client-relation-joined fails when relating ceph-proxy to gnocchi or nova-compute

[Przemyslaw Hausman]

Relating gnocchi (or nova-compute) with ceph-proxy ends up with ceph-proxy in error state due to failed client-relation-joined:

unit-ceph-proxy-0: 23:24:56 WARNING unit.ceph-proxy/0.juju-log client:354: Support for use of upstream ``apt_pkg`` module in conjunctionwith charm-helpers is deprecated since 2019-06-25
unit-ceph-proxy-0: 23:24:56 DEBUG unit.ceph-proxy/0.client-relation-joined exported keyring for client.gnocchi
unit-ceph-proxy-0: 23:24:56 WARNING unit.ceph-proxy/0.juju-log client:354: Support for use of upstream ``apt_pkg`` module in conjunctionwith charm-helpers is deprecated since 2019-06-25
unit-ceph-proxy-0: 23:24:57 DEBUG unit.ceph-proxy/0.juju-log client:354: Processing request 28605292-4aca-11ea-9c17-00163e4e5dd8
unit-ceph-proxy-0: 23:24:57 INFO unit.ceph-proxy/0.juju-log client:354: Processing 1 ceph broker requests
unit-ceph-proxy-0: 23:24:57 DEBUG unit.ceph-proxy/0.juju-log client:354: Processing op='create-pool'
unit-ceph-proxy-0: 23:24:57 WARNING unit.ceph-proxy/0.juju-log client:354: Support for use of upstream ``apt_pkg`` module in conjunctionwith charm-helpers is deprecated since 2019-06-25
unit-ceph-proxy-0: 23:24:57 DEBUG unit.ceph-proxy/0.juju-log client:354: Pool 'gnocchi' already exists - skipping create
unit-ceph-proxy-0: 23:24:57 DEBUG unit.ceph-proxy/0.client-relation-joined Traceback (most recent call last):
unit-ceph-proxy-0: 23:24:57 DEBUG unit.ceph-proxy/0.client-relation-joined File "/var/lib/juju/agents/unit-ceph-proxy-0/charm/hooks/client-relation-joined", line 292, in <module>
unit-ceph-proxy-0: 23:24:57 DEBUG unit.ceph-proxy/0.client-relation-joined hooks.execute(sys.argv)
unit-ceph-proxy-0: 23:24:57 DEBUG unit.ceph-proxy/0.client-relation-joined File "/var/lib/juju/agents/unit-ceph-proxy-0/charm/charmhelpers/core/hookenv.py", line 914, in execute
unit-ceph-proxy-0: 23:24:57 DEBUG unit.ceph-proxy/0.client-relation-joined self._hooks[hook_name]()
unit-ceph-proxy-0: 23:24:57 DEBUG unit.ceph-proxy/0.client-relation-joined File "/var/lib/juju/agents/unit-ceph-proxy-0/charm/hooks/client-relation-joined", line 209, in client_relation_joined
unit-ceph-proxy-0: 23:24:57 DEBUG unit.ceph-proxy/0.client-relation-joined unit_id = unit.replace('/', '-')
unit-ceph-proxy-0: 23:24:57 DEBUG unit.ceph-proxy/0.client-relation-joined AttributeError: 'NoneType' object has no attribute 'replace'
unit-ceph-proxy-0: 23:24:57 ERROR juju.worker.uniter.operation hook "client-relation-joined" failed: exit status 1

DEPLOYMENT
bionic-stein

CHARM REVISIONS
ceph-proxy: Revision 26
gnocchi: Revision 32, Version 4.3.2

ADDITIONAL INFORMATION
I have added a few debug printouts in client-relation-joined code and gathered the data passed to the function.

relid: None
unit: None
units: ['gnocchi/2']
settings: {'broker_req': '{"api-version": 1, "ops": [{"op": "create-pool", "name": "gnocchi", "replicas": 3, "pg_num": null, "weight": null, "group": null, "group-namespace": null, "app-name": null, "max-bytes": null, "max-objects": null}], "request-id": "79847532-4ace-11ea-9c17-00163e4e5dd8"}', 'egress-subnets': '10.127.1.10/32', 'ingress-address': '10.127.1.10', 'private-address': '10.127.1.10'}

The code fails because 'settings' is not None and 'unit' is None.

When applied the following patch, the relation has been successfully executed:

diff --git a/ceph_hooks.py.orig b/ceph_hooks.py
index a637ff6..ab126d8 100755
--- a/ceph_hooks.py.orig
+++ b/ceph_hooks.py
@@ -206,7 +206,7 @@ def client_relation_joined(relid=None, unit=None):
             data_update = {}
             if 'broker_req' in settings:
                 rsp = process_requests(settings['broker_req'])
- unit_id = unit.replace('/', '-')
+ unit_id = units[0].replace('/', '-')
                 unit_response_key = 'broker-rsp-' + unit_id
                 data_update[unit_response_key] = rsp
             data.update(data_update)

[Pedro Guimarães (pguimaraes)]

Hi, we are seeing the same issue with ceph-proxy: https://pastebin.canonical.com/p/WTcf7s6Pw5/

[Chris MacNaughton (chris.macnaughton)]

A fix has been proposed at https://review.opendev.org/#/c/707353

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/707353
Committed: https://git.openstack.org/cgit/openstack/charm-ceph-proxy/commit/?id=649bdb4683578c7bd5bff235dd1e4551d3b91a45
Submitter: Zuul
Branch: master

commit 649bdb4683578c7bd5bff235dd1e4551d3b91a45
Author: Chris MacNaughton <email address hidden>
Date: Wed Feb 12 11:26:46 2020 +0100

    Ensure that we define `unit` before use

    When ceph-proxy is configured prior to being related
    to clients, it is possible for the units to go into
    a hook error because of an undefined variable. This
    change ensures that we do correctly define the unit
    before we use it.

    Change-Id: Ic6e28783bde4fc342d7c5ef1d733e69a03b702fe
    Closes-Bug: #1862487