Export last frame timestamp metric

camdetect.py

@@ -13,6 +13,7 @@ from prometheus_client import Counter, Gauge
 from sanic import Sanic, response
 from sanic.response import stream
 from sanic_prometheus import monitor
+from time import time
 
 _, url = sys.argv
 
@@ -54,7 +55,9 @@ counter_errors = Counter(
 counter_movement_frames = Counter(
     "camdetect_movement_frames",
     "Frames with movement detected in them")
-
+gauge_last_frame = Gauge(
+    "camdetect_last_frame",
+    "Timestamp of last frame")
 gauge_total_blocks = Gauge(
     "camdetect_total_blocks",
     "Total DCT blocks")
@@ -86,6 +89,7 @@ async def client_connect(resp):
                 continue
             else:
                 app.ctx.last_frame = Frame(buf + data[:marker+2])
+                gauge_last_frame.set(time())
 
                 reference = app.ctx.last_frame.mask
                 app.ctx.frames.append(reference)