Given http://tracker.ceph.com/issues/16673 or
    tracker.ceph.com/issues/16673, return "http://tracker.ceph.com".

def find_tracker_url(ticket_url):
    """
    Given http://tracker.ceph.com/issues/16673 or
    tracker.ceph.com/issues/16673, return "http://tracker.ceph.com".
    """
    if ticket_url.startswith('http://') or ticket_url.startswith('https://'):
        o = urlparse(ticket_url)
        scheme, netloc = o.scheme, o.netloc
    else:
        scheme = 'http'
        (netloc, _) = ticket_url.split('/', 1)
    return '%s://%s' % (scheme, netloc)