service is_enabled does not work with exit code 4

[pfuntner]

I'm finding that when systemctl is-enabled is used for a non-existent service and the target has an exit code of 4 (such as on an Ubuntu 24 target), an exception is raised.

pytest script

(venv) $ cat service-test.py
def test_faux_service(host):
        assert not host.service('foo').is_enabled
(venv) $

Ubuntu 24

(venv) $ pytest --hosts ubuntu24 service-test.py
==================================================================================== test session starts =====================================================================================
platform linux -- Python 3.11.0rc1, pytest-8.3.5, pluggy-1.5.0
rootdir: /home/jpfuntne/sto/issues/CL9-746
plugins: testinfra-10.2.2
collected 1 item

service-test.py F                                                                                                                                                                      [100%]

========================================================================================== FAILURES ==========================================================================================
___________________________________________________________________________ test_faux_service[paramiko://ubuntu24] ___________________________________________________________________________

host = <testinfra.host.Host paramiko://ubuntu24>

    def test_faux_service(host):
>       assert not host.service('foo').is_enabled

service-test.py:2:
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
venv/lib/python3.11/site-packages/testinfra/modules/service.py:197: in is_enabled
    cmd = self.run_test("systemctl is-enabled %s", self.name)
venv/lib/python3.11/site-packages/testinfra/modules/base.py:40: in run_test
    return cls._host.run_test(*args, **kwargs)
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

self = <testinfra.host.Host paramiko://ubuntu24>, command = 'systemctl is-enabled %s', args = ('foo',), kwargs = {}

    def run_test(
        self, command: str, *args: str, **kwargs: Any
    ) -> testinfra.backend.base.CommandResult:
        """Run command and check it return an exit status of 0 or 1

        :raises: AssertionError
        """
>       return self.run_expect([0, 1], command, *args, **kwargs)
E       AssertionError: Unexpected exit code 4 for CommandResult(backend=<testinfra.backend.paramiko.ParamikoBackend object at 0x7f4b7768b490>, exit_status=4, command=b'systemctl is-enabled foo', _stdout=b'not-found\n', _stderr=b'')
E       assert 4 in [0, 1]
E        +  where 4 = CommandResult(backend=<testinfra.backend.paramiko.ParamikoBackend object at 0x7f4b7768b490>, exit_status=4, command=b'systemctl is-enabled foo', _stdout=b'not-found\n', _stderr=b'').rc

venv/lib/python3.11/site-packages/testinfra/host.py:120: AssertionError
====================================================================================== warnings summary ======================================================================================
service-test.py::test_faux_service[paramiko://ubuntu24]
  /home/jpfuntne/sto/issues/CL9-746/venv/lib/python3.11/site-packages/paramiko/client.py:889: UserWarning: Unknown ssh-ed25519 host key for 34.74.229.204: b'96b278a4e66eefe2941f43fa809646db'
    warnings.warn(

-- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html
================================================================================== short test summary info ===================================================================================
FAILED service-test.py::test_faux_service[paramiko://ubuntu24] - AssertionError: Unexpected exit code 4 for CommandResult(backend=<testinfra.backend.paramiko.ParamikoBackend object at 0x7f4b7768b490>, exit_status=4, command=b'systemctl is-enabled foo...
================================================================================ 1 failed, 1 warning in 1.46s ================================================================================
(venv) $ ssh ubuntu24 'systemctl is-enabled foo; echo $?'
not-found
4
(venv) $ ssh ubuntu24 cat /etc/os-release
PRETTY_NAME="Ubuntu 24.04.2 LTS"
NAME="Ubuntu"
VERSION_ID="24.04"
VERSION="24.04.2 LTS (Noble Numbat)"
VERSION_CODENAME=noble
ID=ubuntu
ID_LIKE=debian
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
UBUNTU_CODENAME=noble
LOGO=ubuntu-logo
(venv) $

Ubuntu 22

This is not a problem on Ubuntu 22 which has an exit code of 1 in the same scenario:

(venv) $ pytest --hosts ubuntu22 service-test.py
==================================================================================== test session starts =====================================================================================
platform linux -- Python 3.11.0rc1, pytest-8.3.5, pluggy-1.5.0
rootdir: /home/jpfuntne/sto/issues/CL9-746
plugins: testinfra-10.2.2
collected 1 item

service-test.py .                                                                                                                                                                      [100%]

====================================================================================== warnings summary ======================================================================================
service-test.py::test_faux_service[paramiko://ubuntu22]
  /home/jpfuntne/sto/issues/CL9-746/venv/lib/python3.11/site-packages/paramiko/client.py:889: UserWarning: Unknown ssh-ed25519 host key for 35.185.104.216: b'232b368a904a128f57b7601d1faeb172'
    warnings.warn(

-- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html
================================================================================ 1 passed, 1 warning in 1.48s ================================================================================
(venv) $ ssh ubuntu22 'systemctl is-enabled foo; echo $?'
1
Failed to get unit file state for foo.service: No such file or directory
(venv) $ ssh ubuntu22 cat /etc/os-release
PRETTY_NAME="Ubuntu 22.04.5 LTS"
NAME="Ubuntu"
VERSION_ID="22.04"
VERSION="22.04.5 LTS (Jammy Jellyfish)"
VERSION_CODENAME=jammy
ID=ubuntu
ID_LIKE=debian
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
UBUNTU_CODENAME=jammy
(venv) $

This is similar to #748 which I hoped would be fixed by #773 but it was not.

Python packages

(venv) $ pip list
Package          Version
---------------- -------
bcrypt           4.3.0
cffi             1.17.1
cryptography     44.0.2
iniconfig        2.1.0
packaging        24.2
paramiko         3.5.1
pip              22.0.2
pluggy           1.5.0
pycparser        2.22
PyNaCl           1.5.0
pytest           8.3.5
pytest-testinfra 10.2.2
setuptools       59.6.0
(venv) $

[pfuntner]

I've suggested a fix with #802