bundles/{systemd,hostname}: add hostname control

bundles/systemd/items.py

@@ -3,5 +3,16 @@ actions = {
         'command': '/usr/bin/systemctl daemon-reload',
         'cascade_skip': False,
         'triggered': True,
+        'needed_by': {
+            'svc_systemd:',
+        },
+    },
+    'systemd-hostname': {
+        'command': 'hostnamectl set-hostname {}'.format(node.hostname),
+        'unless': '[ "$(hostnamectl --static)" = "{}" ]'.format(node.hostname),
+        # Provided by 'hostname' bundle
+        'needs': {
+            'file:/etc/hosts',
+        },
     },
 }