Prefer resolvectl over systemd-resolve

The latter is a deprecated compat symlink.

See https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=979264

Signed-off-by: Michael Biebl <biebl@debian.org>

sos/report/plugins/systemd.py

@@ -21,6 +21,8 @@ class Systemd(Plugin, IndependentPlugin):
     packages = ('systemd',)
     files = ('/run/systemd/system',)
 
+    resolvectl = 'resolvectl' if self.is_executable('resolvectl') else 'systemd-resolve'
+
     def setup(self):
         self.add_cmd_output([
             "systemctl status --all",
@@ -47,11 +49,11 @@ def setup(self):
             "timedatectl"
         ])
 
-        # systemd-resolve command starts systemd-resolved service if that
+        # resolvectl command starts systemd-resolved service if that
         # is not running, so gate the commands by this predicate
         self.add_cmd_output([
-            "systemd-resolve --status",
-            "systemd-resolve --statistics",
+            "%s status" % resolvectl,
+            "%s statistics" % resolvectl,
         ], pred=SoSPredicate(self, services=["systemd-resolved"]))
 
         self.add_cmd_output("systemd-analyze plot",