Add a database last-modified-time

Add a new table which will have one record, simply containing the
last-modified-time of the database as a whole. Will be useful for
caching in the visualisation layer.

Create the table at startup in the main VLANd process if it doesn't
exist, and create the record too.
Add code to update the record on all other changes to the database.
Add code to report it through the daemon.status() API call.

Change-Id: I503c4371c04accb2c3f91adecc3e8a8a8614ea90

1 files changed, 1 insertions, 0 deletions

diff --git a/util.py b/util.py
index 9b30325..4c9816a 100644
--- a/util.py
+++ b/util.py
@@ -117,6 +117,7 @@ class VlanUtil:
             if command == 'daemon.status':
                 # data ignored
                 ret['running'] = 'ok'
+                ret['last_modified'] = state.db.get_last_modified_time()
             elif command == 'daemon.version':
                 # data ignored
                 ret['version'] = state.version