root@c1:/opt/openstack-ansible/playbooks# openstack-ansible setup-infrastructure.yml
Variable files: "-e @/etc/openstack_deploy/user_secrets.yml -e @/etc/openstack_deploy/user_variables.yml "

PLAY [Install memcached] ******************************************************

GATHERING FACTS ***************************************************************
fatal: [c1_memcached_container-77ddfa18] => Traceback (most recent call last):
  File "/usr/local/lib/python2.7/dist-packages/ansible/runner/__init__.py", line 586, in _executor
    exec_rc = self._executor_internal(host, new_stdin)
  File "/usr/local/lib/python2.7/dist-packages/ansible/runner/__init__.py", line 789, in _executor_internal
    return self._executor_internal_inner(host, self.module_name, self.module_args, inject, port, complex_args=complex_args)
  File "/usr/local/lib/python2.7/dist-packages/ansible/runner/__init__.py", line 968, in _executor_internal_inner
    conn = self.connector.connect(actual_host, actual_port, actual_user, actual_pass, actual_transport, actual_private_key_file, delegate_host)
  File "/usr/local/lib/python2.7/dist-packages/ansible/runner/connection.py", line 35, in connect
    conn = utils.plugins.connection_loader.get(transport, self.runner, host, port, user=user, password=password, private_key_file=private_key_file)
  File "/usr/local/lib/python2.7/dist-packages/ansible/utils/plugins.py", line 219, in get
    return getattr(self._module_cache[path], self.class_name)(*args, **kwargs)
  File "/usr/local/lib/python2.7/dist-packages/ansible/runner/connection_plugins/ssh.py", line 44, in __init__
    self.ipv6 = ':' in self.host
TypeError: argument of type 'NoneType' is not iterable

fatal: [c2_memcached_container-0cbf265c] => Traceback (most recent call last):
  File "/usr/local/lib/python2.7/dist-packages/ansible/runner/__init__.py", line 586, in _executor
    exec_rc = self._executor_internal(host, new_stdin)
  File "/usr/local/lib/python2.7/dist-packages/ansible/runner/__init__.py", line 789, in _executor_internal
    return self._executor_internal_inner(host, self.module_name, self.module_args, inject, port, complex_args=complex_args)
  File "/usr/local/lib/python2.7/dist-packages/ansible/runner/__init__.py", line 968, in _executor_internal_inner
    conn = self.connector.connect(actual_host, actual_port, actual_user, actual_pass, actual_transport, actual_private_key_file, delegate_host)
  File "/usr/local/lib/python2.7/dist-packages/ansible/runner/connection.py", line 35, in connect
    conn = utils.plugins.connection_loader.get(transport, self.runner, host, port, user=user, password=password, private_key_file=private_key_file)
  File "/usr/local/lib/python2.7/dist-packages/ansible/utils/plugins.py", line 219, in get
    return getattr(self._module_cache[path], self.class_name)(*args, **kwargs)
  File "/usr/local/lib/python2.7/dist-packages/ansible/runner/connection_plugins/ssh.py", line 44, in __init__
    self.ipv6 = ':' in self.host
TypeError: argument of type 'NoneType' is not iterable

fatal: [c3_memcached_container-61f04e24] => Traceback (most recent call last):
  File "/usr/local/lib/python2.7/dist-packages/ansible/runner/__init__.py", line 586, in _executor
    exec_rc = self._executor_internal(host, new_stdin)
  File "/usr/local/lib/python2.7/dist-packages/ansible/runner/__init__.py", line 789, in _executor_internal
    return self._executor_internal_inner(host, self.module_name, self.module_args, inject, port, complex_args=complex_args)
  File "/usr/local/lib/python2.7/dist-packages/ansible/runner/__init__.py", line 968, in _executor_internal_inner
    conn = self.connector.connect(actual_host, actual_port, actual_user, actual_pass, actual_transport, actual_private_key_file, delegate_host)
  File "/usr/local/lib/python2.7/dist-packages/ansible/runner/connection.py", line 35, in connect
    conn = utils.plugins.connection_loader.get(transport, self.runner, host, port, user=user, password=password, private_key_file=private_key_file)
  File "/usr/local/lib/python2.7/dist-packages/ansible/utils/plugins.py", line 219, in get
    return getattr(self._module_cache[path], self.class_name)(*args, **kwargs)
  File "/usr/local/lib/python2.7/dist-packages/ansible/runner/connection_plugins/ssh.py", line 44, in __init__
    self.ipv6 = ':' in self.host
TypeError: argument of type 'NoneType' is not iterable