Running list-backups actions shortly after relation with s3-integrator results in IndexError

[shayancanonical]

Steps to reproduce

1. juju deploy postgresql --revision 526
2. juju deploy s3-integrator
3. juju run s3-integrator/0 sync-s3-credentials access-key=<access_key> secret-key=<secret_key>
4. juju config s3-integrator endpoint=<s3_endpoint> bucket=<s3_bucket> path= region=
5. as soon as relation formed, juju run postgresql/leader list-backups

Expected behavior

No exceptions throws, action completes successfully

Actual behavior

Error thrown

Versions

Operating system: Ubuntu 24.04

Juju CLI: 3.6.1-genericlinux-amd64

Juju agent: 3.6.0

Charm revision: 526

LXD: 5.21.2 LTS

Log output

Juju debug log:

unit-postgresql-0: 14:40:27 ERROR unit.postgresql/0.juju-log Uncaught exception while in charm code:
Traceback (most recent call last):
  File "/var/lib/juju/agents/unit-postgresql-0/charm/./src/charm.py", line 1972, in <module>
    main(PostgresqlOperatorCharm)
  File "/var/lib/juju/agents/unit-postgresql-0/charm/venv/ops/__init__.py", line 343, in __call__
    return _main.main(charm_class=charm_class, use_juju_for_storage=use_juju_for_storage)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/var/lib/juju/agents/unit-postgresql-0/charm/venv/ops/_main.py", line 543, in main
    manager.run()
  File "/var/lib/juju/agents/unit-postgresql-0/charm/venv/ops/_main.py", line 529, in run
    self._emit()
  File "/var/lib/juju/agents/unit-postgresql-0/charm/venv/ops/_main.py", line 518, in _emit
    _emit_charm_event(self.charm, self.dispatcher.event_name, self._juju_context)
  File "/var/lib/juju/agents/unit-postgresql-0/charm/venv/ops/_main.py", line 134, in _emit_charm_event
    event_to_emit.emit(*args, **kwargs)
  File "/var/lib/juju/agents/unit-postgresql-0/charm/venv/ops/framework.py", line 347, in emit
    framework._emit(event)
  File "/var/lib/juju/agents/unit-postgresql-0/charm/venv/ops/framework.py", line 857, in _emit
    self._reemit(event_path)
  File "/var/lib/juju/agents/unit-postgresql-0/charm/venv/ops/framework.py", line 947, in _reemit
    custom_handler(event)
  File "/var/lib/juju/agents/unit-postgresql-0/charm/lib/charms/tempo_coordinator_k8s/v0/charm_tracing.py", line 1064, in wrapped_function
    return callable(*args, **kwargs)  # type: ignore
           ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/var/lib/juju/agents/unit-postgresql-0/charm/src/backups.py", line 988, in _on_list_backups_action
    formatted_list = self._generate_backup_list_output()
                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/var/lib/juju/agents/unit-postgresql-0/charm/lib/charms/tempo_coordinator_k8s/v0/charm_tracing.py", line 1064, in wrapped_function
    return callable(*args, **kwargs)  # type: ignore
           ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/var/lib/juju/agents/unit-postgresql-0/charm/src/backups.py", line 388, in _generate_backup_list_output
    backups = json.loads(output)[0]["backup"]
              ~~~~~~~~~~~~~~~~~~^^^
IndexError: list index out of range
unit-postgresql-0: 14:40:27 WARNING unit.postgresql/0.list-backups Uncaught IndexError in charm code: list index out of range
unit-postgresql-0: 14:40:27 WARNING unit.postgresql/0.list-backups Use `juju debug-log` to see the full traceback.

$ juju run postgresql/0 list-backups 
Running operation 5 with 1 task
  - task 6 on unit-postgresql-0

Waiting for task 6...
Action id 6 failed: exit status 1

Uncaught IndexError in charm code: list index out of range
Use `juju debug-log` to see the full traceback.

Additional context

[syncronize-issues-to-jira]

Thank you for reporting us your feedback!

The internal ticket has been created: https://warthogs.atlassian.net/browse/DPE-6231.

This message was autogenerated

[syncronize-issues-to-jira]

Thank you for reporting us your feedback!

The internal ticket has been created: https://warthogs.atlassian.net/browse/DPE-6232.

This message was autogenerated