fix: report which services are enabled, and whether an action worked

get_services() read list-unit-files' second column, which since systemd 245
is followed by a preset column -- "enabled  enabled" never equalled
"enabled", so every service on every node was reported disabled (#6).
manage_service() ended in "|| true" and returned success whatever happened.

Both now come from napalm-device-types' SystemdServicesMixin (2.2.0): the
enabled state is UnitFileState from systemctl show, MainPID comes along in
the same round trip, and an action reports systemctl's exit status. The
driver keeps only _run_service_command(), its exec path as root. The exit
status marker keeps the output non-empty, so _exec_ssh_command's SSH fallback
on an empty API answer can no longer run an action twice.

The listing no longer includes templates, static unit files and aliases that
are not loaded (on a PVE 9 node: 280 entries -> 172).

Closes #6

tests/test_services.py

@@ -0,0 +1,68 @@
+"""Services on a Proxmox node: systemd, through napalm-device-types' mixin.
+
+The listing used to read ``list-unit-files``' second column, which since
+systemd 245 is followed by a preset column -- so ``enabled`` was false for
+every service on every node (#6). An action ended in ``|| true`` and reported
+success whatever happened. Both now come from the shared mixin; the driver
+only carries the command over its exec path, as root.
+"""
+
+from __future__ import annotations
+
+from unittest.mock import patch
+
+import pytest
+from napalm_device_types import SystemdServicesMixin
+from napalm_device_types.systemd import SYSTEMD_SERVICES_COMMAND, service_action_command
+
+from napalm_proxmox.driver import ProxmoxDriver
+
+REPORT = (
+    "SVC_BEGIN\n[files]\npveproxy.service enabled enabled\n[units]\n"
+    "MainPID=1234\nId=pveproxy.service\nNames=pveproxy.service\nLoadState=loaded\n"
+    "ActiveState=active\nSubState=running\nUnitFileState=enabled\n"
+    "[generated]\nSVC_END\n"
+)
+
+
+def test_the_driver_uses_the_shared_mixin():
+    assert issubclass(ProxmoxDriver, SystemdServicesMixin)
+    assert ProxmoxDriver.get_services is SystemdServicesMixin.get_services
+    assert ProxmoxDriver.manage_service is SystemdServicesMixin.manage_service
+
+
+def test_listing_runs_the_shared_command(driver):
+    with patch.object(driver, "_exec_ssh_command", return_value=REPORT) as exec_:
+        services = driver.get_services()
+
+    exec_.assert_called_once_with(SYSTEMD_SERVICES_COMMAND)
+    assert services == [{"name": "pveproxy", "running": True, "enabled": True, "pid": 1234}]
+
+
+def test_an_unreadable_listing_raises_instead_of_reporting_no_services(driver):
+    with patch.object(driver, "_exec_ssh_command", return_value=""):
+        with pytest.raises(ValueError):
+            driver.get_services()
+
+
+def test_an_action_reports_its_real_outcome(driver):
+    failed = "Failed to restart nope.service: Unit nope.service not found.\n__SVC_RC=5"
+    with patch.object(driver, "_exec_ssh_command", return_value=failed) as exec_:
+        result = driver.manage_service("nope", "restart")
+
+    exec_.assert_called_once_with(service_action_command("nope", "restart"))
+    assert result["success"] is False
+    assert "not found" in result["output"]
+
+
+def test_a_successful_action(driver):
+    with patch.object(driver, "_exec_ssh_command", return_value="__SVC_RC=0"):
+        assert driver.manage_service("pveproxy", "restart") == {"success": True, "output": ""}
+
+
+def test_an_invalid_name_never_reaches_the_node(driver):
+    with patch.object(driver, "_exec_ssh_command") as exec_:
+        with pytest.raises(ValueError):
+            driver.manage_service("pveproxy; reboot", "stop")
+
+    exec_.assert_not_called()