qinling/runtimes/python3/cglimit.py
heychirag b3196b27a2 python3 runtime
Created a new runtime for python3 taking clues from the available python2
runtime. The runtime has been tested on various test functions.

Change-Id: Iccf3360ea5a389a7dfa2b091979c5713062fa73a
Task: 22199
Story: 2002590
2018-08-01 14:25:47 +02:00

125 lines
4.3 KiB
Python

# Copyright 2018 Catalyst IT Limited
#
# 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.
import logging
import os
import sys
from flask import Flask
from flask import make_response
from flask import request
from oslo_concurrency import lockutils
app = Flask(__name__)
ch = logging.StreamHandler(sys.stdout)
ch.setLevel(logging.DEBUG)
ch.setFormatter(logging.Formatter('%(asctime)s - %(levelname)s - %(message)s'))
del app.logger.handlers[:]
app.logger.addHandler(ch)
# Deployer can specify cfs_period_us default value here.
PERIOD = 100000
def log(message, level="info"):
global app
log_func = getattr(app.logger, level)
log_func(message)
@lockutils.synchronized('set_limitation', external=True,
lock_path='/var/lock/qinling')
def _cgroup_limit(cpu, memory_size, pid):
"""Modify 'cgroup' files to set resource limits.
Each pod(worker) will have cgroup folders on the host cgroup filesystem,
like '/sys/fs/cgroup/<resource_type>/kubepods/<qos_class>/pod<pod_id>/',
to limit memory and cpu resources that can be used in pod.
For more information about cgroup, please see [1], about sharing PID
namespaces in kubernetes, please see also [2].
Return None if successful otherwise a Flask.Response object.
[1]https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/6/html/resource_management_guide/sec-creating_cgroups
[2]https://github.com/kubernetes/kubernetes/pull/51634
"""
hostname = os.getenv('HOSTNAME')
pod_id = os.getenv('POD_UID')
qos_class = None
if os.getenv('QOS_CLASS') == 'BestEffort':
qos_class = 'besteffort'
elif os.getenv('QOS_CLASS') == 'Burstable':
qos_class = 'burstable'
elif os.getenv('QOS_CLASS') == 'Guaranteed':
qos_class = ''
if not pod_id or qos_class is None:
return make_response("Failed to get current worker information", 500)
memory_base_path = os.path.join('/qinling_cgroup', 'memory', 'kubepods',
qos_class, 'pod%s' % pod_id)
cpu_base_path = os.path.join('/qinling_cgroup', 'cpu', 'kubepods',
qos_class, 'pod%s' % pod_id)
memory_path = os.path.join(memory_base_path, hostname)
cpu_path = os.path.join(cpu_base_path, hostname)
if os.path.isdir(memory_base_path):
if not os.path.isdir(memory_path):
os.makedirs(memory_path)
if os.path.isdir(cpu_base_path):
if not os.path.isdir(cpu_path):
os.makedirs(cpu_path)
try:
# set cpu and memory resource limits
with open('%s/memory.limit_in_bytes' % memory_path, 'w') as f:
f.write('%d' % int(memory_size))
with open('%s/cpu.cfs_period_us' % cpu_path, 'w') as f:
f.write('%d' % PERIOD)
with open('%s/cpu.cfs_quota_us' % cpu_path, 'w') as f:
f.write('%d' % ((int(cpu)*PERIOD/1000)))
# add pid to 'tasks' files
with open('%s/tasks' % memory_path, 'w') as f:
f.write('%d' % pid)
with open('%s/tasks' % cpu_path, 'w') as f:
f.write('%d' % pid)
except Exception as e:
return make_response("Failed to modify cgroup files: %s"
% str(e), 500)
@app.route('/cglimit', methods=['POST'])
def cglimit():
"""Set resource limitations for execution.
Only root user has jurisdiction to modify all cgroup files.
:param cpu: cpu resource that execution can use in total.
:param memory_size: RAM resource that execution can use in total.
Currently swap ought to be disabled in kubernetes.
"""
params = request.get_json()
cpu = params['cpu']
memory_size = params['memory_size']
pid = params['pid']
log("Set resource limits request received, params: %s" % params)
resp = _cgroup_limit(cpu, memory_size, pid)
return resp if resp else 'pidlimited'