Jhack exception if no SSH access to Juju unit (default in Juju 4+) #234
Description
Bug Description
Hi,
usage jhack on default Juju 4 deployment generates a complex trace due to lack of unit access (SSH is not configured by default).
To Reproduce
juju version # 4.0.1-genericlinux-amd64
juju add-model test
juju deploy hello-juju
jhack fire hello-juju/0 update-status
hello-juju/0 update-status
╭───────────────────────────────────────────────────────────────────────────────────────────────────────── Traceback (most recent call last) ──────────────────────────────────────────────────────────────────────────────────────────────────────────╮
│ /snap/jhack/601/lib/python3.12/site-packages/jhack/utils/simulate_event.py:570 in simulate_event │
│ │
│ 567 │ Especially useful in combination with jhack charm sync and/or debug-code/debug-hooks ╭───────────── locals ──────────────╮ │
│ 568 │ """ │ check_name = None │ │
│ 569 │ print(target, event) │ dry_run = None │ │
│ ❱ 570 │ return _simulate_event( │ env_override = None │ │
│ 571 │ │ target, │ event = 'update-status' │ │
│ 572 │ │ event, │ model = None │ │
│ 573 │ │ relation_remote=relation_remote, │ notice_id = None │ │
│ │ parallel = None │ │
│ │ relation_id = None │ │
│ │ relation_remote = None │ │
│ │ secret = None │ │
│ │ show_output = True │ │
│ │ target = 'hello-juju/0' │ │
│ ╰───────────────────────────────────╯ │
│ │
│ /snap/jhack/601/lib/python3.12/site-packages/jhack/utils/simulate_event.py:421 in _simulate_event │
│ │
│ 418 │ if not targets: ╭───────────────── locals ─────────────────╮ │
│ 419 │ │ sys.exit(f"invalid target: {target!r} not found in {model or '<the current model │ check_name = None │ │
│ 420 │ │ dry_run = None │ │
│ ❱ 421 │ cmds = tuple( │ emit_juju_log = True │ │
│ 422 │ │ _build_command( │ env_override = None │ │
│ 423 │ │ │ unit=unit_name, │ event = 'update-status' │ │
│ 424 │ │ │ event=event, │ model = None │ │
│ │ notice_id = None │ │
│ │ operator_dispatch = False │ │
│ │ parallel = None │ │
│ │ print_captured_stderr = True │ │
│ │ print_captured_stdout = True │ │
│ │ relation_id = None │ │
│ │ relation_remote = None │ │
│ │ secret_id_or_label = None │ │
│ │ target = 'hello-juju/0' │ │
│ │ targets = ['hello-juju/0'] │ │
│ ╰──────────────────────────────────────────╯ │
│ │
│ /snap/jhack/601/lib/python3.12/site-packages/jhack/utils/simulate_event.py:433 in <genexpr> │
│ │
│ 430 │ │ │ secret_id_or_label=secret_id_or_label, ╭─────────────────────────── locals ────────────────────────────╮ │
│ 431 │ │ │ operator_dispatch=operator_dispatch, │ .0 = <list_iterator object at 0x70339f4cdea0> │ │
│ 432 │ │ │ env_override=env_override, │ check_name = None │ │
│ ❱ 433 │ │ │ has_dispatch=is_dispatch_aware(unit_name, model), │ env_override = None │ │
│ 434 │ │ ) │ event = 'update-status' │ │
│ 435 │ │ for unit_name in targets │ model = None │ │
│ 436 │ ) │ notice_id = None │ │
│ │ operator_dispatch = False │ │
│ │ relation_id = None │ │
│ │ relation_remote = None │ │
│ │ secret_id_or_label = None │ │
│ │ unit_name = 'hello-juju/0' │ │
│ ╰───────────────────────────────────────────────────────────────╯ │
│ │
│ /snap/jhack/601/lib/python3.12/site-packages/jhack/helpers.py:279 in is_dispatch_aware │
│ │
│ 276 │ except CalledProcessError as e: ╭────────────────────────────────────────────── locals ──────────────────────────────────────────────╮ │
│ 277 │ │ if e.returncode == 1: │ _model = '' │ │
│ 278 │ │ │ return False │ cmd = 'juju ssh hello-juju/0 cat /var/lib/juju/agents/unit-hello-juju-0/charm/dispatch' │ │
│ ❱ 279 │ │ raise e │ model = None │ │
│ 280 │ unit = 'hello-juju/0' │ │
│ 281 │ unit_sanitized = 'unit-hello-juju-0' │ │
│ 282 @contextlib.contextmanager ╰────────────────────────────────────────────────────────────────────────────────────────────────────╯ │
│ │
│ /snap/jhack/601/lib/python3.12/site-packages/jhack/helpers.py:274 in is_dispatch_aware │
│ │
│ 271 │ cmd = f"juju ssh{_model} {unit} cat /var/lib/juju/agents/{unit_sanitized}/charm/disp ╭────────────────────────────────────────────── locals ──────────────────────────────────────────────╮ │
│ 272 │ logger.debug(f"running {cmd}") │ _model = '' │ │
│ 273 │ try: │ cmd = 'juju ssh hello-juju/0 cat /var/lib/juju/agents/unit-hello-juju-0/charm/dispatch' │ │
│ ❱ 274 │ │ check_call(shlex.split(cmd), stdout=PIPE, stderr=PIPE) │ model = None │ │
│ 275 │ │ return True │ unit = 'hello-juju/0' │ │
│ 276 │ except CalledProcessError as e: │ unit_sanitized = 'unit-hello-juju-0' │ │
│ 277 │ │ if e.returncode == 1: ╰────────────────────────────────────────────────────────────────────────────────────────────────────╯ │
│ │
│ /usr/lib/python3.12/subprocess.py:413 in check_call │
│ │
│ 410 │ │ cmd = kwargs.get("args") ╭──────────────────────────────────────────────────── locals ────────────────────────────────────────────────────╮ │
│ 411 │ │ if cmd is None: │ cmd = ['juju', 'ssh', 'hello-juju/0', 'cat', '/var/lib/juju/agents/unit-hello-juju-0/charm/dispatch'] │ │
│ 412 │ │ │ cmd = popenargs[0] │ kwargs = {'stdout': -1, 'stderr': -1} │ │
│ ❱ 413 │ │ raise CalledProcessError(retcode, cmd) │ popenargs = (['juju', 'ssh', 'hello-juju/0', 'cat', '/var/lib/juju/agents/unit-hello-juju-0/charm/dispatch'],) │ │
│ 414 │ return 0 │ retcode = 255 │ │
│ 415 ╰────────────────────────────────────────────────────────────────────────────────────────────────────────────────╯ │
│ 416 │
╰──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────╯
CalledProcessError: Command '['juju', 'ssh', 'hello-juju/0', 'cat', '/var/lib/juju/agents/unit-hello-juju-0/charm/dispatch']' returned non-zero exit status 255.
ubuntu@juju400:~$
Fix:
ssh-keygen -b 4096
juju add-ssh-key "$(cat ~/.ssh/id_ed25519.pub)"
jhack fire hello-juju/0 update-status # produces no more exception.
Environment
jhack 0.4.4.0.24 601 latest/edge ppasotti -
juju 4.0.1-63a1d56 33390 4.0/edge canonical✓ -
lxd 6.5-ccdfb39 36020 latest/stable canonical✓ -
Relevant log output
See aboveAdditional context
No response