[maas] Support MAAS 3.5

In MAAS 3.5, system journal is used by all the services, therefore the
log size is significantly increased compared to the previous MAAS
versions. For snap this means that `journalctl` might need a long time
to collect and filter the log files before outputting them.

This sometimes leads to `maas` plugin timeouts with 3.5 snap, as `sos`
performs automatic log collection for services listed in `services`
tuple without any filters other than unit name, unless explicitly
specified by user. We want the plugin to work without additional params,
so we service declaration for 3.5 snap is ommitted. Instead,
`check_enabled` is used to activate the plugin. Logs are then collected
via `add_journal` call with a sane default limit to avoid timeouts.

Signed-off-by: Igor Brovtsin <[email protected]>

sos/report/plugins/maas.py

@@ -28,8 +28,14 @@ class Maas(Plugin, UbuntuPlugin):
         'maas-rackd',
         'maas-regiond',
         'maas-syslog',
-        # For the snap:
+        # MAAS 3.5 deb:
+        'maas-temporal',
+        'maas-apiserver',
+        'maas-agent',
+        # For the pre-3.5 snap:
         'snap.maas.supervisor',
+        # MAAS 3.5 snap uses `snap.maas.pebble` service, but it's not
+        # included here to prevent automatic journald log collection.
     )
 
     option_list = [
@@ -62,13 +68,25 @@ def _is_snap_installed(self):
             return maas_pkg['pkg_manager'] == 'snap'
         return False
 
+    def check_enabled(self):
+        return super().check_enabled() or self.is_service("snap.maas.pebble")
+
     def setup(self):
         self._is_snap = self._is_snap_installed()
         if self._is_snap:
             self.add_cmd_output([
                 'snap info maas',
                 'maas status'
             ])
+
+            if self.is_service("snap.maas.pebble"):
+                # Because `snap.maas.pebble` is not in the services
+                # tuple to prevent timeouts caused by log collection,
+                # service status and logs are collected here.
+                self.add_service_status("snap.maas.pebble")
+                since = self.get_option("since") or "-1days"
+                self.add_journal(units="snap.maas.pebble", since=since)
+
             # Don't send secrets
             self.add_forbidden_path("/var/snap/maas/current/bind/session.key")
             self.add_copy_spec([