Intermittent connection issue

get-ip-output

# Successful request output

trellis@debian:~/rackspace-cloud-env$ python get-ip.py                                                                                                           
INFO:requests.packages.urllib3.connectionpool:Starting new HTTPS connection (1): lon.servers.api.rackspacecloud.com
DEBUG:requests.packages.urllib3.connectionpool:"GET /v2/xxxxx/servers/detail HTTP/1.1" 200 1643
Name: xxxx
 ID: xxxx
 Public IP: 1.2.3.4

# Unsuccessful request output

trellis@debian:~/rackspace-cloud-env$ python get-ip.py 
INFO:requests.packages.urllib3.connectionpool:Starting new HTTPS connection (1): lon.lon.servers.api.rackspacecloud.com
Traceback (most recent call last):
  File "get-ip.py", line 46, in <module>
    get_public_addr()
  File "get-ip.py", line 22, in get_public_addr
    servers = cs.servers.list()
  File "/home/trellis/rackspace-cloud-env/local/lib/python2.7/site-packages/novaclient/v1_1/servers.py", line 375, in list
    return self._list("/servers%s%s" % (detail, query_string), "servers")
  File "/home/trellis/rackspace-cloud-env/local/lib/python2.7/site-packages/novaclient/base.py", line 62, in _list
    _resp, body = self.api.client.get(url)
  File "/home/trellis/rackspace-cloud-env/local/lib/python2.7/site-packages/novaclient/client.py", line 230, in get
    return self._cs_request(url, 'GET', **kwargs)
  File "/home/trellis/rackspace-cloud-env/local/lib/python2.7/site-packages/novaclient/client.py", line 217, in _cs_request
    **kwargs)
  File "/home/trellis/rackspace-cloud-env/local/lib/python2.7/site-packages/novaclient/client.py", line 199, in _time_request
    resp, body = self.request(url, method, **kwargs)
  File "/home/trellis/rackspace-cloud-env/local/lib/python2.7/site-packages/novaclient/client.py", line 170, in request
    **kwargs)
  File "/home/trellis/rackspace-cloud-env/local/lib/python2.7/site-packages/requests/api.py", line 44, in request
    return session.request(method=method, url=url, **kwargs)
  File "/home/trellis/rackspace-cloud-env/local/lib/python2.7/site-packages/requests/sessions.py", line 354, in request
    resp = self.send(prep, **send_kwargs)
  File "/home/trellis/rackspace-cloud-env/local/lib/python2.7/site-packages/requests/sessions.py", line 460, in send
    r = adapter.send(request, **kwargs)
  File "/home/trellis/rackspace-cloud-env/local/lib/python2.7/site-packages/requests/adapters.py", line 246, in send
    raise ConnectionError(e)
requests.exceptions.ConnectionError: HTTPSConnectionPool(host='lon.lon.servers.api.rackspacecloud.com', port=443): Max retries exceeded with url: /v2/xxxxx/servers/detail (Caused by <class 'socket.gaierror'>: [Errno -2] Name or service not known)