Depracated blowfish cipher is causing errors in

Bug #1990992 reported by Moises Emilio Benzan Mora
This bug affects 1 person
Affects Status Importance Assigned to Milestone
Mert Kirpici

Bug Description

Charm juju-lint depends on Paramiko library for SSH connections; this library recently deprecated the Blowfish cypher that the charm currently uses, leading to the charm being stuck in the `error: config-changed hook`.

Stack trace:

unit-juju-lint-0: 23:00:03 ERROR unit.juju-lint/0.juju-log failed with this output:
/var/lib/juju/agents/unit-juju-lint-0/charm/venv/juju/ UserWarning: juju.loop module is being deprecated by 3.0, use juju.jasyncio instead
  warnings.warn('juju.loop module is being deprecated by 3.0, use juju.jasyncio instead')
/var/lib/juju/agents/unit-juju-lint-0/charm/venv/paramiko/ CryptographyDeprecationWarning: Blowfish has been deprecated
  "class": algorithms.Blowfish,
/tmp/ already exists, exiting

unit-juju-lint-0: 23:00:03 ERROR unit.juju-lint/0.juju-log Uncaught exception while in charm code:
Traceback (most recent call last):
  File "./src/", line 125, in <module>
  File "/var/lib/juju/agents/unit-juju-lint-0/charm/venv/ops/", line 431, in main
    _emit_charm_event(charm, dispatcher.event_name)
  File "/var/lib/juju/agents/unit-juju-lint-0/charm/venv/ops/", line 142, in _emit_charm_event
    event_to_emit.emit(*args, **kwargs)
  File "/var/lib/juju/agents/unit-juju-lint-0/charm/venv/ops/", line 283, in emit
  File "/var/lib/juju/agents/unit-juju-lint-0/charm/venv/ops/", line 743, in _emit
  File "/var/lib/juju/agents/unit-juju-lint-0/charm/venv/ops/", line 790, in _reemit
  File "./src/", line 91, in on_config_changed
  File "/var/lib/juju/agents/unit-juju-lint-0/charm/lib/", line 183, in run_auto_lint
    raise error
  File "/var/lib/juju/agents/unit-juju-lint-0/charm/lib/", line 173, in run_auto_lint
    subprocess.check_output([lint_script], stderr=subprocess.STDOUT).decode(
  File "/usr/lib/python3.8/", line 415, in check_output
    return run(*popenargs, stdout=PIPE, timeout=timeout, check=True,
  File "/usr/lib/python3.8/", line 516, in run
    raise CalledProcessError(retcode, process.args,
subprocess.CalledProcessError: Command '['/usr/local/bin/']' returned non-zero exit status 1.
unit-juju-lint-0: 23:00:04 ERROR juju.worker.uniter.operation hook "config-changed" (via hook dispatching script: dispatch) failed: exit status 1

Relevant run:

Run artifacts:

Eric Chen (eric-chen)
tags: added: bseng-437
Revision history for this message
Mert Kirpici (mertkirpici) wrote :

I think this particular exception is not caused by the Blowfish cipher deprecation output(which was probably a warning). The line that carries the fatal information is:

> /tmp/ already exists, exiting

Which is coming from the code block that ensures there's only one instance of the `` process executing at any given moment. Usually this script is run on a cronjob, which is installed to the system during the install hook of the juju-lint charm. I said "usually" because there are two instances where this script is run as a subprocess by the charm itself:
1 - during install: after the cronjob installation is completed, the script is run once.
2 - during config-changed.

Since we are seeing this as an exception in the charm logs, I think one of the above event handlers were running while the cronjob had already been triggered before and it was still running.

Changed in charm-juju-lint:
assignee: nobody → Mert Kirpici (mertkirpici)
Revision history for this message
Mert Kirpici (mertkirpici) wrote :

Created LP #1991897

Marking this as invalid since the issue is not related to the Blowfish cipher warning.

Changed in charm-juju-lint:
status: New → Invalid
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