#!/usr/bin/env python

import socket
import re
import sys


def check_webserver(address, port, resource):
    #build up HTTP request string
    if not resource.startswith('/'):
        resource = '/' + resource
    request_string = "GET %s HTTP/1.1\r\nHost: %s\r\n\r\n" % (resource, address)
    print 'HTTP request:'
    print '|||%s|||' % request_string

    #create a TCP socket
    s = socket.socket()
    print "Attempting to connect to %s on port %s" % (address, port)
    try:
        s.connect((address, port))
        print "Connected to %s on port %s" % (address, port)
        s.send(request_string)
        #we should only need the first 100 bytes or so
        rsp = s.recv(100)
        print 'Received 100 bytes of HTTP response'
        print '|||%s|||' % rsp
    except socket.error, e:
        print "Connection to %s on port %s failed: %s" % (address, port, e)
        return False
    finally:
        #be a good citizen and close your connection
        print "Closing the connection"
        s.close()
    lines = rsp.splitlines()
    print 'First line of HTTP response: %s' % lines[0]
    try:
        version, status, message = re.split(r'\s+', lines[0], 2)
        print 'Version: %s, Status: %s, Message: %s' % (version, status, message)
    except ValueError:
        print 'Failed to split status line'
        return False
    if status in ['200', '301']:
        print 'Success - status was %s' % status
        return True
    else:
        print 'Status was %s' % status
        return False

if __name__ == '__main__':
    from optparse import OptionParser
    parser = OptionParser()
    parser.add_option("-a", "--address", dest="address", default='localhost',
                      help="ADDRESS for webserver", metavar="ADDRESS")

    parser.add_option("-p", "--port", dest="port", type="int", default=80,
                      help="PORT for webserver", metavar="PORT")

    parser.add_option("-r", "--resource", dest="resource", default='index.html',
                      help="RESOURCE to check", metavar="RESOURCE")

    (options, args) = parser.parse_args()
    print 'options: %s, args: %s' % (options, args)
    check = check_webserver(options.address, options.port, options.resource)
    print 'check_webserver returned %s' % check
    sys.exit(not check)