detect-exceptions

#!/usr/bin/env python

import sys
import time
import json
import threading
import signal
import optparse

exceptions = {}
in_exception = False
exception_lines = []
running_lock = threading.Lock()

parser = optparse.OptionParser(usage="Usage: %prog [options]")

parser.add_option('-n', '--namespace', action="store", dest="ns", help="ns parameter of the json output.")
parser.add_option('-i', '--interval', action="store", dest="interval",
                  help="How often (in seconds) should flush exceptions.", default=5)

options, args = parser.parse_args()

def exception_ended():
    global in_exception, exception_lines, running_lock
    exception_string = "\n".join(exception_lines)
    running_lock.acquire(True)
    try:
        exceptions[exception_string] = exceptions.get(exception_string, 0) + 1
    finally:
        running_lock.release()

    exception_lines = []
    in_exception = False

def process_input():
    global in_exception, exception_lines
    for line in sys.stdin:
        line = line.rstrip()
        if not in_exception and (line.startswith("Error") or line.startswith("Exception")):
            in_exception = True
            exception_lines.append(line)
            continue

        if in_exception:
            if line.startswith(' '):
                exception_lines.append(line)
            else:
                exception_ended()
                in_exception = False
    flush()


def print_exceptions():
    global exceptions, running_lock
    interval = float(options.interval)
    while True:
        time.sleep(interval)
        flush()


def flush():
    global exceptions, running_lock
    localExceptions = {}
    running_lock.acquire(True)
    try:
        localExceptions = exceptions
        exceptions = {}
    finally:
        running_lock.release()
    for exception, count in localExceptions.items():
        print(json.dumps({"ns": options.ns, "count": count, "exception": exception}))
    sys.stdout.flush()


thread = threading.Thread(target=print_exceptions)
thread.daemon = True
thread.start()

process_input()