Uncaught exception on malformed url

[coagulant]

If http check is supplied with wrong url, say http:/example.com with one slash,
task fails with uncaught exception.

[2014-01-22 16:23:29,156: ERROR/MainProcess] Task app.cabotapp.tasks.run_status_check[190292be-0630-4781-9700-921ba6ae3ad0] raised unexpected: AttributeError("'NoneType' object has no attribute 'encode'",)
Traceback (most recent call last):
  File "/home/ubuntu/venv/local/lib/python2.7/site-packages/celery/app/trace.py", line 238, in trace_task
    R = retval = fun(*args, **kwargs)
  File "/home/ubuntu/venv/local/lib/python2.7/site-packages/celery/app/trace.py", line 416, in __protected_call__
    return self.run(*args, **kwargs)
  File "/home/ubuntu/2014-01-18-65148c3/app/cabotapp/tasks.py", line 42, in run_status_check
    check.run()
  File "/home/ubuntu/2014-01-18-65148c3/app/cabotapp/models.py", line 466, in run
    auth=auth
  File "/home/ubuntu/venv/local/lib/python2.7/site-packages/requests/api.py", line 65, in get
    return request('get', url, **kwargs)
  File "/home/ubuntu/venv/local/lib/python2.7/site-packages/requests/safe_mode.py", line 39, in wrapped
    return function(method, url, **kwargs)
  File "/home/ubuntu/venv/local/lib/python2.7/site-packages/requests/api.py", line 51, in request
    return session.request(method=method, url=url, **kwargs)
  File "/home/ubuntu/venv/local/lib/python2.7/site-packages/requests/sessions.py", line 241, in request
    r.send(prefetch=prefetch)
  File "/home/ubuntu/venv/local/lib/python2.7/site-packages/requests/models.py", line 629, in send
    timeout=self.timeout,
  File "/home/ubuntu/venv/local/lib/python2.7/site-packages/requests/packages/urllib3/connectionpool.py", line 415, in urlopen
    body=body, headers=headers)
  File "/home/ubuntu/venv/local/lib/python2.7/site-packages/requests/packages/urllib3/connectionpool.py", line 267, in _make_request
    conn.request(method, url, **httplib_request_kw)
  File "/usr/lib/python2.7/httplib.py", line 958, in request
    self._send_request(method, url, body, headers)
  File "/usr/lib/python2.7/httplib.py", line 986, in _send_request
    self.putrequest(method, url, **skips)
  File "/usr/lib/python2.7/httplib.py", line 896, in putrequest
    host_enc = self.host.encode("ascii")
AttributeError: 'NoneType' object has no attribute 'encode'

[dbuxton]

Well I guess there are two options: either make sure we validate the URL properly in the first place (we'll have to do manually as currently we're using a TextField for the URL) or just catch this exception and show as a failed check with some appropriate logging of the error. I'm probably in favour of the latter as we should be catching exceptions anyway.