I get a hook error from the grafana charm when trying to create a relation from an operator charm.
nit-grafana-4: 18:04:03 ERROR unit.grafana/4.juju-log grafana-source:233: Hook error:
Traceback (most recent call last):
File "/var/lib/juju/agents/unit-grafana-4/.venv/lib/python3.6/site-packages/charms/reactive/__init__.py", line 74, in main
bus.dispatch(restricted=restricted_mode)
File "/var/lib/juju/agents/unit-grafana-4/.venv/lib/python3.6/site-packages/charms/reactive/bus.py", line 379, in dispatch
_invoke(hook_handlers)
File "/var/lib/juju/agents/unit-grafana-4/.venv/lib/python3.6/site-packages/charms/reactive/bus.py", line 359, in _invoke
handler.invoke()
File "/var/lib/juju/agents/unit-grafana-4/.venv/lib/python3.6/site-packages/charms/reactive/bus.py", line 181, in invoke
self._action(*args)
File "/var/lib/juju/agents/unit-grafana-4/charm/hooks/relations/grafana-source/requires.py", line 11, in changed
conv = self.conversation()
File "/var/lib/juju/agents/unit-grafana-4/.venv/lib/python3.6/site-packages/charms/reactive/relations.py", line 431, in conversation
raise ValueError('Unable to determine default scope: no current hook or global scope')
ValueError: Unable to determine default scope: no current hook or global scope
The grafana charm (a reactive charm) defines the requiring side of the grafana-source relation, while my charm (an operator charm) defines the provides side.
for conv in self.conversations():
ds = {'service_name': conv.scope.split('/')[0],
I think there is an issue somewhere in that the relating charm is not using the reactive framework and won’t have a conversation or conversation scope. I think there may be an issue with the reactive/conversation expecting the scope to be there when it isn’t available via the operator charm side of the relation.
Possibly I have this all mixed up and its something entirely different.
I’m wondering if there is a way to set the scope from an operator charm interface in a way that will be compatible with what reactive charms and/or what conversations expect to be available?
The scope for old (pre-Endpoint) style reactive interface layers should be handled entirely on the local charm side, so it shouldn’t matter what you’re relating it to. Specifically, the scope value for that interface (which is scopes.SERVICE) should be translated to the remote application name.
Since that traceback says it’s in the changed handler, which should only be called during a relation hook, I would definitely expect for JUJU_REMOTE_UNIT to be set. The only thing I can think of is that at some other point, hookenv.remote_service_name() was called without a relation ID outside of a relation hook and cached a None value. TBH, I don’t think that function should be cached at all, but either way, a better fix would be refactoring that interface layer to use Endpoint instead.
I would tend to agree with @cory_fu that this is likely a bug on the grafana charm side related to that cached remote_service_name function. Everything else about the code looks as if it’s executing in the proper relation context.
I’d like to get a bug filed against lp:interface-grafana-source related to the deprecated status of RelationBase and scopes. To that end, @jamesbeedy, would you be able to provide more context around that Traceback log you’ve provided and, if public, a link to your operator charm provides code and related bits of your deployed bundle for reproduction purposes?
git clone https://github.com/omnivector-solutions/rev2 -b bdx_next && cd rev2
make charms
juju deploy ./bundles/slurm-core-focal-aws-influxdb-grafana/bundle-no-spaces.yaml
no
The result, after deploying the bundle, should look like:
Model Controller Cloud/Region Version SLA Timestamp
bdx-rats osl-aws aws/us-west-2 2.8.1 unsupported 02:56:05Z
App Version Status Scale Charm Store Rev OS Notes
grafana error 1 grafana jujucharms 37 ubuntu
influxdb active 1 influxdb jujucharms 23 ubuntu
percona-cluster 5.7.20 active 1 percona-cluster jujucharms 291 ubuntu
slurm-configurator active 1 slurm-configurator local 54 ubuntu
slurmctld 20.02.1 active 1 slurmctld local 41 ubuntu
slurmd 20.02.1 active 1 slurmd local 23 ubuntu
slurmdbd 20.02.1 active 1 slurmdbd local 30 ubuntu
Unit Workload Agent Machine Public address Ports Message
grafana/5* error idle 168 172.31.82.15 3000/tcp hook failed: "grafana-source-relation-changed"
influxdb/5* active idle 169 172.31.80.152 8083/tcp,8086/tcp
percona-cluster/16* active idle 170 172.31.81.42 3306/tcp Unit is ready
slurm-configurator/34* active idle 171 172.31.82.254
slurmctld/32* active idle 172 172.31.83.216 Slurmctld Available
slurmd/24* active idle 173 172.31.80.234 Slurmd Available
slurmdbd/32* active idle 174 172.31.81.174 Slurmdbd Available
Machine State DNS Inst id Series AZ Message
168 started 172.31.82.15 i-0cca521d3976d562b focal us-west-2c running
169 started 172.31.80.152 i-0edb6b7b89a041821 focal us-west-2a running
170 started 172.31.81.42 i-012b7d4eea1f9385b bionic us-west-2b running
171 started 172.31.82.254 i-075a6707fb3f50068 focal us-west-2c running
172 started 172.31.83.216 i-0a5d9a1f510569570 focal us-west-2d running
173 started 172.31.80.234 i-0923d1c53a9611b93 focal us-west-2a running
174 started 172.31.81.174 i-0af7db23bea934c11 focal us-west-2b running
The grafana unit errors with:
juju debug-log --include grafana
unit-grafana-5: 02:56:34 ERROR unit.grafana/5.juju-log grafana-source:239: Hook error:
Traceback (most recent call last):
File "/var/lib/juju/agents/unit-grafana-5/.venv/lib/python3.8/site-packages/charms/reactive/__init__.py", line 74, in main
bus.dispatch(restricted=restricted_mode)
File "/var/lib/juju/agents/unit-grafana-5/.venv/lib/python3.8/site-packages/charms/reactive/bus.py", line 379, in dispatch
_invoke(hook_handlers)
File "/var/lib/juju/agents/unit-grafana-5/.venv/lib/python3.8/site-packages/charms/reactive/bus.py", line 359, in _invoke
handler.invoke()
File "/var/lib/juju/agents/unit-grafana-5/.venv/lib/python3.8/site-packages/charms/reactive/bus.py", line 181, in invoke
self._action(*args)
File "/var/lib/juju/agents/unit-grafana-5/charm/hooks/relations/grafana-source/requires.py", line 11, in changed
conv = self.conversation()
File "/var/lib/juju/agents/unit-grafana-5/.venv/lib/python3.8/site-packages/charms/reactive/relations.py", line 431, in conversation
raise ValueError('Unable to determine default scope: no current hook or global scope')
ValueError: Unable to determine default scope: no current hook or global scope
@afreiberger I made a pr against each of interface-grafana-source and charm-grafana that fix the issue for me. If you want to implement it differently, feel free to discard my changes. I thought I would propose them none the less.
