Adding db health checks.

apps/static/views.py

@@ -1,9 +1,12 @@
 import os
 import yaml
+import redis
 from django.conf import settings
 from django.http import HttpResponse
 from django.shortcuts import render_to_response
 from django.template import RequestContext
+from apps.rss_feeds.models import Feed, MStory
+from apps.search.models import SearchFeed
 from utils import log as logging
 
 def about(request):
@@ -65,3 +68,35 @@ def ios_ipa(request):
 
 def haproxy_check(request):
     return HttpResponse("OK")
+
+def postgres_check(request):
+    feed = Feed.objects.latest('pk').pk
+    if feed:
+        return HttpResponse(unicode(feed))
+    assert False, "Cannot read from postgres database"
+
+def mongo_check(request):
+    stories = MStory.objects.count()
+    if stories:
+        return HttpResponse(unicode(stories))
+    assert False, "Cannot read from mongo database"
+
+def elasticsearch_check(request):
+    client = SearchFeed.ES()
+    if client.indices.exists_index(SearchFeed.index_name()):
+        return HttpResponse(SearchFeed.index_name())
+    assert False, "Cannot read from elasticsearch database"
+
+def redis_check(request):
+    pool = request.GET['pool']
+    if pool == 'main':
+        r = redis.Redis(connection_pool=settings.REDIS_POOL)
+    elif pool == 'story':
+        r = redis.Redis(connection_pool=settings.REDIS_STORY_HASH_POOL)
+    elif pool == 'sessions':
+        r = redis.Redis(connection_pool=settings.REDIS_SESSION_POOL)
+        
+    key = r.randomkey()
+    if key:
+        return HttpResponse(unicode(key))
+    assert False, "Cannot read from redis-%s database" % pool

config/debug_haproxy.conf

@@ -92,7 +92,32 @@ backend maintenance
   http-check expect status 404
   http-check send-state
   server nginxdebug 127.0.0.1:81     check inter 2000ms
-  
+ 
+backend postgres
+  option httpchk GET /_dbcheck/postgres
+  timeout 5s
+  server postgres-db01  127.0.0.1:8888   check inter 2000ms
+backend mongo
+  option httpchk GET /_dbcheck/mongo
+  timeout 5s
+  server mongo-db22  127.0.0.1:8888   check inter 2000ms
+backend redis
+  option httpchk GET /_dbcheck/redis?pool=main
+  timeout 5s
+  server redis-db40  127.0.0.1:8888   check inter 2000ms
+backend redis_story
+  option httpchk GET /_dbcheck/redis?pool=story
+  timeout 5s
+  server redis-db41  127.0.0.1:8888   check inter 2000ms
+backend redis_sessions
+  option httpchk GET /_dbcheck/redis?pool=sessions
+  timeout 5s
+  server redis-db42  127.0.0.1:8888   check inter 2000ms
+backend elasticsearch
+  option httpchk GET /_dbcheck/elasticsearch
+  timeout 5s
+  server elasticsearch-db10  127.0.0.1:8888   check inter 2000ms
+
 frontend stats
   bind :1936 ssl crt newsblur.pem
   default_backend stats

urls.py

@@ -37,6 +37,10 @@ urlpatterns = patterns('',
     (r'^push/',             include('apps.push.urls')),
     (r'^categories/',       include('apps.categories.urls')),
     (r'^_haproxychk',       static_views.haproxy_check),
+    (r'^_dbcheck/postgres', static_views.postgres_check),
+    (r'^_dbcheck/mongo',    static_views.mongo_check),
+    (r'^_dbcheck/redis',    static_views.redis_check),
+    (r'^_dbcheck/elasticsearch', static_views.elasticsearch_check),
     url(r'^admin/',         include(admin.site.urls)),
     url(r'^about/?',        static_views.about, name='about'),
     url(r'^faq/?',          static_views.faq, name='faq'),