOT found in bucket')
log.debug('BEGIN allowance={0} last_check={1}'.format(allowance,last_check))
current = int(time.time());
time_passed = current - last_check;
last_check = current;
allowance += time_passed * (rate / per);
if (allowance > rate):
allowance = rate; # throttle
ret['comment'] = 'Event "{0}" throttled'.format(event_in)
if (allowance < 1.0):
log.debug(__name__ + 'rate limiting event: '+str(event_in))
ret['comment'] = 'Event "{0}" rate limited'.format(event_in)
else:
log.debug('forwarding event: '+str(event_in)+' as '+str(event_out))
ret['comment'] = 'Event "{0}" forwarded'.format(event_in)
allowance -= 1.0;
forward = True
log.debug('END allowance={0} last_check={1}'.format(allowance,last_check))
if not bucket:
__salt__['sqlite3.modify']('/etc/salt/rl.db',"insert into rl (k,allowance,last_check) values ('{0}',{1},{2})".format(event_in, allowance, last_check))
else:
__salt__['sqlite3.modify']('/etc/salt/rl.db',"update rl set allowance={1},last_check={2} where k='{0}'".format(event_in, allowance, last_check))
ret['result'] = forward
if forward:
__salt__['event.send'](event_out, ret)
return ret
ratelimit_db:
module.run:
- name: sqlite3.modify
- db: /etc/salt/rl.db
- sql: create table rl(k varchar PRIMARY KEY, allowance bigint, last_check bigint);
- unless:
- ls /etc/salt/rl.db
rate_limit_events:
ratelimit.event:
- event_in: {{ pillar['event_in'] }}
- event_out: {{ pillar['event_out'] }}
rate_limit:
local.state.sls:
- tgt: master
- arg:
- ratelimit
- kwarg:
pillar:
event_in: {{ data['tag'] }}
event_out: ratelimited/{{data['tag']}}
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