Measure datadog latency using datadog

redirect-timing.py

"""Measures redirect latency from http://app.datadoghq.com to login.

Use like this: curl -L -v http://app.datadoghq.com --trace-time 2>&1 | python redirect-timing.py
"""
import sys
from datetime import datetime, time
import time as t2
import re
from dogapi import dog_http_api
from ConfigParser import ConfigParser
import os
# import logging; logging.basicConfig(level=logging.DEBUG)

# Assumes dog is configured
cfg = ConfigParser()
cfg.read(os.path.join(os.environ["HOME"], ".dogrc"))
dog_http_api.api_key = cfg.get("Connection", "apikey")
dog_http_api.application_key = cfg.get("Connection", "appkey")

TS_RE = re.compile(r"^(\d{2}:\d{2}:\d{2}.\d{6})")
REQ_RE = re.compile(r"request to this URL")

first_line = True
convert = lambda s: datetime.strptime(s, "%H:%M:%S.%f")
to_ms = lambda td: td.seconds * 1000.0 + td.microseconds / 1000.0
reqs = []

start = t2.time()

while True:
    line = sys.stdin.readline()
    if line is None or len(line) == 0:
        # Done, print results
        break

    line = line.strip()

    # Get start of experiment
    if first_line:
        m = TS_RE.match(line)
        assert m, line
        reqs.append((convert(m.group(1)), None))
        first_line = False
        continue

    m = REQ_RE.search(line)
    if m:
        elements = line.split()
        ts = convert(elements[0])
        url = elements[-1][1:-1]
        reqs.append((ts, url))
    
# Finally substract reqs[1:] from its predecessor
results = [(to_ms(reqs[i][0] - reqs[i-1][0]), reqs[i][1]) for i in range(1, len(reqs))]
for duration, url in results:
    dog_http_api.metric("datadog.net.redirect", (start, duration), tags=["url:{0}".format(url)])