A simple website monitor

.gitignore

*.pyc

README.md

A simple website monitor.

1. Edit config.py and add a list of URLs.
2. Set up a cron job to run python monitor.py periodically

config.py

sender = 'monitor@gramener.com'
to = 's.anand@gramener.com'
subject = 'Site monitoring errors'
sendmail = '/usr/sbin/sendmail'

urls = (
    'http://gramener.com/',
    'http://blog.gramener.com/',
)

monitor.py

#!/usr/bin/python

"""
A simple website HTTP header monitor tool.
"""

import re
import urllib2


def monitor_url(url, tests):
    response = urllib2.urlopen(url)
    info = response.info()
    info['Status'] = str(response.getcode())
    for header, pattern in tests:
        value = info.getheader(header)
        if not re.match(pattern, value):
            raise AssertionError(
                '%s: %s does not match %s' %
                (header, value, pattern))

if __name__ == '__main__':
    import config
    from os.path import exists
    from email.mime.text import MIMEText
    from subprocess import Popen, PIPE

    messages = []
    for row in config.urls:
        try:
            if isinstance(row, basestring):
                url = row
                monitor_url(url, [])
            elif hasattr(row, '__getitem__') and hasattr(row, '__len__'):
                if len(row) > 1:
                    url, tests = row[0], row[1]
                    monitor_url(url, tests)
        except urllib2.URLError, e:
            # Ignore these messages
            pass
        except Exception, e:
            messages.append([url, str(e)])

    if len(messages) > 0:
        msg = '\n\n'.join(
            url + '\n' + msg
            for url, msg in messages
        )
        if exists(config.sendmail):
            msg = MIMEText(msg)
            msg['From'] = config.sender
            msg['To'] = config.to
            msg['Subject'] = config.subject + ' %d/%d' % (
                len(messages), len(config.urls))
            p = Popen([config.sendmail, '-t'], stdin=PIPE)
            p.communicate(msg.as_string())
        else:
            print msg