[20.05] keystone-fid-service-provider-relation-joined failed: AttributeError: 'NoneType' object has no attribute 'strip'

[Dmitrii Shcherbakov]

charm-keystone tries to use .strip on a value returned for 'protocol-name' without checking if it is None or not first.

https://review.opendev.org/#/c/690597/13
https://openstack-ci-reports.ubuntu.com/artifacts/test_charm_pipeline_func_full/openstack/charm-keystone-saml-mellon/690597/13/5928/index.html
https://openstack-ci-reports.ubuntu.com/artifacts/test_charm_pipeline_func_full/openstack/charm-keystone-saml-mellon/690597/13/5928/test_charm_func_full_9069/juju-crashdump-27d1cfea-67a4-4f21-943e-e017cec479a1.tar.xz

2020-06-03 20:23:17 DEBUG keystone-fid-service-provider-relation-joined _ctxt = context()
2020-06-03 20:23:17 DEBUG keystone-fid-service-provider-relation-joined File "/var/lib/juju/agents/unit-keystone-1/charm/hooks/keystone_context.py", line 445, in __call__
2020-06-03 20:23:17 DEBUG keystone-fid-service-provider-relation-joined _protocol_name = rdata.get('protocol-name').strip('"')
2020-06-03 20:23:17 DEBUG keystone-fid-service-provider-relation-joined AttributeError: 'NoneType' object has no attribute 'strip'
2020-06-03 20:23:17 ERROR juju.worker.uniter.operation runhook.go:132 hook "keystone-fid-service-provider-relation-joined" failed: exit status 1

hooks/keystone_context.py:
                rdata = relation_get(unit=unit, rid=rid)
                _protocol_name = rdata.get('protocol-name').strip('"')
                if _protocol_name and _protocol_name not in self.auth_methods:
                    self.auth_methods.append(_protocol_name)
                    # We are federated so remove the external method
                    if _external in self.auth_methods:
                        self.auth_methods.remove(_external)

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/733635
Committed: https://git.openstack.org/cgit/openstack/charm-keystone/commit/?id=4eb640ab56a48f49f354fd4c4ae929c763e72f61
Submitter: Zuul
Branch: master

commit 4eb640ab56a48f49f354fd4c4ae929c763e72f61
Author: Dmitrii Shcherbakov <email address hidden>
Date: Thu Jun 4 17:46:36 2020 +0300

    Return an empty string if relation data is missing

    None is returned for a relation data value if a key isn't present -
    assuming that it's a string is not correct. This change fixes that by
    returning an empty string if protocol-name is not present.

    Change-Id: I2bab6a69f9f663edee0738ff35b804d81736cb5c
    Closes-Bug: #1882084