Add healthcheck endpoint (#1012)

* Add healthcheck endpoint

* Add unittest for healthcheck route

* Pin vin library version

flower/urls.py

@@ -68,6 +68,7 @@
     (r"/api/task/events/task-custom/(.*)", events.TaskCustom),
     # Metrics
     (r"/metrics", monitor.Metrics),
+    (r"/healthcheck", monitor.Healthcheck),
     # Static
     (r"/static/(.*)", StaticFileHandler,
      {"path": settings['static_path']}),

flower/views/monitor.py

@@ -11,3 +11,9 @@ class Metrics(BaseHandler):
     @gen.coroutine
     def get(self):
         self.write(prometheus_client.generate_latest())
+
+
+class Healthcheck(BaseHandler):
+    @gen.coroutine
+    def get(self):
+        self.write("OK")

requirements/default.txt

@@ -1,5 +1,6 @@
 celery>=3.1.0; python_version<"3.7"
 celery>=4.3.0; python_version>="3.7"
+vine==1.3.0
 tornado>=5.0.0,<7.0.0; python_version>="3.5.2"
 prometheus_client==0.8.0
 humanize

tests/unit/views/test_monitor.py

@@ -32,3 +32,16 @@ def test_metrics(self):
         self.assertTrue('task-received' in events)
         self.assertTrue('task-started' in events)
         self.assertTrue('task-succeeded' in events)
+
+
+class HealthcheckTests(AsyncHTTPTestCase):
+    def setUp(self):
+        self.app = super(HealthcheckTests, self).get_app()
+        super(HealthcheckTests, self).setUp()
+
+    def get_app(self):
+        return self.app
+
+    def test_healthcheck_route(self):
+        response = self.get('/healthcheck').body.decode('utf-8')
+        self.assertEquals(response, 'OK')