Adding nrpe relation fails for nrpe-external-master-relation-{joined, changed}

[Diko Parvanov]

Revision 47, affects focal and bionic.

unit-ntp-15: 09:28:42 ERROR unit.ntp/15.juju-log nrpe-external-master:22788: Hook error:
Traceback (most recent call last):
  File "/var/lib/juju/agents/unit-ntp-15/.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-ntp-15/.venv/lib/python3.6/site-packages/charms/reactive/bus.py", line 379, in dispatch
    _invoke(hook_handlers)
  File "/var/lib/juju/agents/unit-ntp-15/.venv/lib/python3.6/site-packages/charms/reactive/bus.py", line 359, in _invoke
    handler.invoke()
  File "/var/lib/juju/agents/unit-ntp-15/.venv/lib/python3.6/site-packages/charms/reactive/bus.py", line 181, in invoke
    self._action(*args)
  File "/var/lib/juju/agents/unit-ntp-15/charm/hooks/relations/nrpe-external-master/provides.py", line 16, in changed_nrpe
    self.set_state('{relation_name}.available')
  File "/var/lib/juju/agents/unit-ntp-15/.venv/lib/python3.6/site-packages/charms/reactive/relations.py", line 476, in set_state
    self.conversation(scope).set_state(state)
  File "/var/lib/juju/agents/unit-ntp-15/.venv/lib/python3.6/site-packages/charms/reactive/relations.py", line 716, in set_state
    if self.key not in value['conversations']:
TypeError: 'NoneType' object is not subscriptable

Workaround for this is to go into debug-hooks for the unit and run

charms.reactive set_state nrpe-external-master.available

for each hook execution that fails (joined, then changed)

[Paul Goins (vultaire)]

Also observed with cs:ntp-45.

[Graeme Moss (graememoss)]

Have the same problem with ntp rev 47 from charmhub
unit-ntp-10: 09:42:16 WARNING unit.ntp/10.nrpe-external-master-relation-joined File "/var/lib/juju/agents/unit-ntp-10/.venv/lib/python3.6/site-packages/charms/reactive/relations.py", line 716, in set_state
unit-ntp-10: 09:42:16 WARNING unit.ntp/10.nrpe-external-master-relation-joined if self.key not in value['conversations']:
unit-ntp-10: 09:42:16 WARNING unit.ntp/10.nrpe-external-master-relation-joined TypeError: 'NoneType' object is not subscriptable
unit-ntp-10: 09:42:16 ERROR juju.worker.uniter.operation hook "nrpe-external-master-relation-joined" (via explicit, bespoke hook script) failed: exit status 1
unit-ntp-10: 09:42:16 INFO juju.worker.uniter awaiting error resolution for "relation-joined" hook

tried using debug-hook I get the following:

bash: warning: setlocale: LC_ALL: cannot change locale (en_GB.UTF-8)
root@cz21260l6h:~# charms.reactive set_state nrpe-external-master.available
/bin/bash: warning: setlocale: LC_ALL: cannot change locale (en_GB.UTF-8)
Ambiguous possibilities for JUJU_CHARM_DIR; please use --charm or run within a Juju hook context
root@cz21260l6h:~#

The debug-hooks does not go into a session to run the charm.reactive commands.

[Graeme Moss (graememoss)]

2022-04-12 09:59:37 INFO juju.worker.uniter resolver.go:150 awaiting error resolution for "relation-joined" hook
2022-04-12 09:59:42 INFO juju.worker.uniter resolver.go:150 awaiting error resolution for "relation-joined" hook
2022-04-12 09:59:50 INFO juju.worker.uniter.runner runner.go:465 executing nrpe-external-master-relation-joined via debug-hooks; explicit, bespoke hook script

Still nothing on the debug-hook
bash: warning: setlocale: LC_ALL: cannot change locale (en_GB.UTF-8)
bash: warning: setlocale: LC_ALL: cannot change locale (en_GB.UTF-8)
root@cz21260l6h:~#