Add simple Good-to-Go healthcheck

Only check the flask app and the mongo database is available

alerta/app/database/mongo.py

@@ -49,7 +49,7 @@ def connect(self):
         mongo_uri = mongo_uri or app.config['MONGO_URI']  # use app config if no env var overrides
 
         try:
-            self.connection = MongoClient(mongo_uri, connect=False)
+            self.connection = MongoClient(mongo_uri, serverSelectionTimeoutMS=2000, connect=False)
         except Exception as e:
             LOG.error('MongoDB Client: %s : %s', mongo_uri, e)
             sys.exit(1)
@@ -80,6 +80,15 @@ def get_version(self):
 
         return self.db.client.server_info()['version']
 
+    def is_alive(self):
+
+        from pymongo.errors import ConnectionFailure
+        try:
+            self.db.client.admin.command('ismaster')
+        except ConnectionFailure:
+            return False
+        return True
+
     def disconnect(self):
 
         self.connection.close()

alerta/app/management/views.py

@@ -98,6 +98,16 @@ def switchboard():
             return render_template('management/switchboard.html', switches=switches)
 
 
+@app.route('/management/gtg', methods=['OPTIONS', 'GET'])
+@cross_origin()
+def good_to_go():
+
+    if db.is_alive():
+        return 'OK'
+    else:
+        return 'FAILED', 503
+
+
 @app.route('/management/healthcheck', methods=['OPTIONS', 'GET'])
 @cross_origin()
 def health_check():