ads: Add endpoint for health check on ads

Adds a new route /health/ads which returns in plain text the seconds
since the epoch that the ad system was last updated via make_daily_promotions()

r2/r2/config/routing.py

@@ -158,6 +158,7 @@ def make_map():
     mc('/promoted/', controller='promoted', action="listing", sort="")
 
     mc('/health', controller='health', action='health')
+    mc('/health/ads', controller='health', action='promohealth')
 
     mc('/', controller='hot', action='listing')
 

r2/r2/controllers/health.py

@@ -30,6 +30,7 @@ from pylons import c, g, response
 
 from reddit_base import MinimalController
 from r2.lib.amqp import worker
+from r2.lib import promote
 
 from validator import *
 
@@ -47,3 +48,7 @@ class HealthController(MinimalController):
         c.dontcache = True
         response.headers['Content-Type'] = 'text/plain'
         return json.dumps(g.versions, sort_keys=True, indent=4)
+
+    def GET_promohealth(self):
+        response.headers['Content-Type'] = 'text/plain'
+        return json.dumps(promote.health_check())

r2/r2/lib/promote.py

@@ -23,9 +23,11 @@
 from __future__ import with_statement
 
 import json
+import time
 
 from r2.models import *
 from r2.models.bidding import SponsorBoxWeightings, WeightingRef
+from r2.models.keyvalue import NamedGlobals
 from r2.lib.wrapped import Wrapped
 from r2.lib import authorize
 from r2.lib import emailer, filters
@@ -54,6 +56,16 @@ CAMPAIGN = Enum("start", "end", "bid", "sr", "trans_id")
 UPDATE_QUEUE = 'update_promos_q'
 QUEUE_ALL = 'all'
 
+PROMO_HEALTH_KEY = 'promotions_last_updated'
+
+
+def _mark_promos_updated():
+    NamedGlobals.set(PROMO_HEALTH_KEY, time.time())
+
+
+def health_check():
+    return NamedGlobals.get(PROMO_HEALTH_KEY, default=0)
+
 
 @memoize("get_promote_srid")
 def get_promote_srid(name = 'promos'):
@@ -831,6 +843,7 @@ def make_daily_promotions(offset = 0, test = False):
 
     if not test:
         set_live_promotions(all_links, weighted)
+        _mark_promos_updated()
     else:
         print (all_links, weighted)