Manager crash when launch in k8s

connected to master
Traceback (most recent call last):
File "/usr/local/lib/python3.6/site-packages/urllib3/connectionpool.py", line 601, in urlopen
chunked=chunked)
File "/usr/local/lib/python3.6/site-packages/urllib3/connectionpool.py", line 357, in _make_request
conn.request(method, url, **httplib_request_kw)
File "/usr/local/lib/python3.6/http/client.py", line 1239, in request
self._send_request(method, url, body, headers, encode_chunked)
File "/usr/local/lib/python3.6/http/client.py", line 1285, in _send_request
self.endheaders(body, encode_chunked=encode_chunked)
File "/usr/local/lib/python3.6/http/client.py", line 1234, in endheaders
self._send_output(message_body, encode_chunked=encode_chunked)
File "/usr/local/lib/python3.6/http/client.py", line 1026, in _send_output
self.send(msg)
File "/usr/local/lib/python3.6/http/client.py", line 964, in send
self.connect()
File "/usr/local/lib/python3.6/site-packages/docker/transport/unixconn.py", line 33, in connect
sock.connect(self.unix_socket)
ConnectionRefusedError: [Errno 111] Connection refused
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "/usr/local/lib/python3.6/site-packages/requests/adapters.py", line 440, in send
timeout=timeout
File "/usr/local/lib/python3.6/site-packages/urllib3/connectionpool.py", line 639, in urlopen
_stacktrace=sys.exc_info()[2])
File "/usr/local/lib/python3.6/site-packages/urllib3/util/retry.py", line 357, in increment
raise six.reraise(type(error), error, _stacktrace)
File "/usr/local/lib/python3.6/site-packages/urllib3/packages/six.py", line 685, in reraise
raise value.with_traceback(tb)
File "/usr/local/lib/python3.6/site-packages/urllib3/connectionpool.py", line 601, in urlopen
chunked=chunked)
File "/usr/local/lib/python3.6/site-packages/urllib3/connectionpool.py", line 357, in _make_request
conn.request(method, url, **httplib_request_kw)
File "/usr/local/lib/python3.6/http/client.py", line 1239, in request
self._send_request(method, url, body, headers, encode_chunked)
File "/usr/local/lib/python3.6/http/client.py", line 1285, in _send_request
self.endheaders(body, encode_chunked=encode_chunked)
File "/usr/local/lib/python3.6/http/client.py", line 1234, in endheaders
self._send_output(message_body, encode_chunked=encode_chunked)
File "/usr/local/lib/python3.6/http/client.py", line 1026, in _send_output
self.send(msg)
File "/usr/local/lib/python3.6/http/client.py", line 964, in send
self.connect()
File "/usr/local/lib/python3.6/site-packages/docker/transport/unixconn.py", line 33, in connect
sock.connect(self.unix_socket)
urllib3.exceptions.ProtocolError: ('Connection aborted.', ConnectionRefusedError(111, 'Connection refused'))
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "./manager.py", line 97, in
main()
File "./manager.py", line 93, in main
docker_checker()
File "./manager.py", line 64, in docker_checker
this_container = client.containers.get(my_hostname)
File "/usr/local/lib/python3.6/site-packages/docker/models/containers.py", line 778, in get
resp = self.client.api.inspect_container(container_id)
File "/usr/local/lib/python3.6/site-packages/docker/utils/decorators.py", line 19, in wrapped
return f(self, resource_id, *args, **kwargs)
File "/usr/local/lib/python3.6/site-packages/docker/api/container.py", line 756, in inspect_container
self._get(self._url("/containers/{0}/json", container)), True
File "/usr/local/lib/python3.6/site-packages/docker/utils/decorators.py", line 46, in inner
return f(self, *args, **kwargs)
File "/usr/local/lib/python3.6/site-packages/docker/api/client.py", line 189, in _get
return self.get(url, **self._set_request_timeout(kwargs))
File "/usr/local/lib/python3.6/site-packages/requests/sessions.py", line 521, in get
return self.request('GET', url, **kwargs)
File "/usr/local/lib/python3.6/site-packages/requests/sessions.py", line 508, in request
resp = self.send(prep, **send_kwargs)
File "/usr/local/lib/python3.6/site-packages/requests/sessions.py", line 618, in send
r = adapter.send(request, **kwargs)
File "/usr/local/lib/python3.6/site-packages/requests/adapters.py", line 490, in send
raise ConnectionError(err, request=request)
requests.exceptions.ConnectionError: ('Connection aborted.', ConnectionRefusedError(111, 'Connection refused'))

Read manager.py at docker_checker() on line 64 and main() on line 93, then reproduce the manager launch in Kubernetes while checking why the Docker client connection is refused. Done means the manager no longer crashes in this launch scenario and the relevant launch or test procedure confirms the fix.

Written by the indexing model from the issue text.