Merge autopkgtest-cloud:dont-fail-on-reset into autopkgtest-cloud:master

[Brian Murray]

When adding a new lxd-armhf runner I encountered the following error:

2022-08-05 17:02:14 DEBUG unit.autopkgtest-lxd-worker/0.config-changed logger.go:60 calling DisableUnitFiles then StopUnit on ['<email address hidden>']
2022-08-05 17:02:15 WARNING unit.autopkgtest-lxd-worker/0.config-changed logger.go:60 Traceback (most recent call last):
2022-08-05 17:02:15 WARNING unit.autopkgtest-lxd-worker/0.config-changed logger.go:60 File "/var/lib/juju/agents/unit-autopkgtest-lxd-worker-0/charm/hooks/config-changed", line 22, in <module>
2022-08-05 17:02:15 WARNING unit.autopkgtest-lxd-worker/0.config-changed logger.go:60 main()
2022-08-05 17:02:15 WARNING unit.autopkgtest-lxd-worker/0.config-changed logger.go:60 File "/var/lib/juju/agents/unit-autopkgtest-lxd-worker-0/.venv/lib/python3.8/site-packages/charms/reactive/__init__.py", line 74, in main
2022-08-05 17:02:15 WARNING unit.autopkgtest-lxd-worker/0.config-changed logger.go:60 bus.dispatch(restricted=restricted_mode)
2022-08-05 17:02:15 WARNING unit.autopkgtest-lxd-worker/0.config-changed logger.go:60 File "/var/lib/juju/agents/unit-autopkgtest-lxd-worker-0/.venv/lib/python3.8/site-packages/charms/reactive/bus.py", line 390, in dispatch
2022-08-05 17:02:15 WARNING unit.autopkgtest-lxd-worker/0.config-changed logger.go:60 _invoke(other_handlers)
2022-08-05 17:02:15 WARNING unit.autopkgtest-lxd-worker/0.config-changed logger.go:60 File "/var/lib/juju/agents/unit-autopkgtest-lxd-worker-0/.venv/lib/python3.8/site-packages/charms/reactive/bus.py", line 359, in _invoke
2022-08-05 17:02:15 WARNING unit.autopkgtest-lxd-worker/0.config-changed logger.go:60 handler.invoke()
2022-08-05 17:02:15 WARNING unit.autopkgtest-lxd-worker/0.config-changed logger.go:60 File "/var/lib/juju/agents/unit-autopkgtest-lxd-worker-0/.venv/lib/python3.8/site-packages/charms/reactive/bus.py", line 181, in invoke
2022-08-05 17:02:15 WARNING unit.autopkgtest-lxd-worker/0.config-changed logger.go:60 self._action(*args)
2022-08-05 17:02:15 WARNING unit.autopkgtest-lxd-worker/0.config-changed logger.go:60 File "/var/lib/juju/agents/unit-autopkgtest-lxd-worker-0/charm/reactive/autopkgtest_cloud_worker.py", line 316, in enable_disable_units
2022-08-05 17:02:15 WARNING unit.autopkgtest-lxd-worker/0.config-changed logger.go:60 set_up_systemd_units(
2022-08-05 17:02:15 WARNING unit.autopkgtest-lxd-worker/0.config-changed logger.go:60 File "/var/lib/juju/agents/unit-autopkgtest-lxd-worker-0/charm/lib/systemd.py", line 370, in set_up_systemd_units
2022-08-05 17:02:15 WARNING unit.autopkgtest-lxd-worker/0.config-changed logger.go:60 disable(unit_names)
2022-08-05 17:02:15 WARNING unit.autopkgtest-lxd-worker/0.config-changed logger.go:60 File "/var/lib/juju/agents/unit-autopkgtest-lxd-worker-0/charm/lib/systemd.py", line 90, in disable
2022-08-05 17:02:15 WARNING unit.autopkgtest-lxd-worker/0.config-changed logger.go:60 SYSTEM_BUS.call_sync(
2022-08-05 17:02:15 WARNING unit.autopkgtest-lxd-worker/0.config-changed logger.go:60 gi.repository.GLib.Error: g-io-error-quark: GDBus.Error:org.freedesktop.systemd1.NoSuchUnit: Unit <email address hidden> not loaded. (36)

If the unit isn't loaded I don't think this needs to stop the charm from running but I'm not entirely certain how reactive charms work so ICBW.

[Brian Murray (brian-murray)]

I cowboy'ed this change on the autopkgtest-lxd-worker without any issues.

[Paride Legovini (paride)]

This LGTM, thanks!

review: Approve

diff --git a/charms/focal/autopkgtest-cloud-worker/lib/systemd.py b/charms/focal/autopkgtest-cloud-worker/lib/systemd.py
index 8c9856e..8eed044 100644
--- a/charms/focal/autopkgtest-cloud-worker/lib/systemd.py
+++ b/charms/focal/autopkgtest-cloud-worker/lib/systemd.py
@@ -87,17 +87,20 @@ def disable(unit_names):
         "StopUnit",
     )
     for unit in unit_names:
-        SYSTEM_BUS.call_sync(
-            "org.freedesktop.systemd1",
-            "/org/freedesktop/systemd1",
-            "org.freedesktop.systemd1.Manager",
-            "ResetFailedUnit",
-            GLib.Variant("(s)", (unit,)),
-            None,  # reply type
-            Gio.DBusCallFlags.NONE,
-            -1.0,  # timeout
-            None,
-        )  # cancellable
+        try:
+            SYSTEM_BUS.call_sync(
+                "org.freedesktop.systemd1",
+                "/org/freedesktop/systemd1",
+                "org.freedesktop.systemd1.Manager",
+                "ResetFailedUnit",
+                GLib.Variant("(s)", (unit,)),
+                None,  # reply type
+                Gio.DBusCallFlags.NONE,
+                -1.0,  # timeout
+                None,
+            )  # cancellable
+        except GLib.Error:
+            pass
         try:
             dropindir = os.path.join(
                 os.path.sep, "etc", "systemd", "system", "{}.d".format(unit)