blueprints.api: add calc_uptime, uptime field on api

elstat/blueprints/api.py

@@ -1,3 +1,4 @@
+from decimal import Decimal
 from sanic import Blueprint, response
 
 bp = Blueprint(__name__)
@@ -42,10 +43,51 @@ def get_graphs(manager):
     return res
 
 
+def calc_uptime(manager):
+    res = {}
+
+    for name, worker in manager.workers.items():
+        cur = manager.conn.cursor()
+
+        # get total period we've been polling the service
+        cur.execute(f"""
+        SELECT min(timestamp), max(timestamp) from {name}
+        """)
+
+        row = cur.fetchone()
+        min_tstamp, max_tstamp = row[0], row[1]
+        t_period = max_tstamp - min_tstamp
+
+        # get all polls that failed
+        cur.execute(f"""
+        SELECT COUNT(*) FROM {name}
+        WHERE status = false
+        """)
+
+        row = cur.fetchone()
+        down_hits = row[0]
+
+        # total downtime in seconds
+        downtime = down_hits * worker.service['poll']
+
+        # calculate total downtime in percentage
+        percent = Decimal(downtime) / Decimal(t_period)
+
+        # uptime - downtime = real uptime
+        res[name] = str(Decimal(100) - percent)
+
+    return res
+
+
 @bp.get('/api/current_status')
 async def get_cur_status(request):
     manager = request.app.manager
-    return response.json(get_status(manager))
+    return response.json({
+        **get_status(manager),
+        **{
+            'uptime': calc_uptime(manager)
+        }
+    })
 
 
 @bp.get('/api/status')
@@ -55,4 +97,5 @@ async def get_full_status(request):
     return response.json({
         'status': get_status(manager),
         'graph': get_graphs(manager),
+        'uptime': calc_uptime(manager)
     })