bundles/pppd: make sure dependent services are stopped before restarting pppoe session

bundles/wide-dhcp6c/metadata.py

@@ -16,3 +16,17 @@ defaults = {
         'subnet_len': '8',
     },
 }
+
+
+@metadata_reactor
+def pppd(metadata):
+    if metadata.get('wide-dhcp6c/integrate-with-pppd', False):
+        return {
+            'pppd': {
+                'wait-until-stopped': {
+                    'wide-dhcpv6-client.service',
+                },
+            }
+        }
+
+    return {}