OpenStack Keystone python client, Failed to contact the endpoint at "example:5000" for discovery

Question

I'm new to OpenStack clients and APIs

Today I was trying to connect to Keystone, And create a Client object like this:

from keystoneauth1.identity import v3
from keystoneclient.exceptions import ClientException
from keystoneauth1.session import Session
from keystoneclient.v3.client import Client

def keystone_client(version=(3, ), auth_url=None, user_id=None, password=None, project_id=None):
    auth = v3.Password(auth_url=auth_url,
                       user_id=user_id,
                       password=password,
                       project_id=project_id)
    sess = Session(auth=auth)
    try:
        return Client(session=sess)

    except ClientException as e:
        print(e)   # TODO: USE LOGGING

When I try to use the client with admin user credentials, and fetch users list, project list, any of keystone functionality like :

client = keystone_client(...)
clinet.services.list()
client.users.list()

First, this line in the client source code in a try-except block encounters exception and logs the bellow warning message

   LOG.warning('Failed to contact the endpoint at %s for discovery. Fallback '
                'to using that endpoint as the base url.', url)

Then finally throws a bunch of time out exceptions, traceback:

Failed to contact the endpoint at https://example:5000 for discovery. Fallback to using that endpoint as the base url.
Traceback (most recent call last):
  File "/home/arthur/codes/dir/test/venv/lib/python3.8/site-packages/urllib3/connection.py", line 159, in _new_conn
    conn = connection.create_connection(
  File "/home/arthur/codes/dir/test/venv/lib/python3.8/site-packages/urllib3/util/connection.py", line 84, in create_connection
    raise err
  File "/home/arthur/codes/dir/test/venv/lib/python3.8/site-packages/urllib3/util/connection.py", line 74, in create_connection
    sock.connect(sa)
TimeoutError: [Errno 110] Connection timed out

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/arthur/codes/dir/test/venv/lib/python3.8/site-packages/urllib3/connectionpool.py", line 670, in urlopen
    httplib_response = self._make_request(
  File "/home/arthur/codes/dir/test/venv/lib/python3.8/site-packages/urllib3/connectionpool.py", line 392, in _make_request
    conn.request(method, url, **httplib_request_kw)
  File "/usr/lib/python3.8/http/client.py", line 1255, in request
    self._send_request(method, url, body, headers, encode_chunked)
  File "/usr/lib/python3.8/http/client.py", line 1301, in _send_request
    self.endheaders(body, encode_chunked=encode_chunked)
  File "/usr/lib/python3.8/http/client.py", line 1250, in endheaders
    self._send_output(message_body, encode_chunked=encode_chunked)
  File "/usr/lib/python3.8/http/client.py", line 1010, in _send_output
    self.send(msg)
  File "/usr/lib/python3.8/http/client.py", line 950, in send
    self.connect()
  File "/home/arthur/codes/dir/test/venv/lib/python3.8/site-packages/urllib3/connection.py", line 187, in connect
    conn = self._new_conn()
  File "/home/arthur/codes/dir/test/venv/lib/python3.8/site-packages/urllib3/connection.py", line 171, in _new_conn
    raise NewConnectionError(
urllib3.exceptions.NewConnectionError: <urllib3.connection.HTTPConnection object at 0x7ffa929afb80>: Failed to establish a new connection: [Errno 110] Connection timed out

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/arthur/codes/dir/test/venv/lib/python3.8/site-packages/requests/adapters.py", line 439, in send
    resp = conn.urlopen(
  File "/home/arthur/codes/dir/test/venv/lib/python3.8/site-packages/urllib3/connectionpool.py", line 726, in urlopen
    retries = retries.increment(
  File "/home/arthur/codes/dir/test/venv/lib/python3.8/site-packages/urllib3/util/retry.py", line 446, in increment
    raise MaxRetryError(_pool, url, error or ResponseError(cause))
urllib3.exceptions.MaxRetryError: HTTPConnectionPool(host='example', port=5000): Max retries exceeded with url: /users (Caused by NewConnectionError('<urllib3.connection.HTTPConnection object at 0x7ffa929afb80>: Failed to establish a new connection: [Errno 110] Connection timed out'))

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/arthur/codes/dir/test/venv/lib/python3.8/site-packages/keystoneauth1/session.py", line 1012, in _send_request
    resp = self.session.request(method, url, **kwargs)
  File "/home/arthur/codes/dir/test/venv/lib/python3.8/site-packages/requests/sessions.py", line 530, in request
    resp = self.send(prep, **send_kwargs)
  File "/home/arthur/codes/dir/test/venv/lib/python3.8/site-packages/requests/sessions.py", line 643, in send
    r = adapter.send(request, **kwargs)
  File "/home/arthur/codes/dir/test/venv/lib/python3.8/site-packages/requests/adapters.py", line 516, in send
    raise ConnectionError(e, request=request)
requests.exceptions.ConnectionError: HTTPConnectionPool(host='example', port=5000): Max retries exceeded with url: /users (Caused by NewConnectionError('<urllib3.connection.HTTPConnection object at 0x7ffa929afb80>: Failed to establish a new connection: [Errno 110] Connection timed out'))

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "<console>", line 1, in <module>
  File "/home/arthur/codes/dir/test/venv/lib/python3.8/site-packages/debtcollector/renames.py", line 43, in decorator
    return wrapped(*args, **kwargs)
  File "/home/arthur/codes/dir/test/venv/lib/python3.8/site-packages/keystoneclient/v3/users.py", line 132, in list
    return super(UserManager, self).list(
  File "/home/arthur/codes/dir/test/venv/lib/python3.8/site-packages/keystoneclient/base.py", line 86, in func
    return f(*args, **new_kwargs)
  File "/home/arthur/codes/dir/test/venv/lib/python3.8/site-packages/keystoneclient/base.py", line 448, in list
    list_resp = self._list(url_query, self.collection_key)
  File "/home/arthur/codes/dir/test/venv/lib/python3.8/site-packages/keystoneclient/base.py", line 141, in _list
    resp, body = self.client.get(url, **kwargs)
  File "/home/arthur/codes/dir/test/venv/lib/python3.8/site-packages/keystoneauth1/adapter.py", line 395, in get
    return self.request(url, 'GET', **kwargs)
  File "/home/arthur/codes/dir/test/venv/lib/python3.8/site-packages/keystoneauth1/adapter.py", line 554, in request
    resp = super(LegacyJsonAdapter, self).request(*args, **kwargs)
  File "/home/arthur/codes/dir/test/venv/lib/python3.8/site-packages/keystoneauth1/adapter.py", line 257, in request
    return self.session.request(url, method, **kwargs)
  File "/home/arthur/codes/dir/test/venv/lib/python3.8/site-packages/keystoneauth1/session.py", line 921, in request
    resp = send(**kwargs)
  File "/home/arthur/codes/dir/test/venv/lib/python3.8/site-packages/keystoneauth1/session.py", line 1028, in _send_request
    raise exceptions.ConnectFailure(msg)
keystoneauth1.exceptions.connection.ConnectFailure: Unable to establish connection to http://example:5000/users?: HTTPConnectionPool(host='example', port=5000): Max retries exceeded with url: /users (Caused by NewConnectionError('<urllib3.connection.HTTPConnection object at 0x7ffa929afb80>: Failed to establish a new connection: [Errno 110] Connection timed out'))

All of the functions including that user listing works fine in both Keystone Identity raw API and the OpenStack command-line client. It seems that the python-keystone-client looks into the service catalog and figure out which end-point it should use, but finally, that endpoint it decides to use is an internal endpoint, and not supposed to be used directly.

Anyone else had this problem?

Answer 1

There is an argument named 'interface' which gets 'public', 'internal' and 'admin' as its value. Which in order to prevent Keystone client to try private endpoints, it should be passed like this:

client = Client(session, interface='public')