docs(debug): Explain UFS_LOGLEVEL env var

README.md

@@ -76,6 +76,14 @@ dnf -y install dbus-glib-devel dbus-devel
 
 This script assumes write access to `firewalld` direct rules file `/etc/firewalld/direct.xml` or whereever else you've configured this file to live. Typically that means you're going to want to run UFS as `root`.
 
+UFS understands the environment variable `UFS_LOGLEVEL` to set its log verbosity. `UFS_LOGLEVEL` defaults to `INFO`, for more verbosity change it to `DEBUG`, for less change it to either `WARNING` or even just `ERROR`. The example systemd `.service` file in ['examples' directory](examples) makes use of the following decleration:
+
+```
+Environment='...' 'UFS_LOGLEVEL=INFO'
+```
+
+Since `UFS_LOGLEVEL=INFO` is default anyway this particular example is redundant and serves as starting point for you.
+
 # Config structure
 
 Package configuration happens via a `config.ini` file that follows INI-style syntax. Copy [examples/config.ini.example](examples/config.ini.example) to `config.ini` to get started:

update-firewall-source.py

@@ -523,14 +523,14 @@ def write_new_fwd_direct_xml(
 
 def restart_systemd_firewalld() -> bool:
     sysbus = dbus.SystemBus()
-    systemd1 = sysbus.get_object('org.freedesktop.systemd1', '/org/freedesktop/systemd1')
-    manager = dbus.Interface(systemd1, 'org.freedesktop.systemd1.Manager')
+    systemd1 = sysbus.get_object("org.freedesktop.systemd1", "/org/freedesktop/systemd1")
+    manager = dbus.Interface(systemd1, "org.freedesktop.systemd1.Manager")
 
-    firewalld_unit = manager.LoadUnit('firewalld.service')
-    firewalld_proxy = sysbus.get_object('org.freedesktop.systemd1', str(firewalld_unit))
-    firewalld_active_state = firewalld_proxy.Get('org.freedesktop.systemd1.Unit',
-                                                 'ActiveState',
-                                                 dbus_interface='org.freedesktop.DBus.Properties')
+    firewalld_unit = manager.LoadUnit("firewalld.service")
+    firewalld_proxy = sysbus.get_object("org.freedesktop.systemd1", str(firewalld_unit))
+    firewalld_active_state = firewalld_proxy.Get("org.freedesktop.systemd1.Unit",
+                                                 "ActiveState",
+                                                 dbus_interface="org.freedesktop.DBus.Properties")
 
     if firewalld_active_state == "inactive":
         log.info(f"systemd firewalld.service unit is inactive, ignoring restart instruction, leaving as-is ...")
@@ -599,7 +599,7 @@ def has_xml_changed(
             return False
 
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     validate_default_section(config)
     if config_has_valid_section(config):
         validate_config_sections(config)