Merge pull request #59 from edx/health-page-fix

Returning HTTP 503 if service is unhealthy

analyticsdataserver/tests.py

@@ -46,7 +46,7 @@ class OperationalEndpointsTest(TestCaseWithAuthentication):
     def test_health(self):
         self.assert_database_health('OK')
 
-    def assert_database_health(self, status):
+    def assert_database_health(self, status, status_code=200):
         response = self.client.get('/health', follow=True)
         self.assertEquals(
             response.data,
@@ -57,7 +57,7 @@ class OperationalEndpointsTest(TestCaseWithAuthentication):
                 }
             }
         )
-        self.assertEquals(response.status_code, 200)
+        self.assertEquals(response.status_code, status_code)
 
     @staticmethod
     @contextmanager
@@ -71,7 +71,7 @@ class OperationalEndpointsTest(TestCaseWithAuthentication):
         databases['reporting'] = {}
 
         with self.override_database_connections(databases):
-            self.assert_database_health('UNAVAILABLE')
+            self.assert_database_health('UNAVAILABLE', status_code=503)
 
     # Workaround to remove a setting from django settings. It has to be used in override_settings and then deleted.
     @override_settings(ANALYTICS_DATABASE='reporting')

analyticsdataserver/views.py

@@ -69,8 +69,11 @@ class HealthView(APIView):
     permission_classes = (permissions.AllowAny,)
 
     def get(self, request, *args, **kwargs):  # pylint: disable=unused-argument
-        overall_status = 'UNAVAILABLE'
-        db_conn_status = 'UNAVAILABLE'
+        OK = 'OK'
+        UNAVAILABLE = 'UNAVAILABLE'
+
+        overall_status = UNAVAILABLE
+        db_conn_status = UNAVAILABLE
 
         try:
             connection_name = getattr(settings, 'ANALYTICS_DATABASE', 'default')
@@ -78,8 +81,9 @@ class HealthView(APIView):
             try:
                 cursor.execute("SELECT 1")
                 cursor.fetchone()
-                overall_status = 'OK'
-                db_conn_status = 'OK'
+
+                overall_status = OK
+                db_conn_status = OK
             finally:
                 cursor.close()
         except Exception:  # pylint: disable=broad-except
@@ -92,4 +96,4 @@ class HealthView(APIView):
             }
         }
 
-        return Response(response)
+        return Response(response, status=200 if overall_status == OK else 503)