What do I do if the Cinder client returns 'ERROR: Unable to establish connection' message and fails to connect?

Versions of python-cinderclient from 1.2.0 up and prior to 1.3.0 may give an error and fail when attempting to connect to a Cinder API service that is configured to use the HTTPS protocol.

For example:

$ cinder list
ERROR: Unable to establish connection to http://<cinderURL>:<cinderPort>/v1/<tenantID>/volumes/detail

This situation appears to be related to version discovery support that was added in version 1.2.0 and reverted in 1.3.0. (See the release notes for more details: http://docs.openstack.org/developer/python-cinderclient/).

If you experience this issue, upgrade the python-cinderclient package to 1.3.0 or later by running

pip install -U python-cinderclient

or by upgrading the package that provides the client if using an OpenStack distribution.

For example:

yum update python-cinderclient