add pdns networks

docker-compose.slave.yml

@@ -65,6 +65,8 @@ services:
     volumes: # Storage can be either a
       - nginx_secrets:/etc/letsencrypt          # Docker managed volume (see list at the bottom)
       - nginx_conf:/etc/nginx/user_conf.d    # or a host mount with a relative or full path.
+    networks:
+      - pdns_network
 
 volumes:
   mariadb_data: