chaos_lib.py

from __future__ import division, unicode_literals

import sys
sys.path.insert(0, '/opt/python/.vendor')

from ssm_cache import SSMParameter
import time
import random
import json
import requests


def get_config():
    param = SSMParameter('chaoslambda.config')
    try:
        value = json.loads(param.value)
        delay = value["delay"]
        isEnabled = value["isEnabled"]
        if isEnabled and delay > 0:
            return delay
        elif isEnabled and delay <= 0:
            return -1
        else:
            return 0
    except Exception as e:
        print(e)
        return 0


def delayit(method):
    def latency(*args, **kw):
        delay = get_config()
        start = time.time()
        # if delay exist, delaying with that value
        if delay > 0:
            time.sleep(delay / 1000.0)
        # if delay = -1 make random delays
        elif delay < 0:
            # add latency approx 50% of the time
            if random.random() > 0.5:
                # random sleep time between 1 and 10 seconds
                time.sleep(random.randint(1, 10))
        else:
            pass

        result = method(*args, **kw)
        end = time.time()

        print('Added {1:.2f}ms to {0:s}'.format(
            method.__name__,
            (end - start) * 1000
        ))

        return result
    return latency


class SessionWithDelay(requests.Session):
    def __init__(self, delay=None, *args, **kwargs):
        super(SessionWithDelay, self).__init__(*args, **kwargs)
        self.delay = delay

    def request(self, method, url, **kwargs):
        print('Added {}ms of delay'.format(self.delay))
        time.sleep(self.delay / 1000.0)
        return super(SessionWithDelay, self).request(method, url, **kwargs)