Merge pull request #29 from epoch8/fix_mysql

Fix mysql

CHANGELOG.md

@@ -1,6 +1,10 @@
 # Changelog
 All notable changes to this project will be documented in this file.
 
+## 0.4.4 - 2018-11-21
+
+- Fix [#29](https://github.com/epoch8/airflow-exporter/issues/29): fix run with mysql by @cleverCat
+
 ## 0.4.3 - 2018-11-21
 
 - Fix [#23](https://github.com/epoch8/airflow-exporter/issues/23): Airflow database CPU usage by @cleverCat

prometheus_exporter.py

@@ -1,4 +1,5 @@
 from sqlalchemy import func
+from sqlalchemy import text
 
 from flask import Response
 from flask_admin import BaseView, expose
@@ -63,7 +64,12 @@ def get_dag_duration_info():
     '''get duration of currently running DagRuns
     :return dag_info
     '''
-    duration = func.sum(func.now() - DagRun.start_date)
+    driver = Session.bind.driver
+    durations = {
+        'mysqldb': func.sum(func.timestampdiff(text('second'), func.now(), DagRun.start_date)),
+        'default': func.sum(func.now() - DagRun.start_date)
+    }
+    duration = durations.get(driver, durations['default']) 
 
     with session_scope(Session) as session:
         return session.query(
@@ -111,8 +117,12 @@ def collect(self):
             'Duration of currently running dag_runs in seconds',
             labels=['dag_id', 'run_id']
         )
+        driver = Session.bind.driver
         for dag in get_dag_duration_info():
-            dag_duration.add_metric([dag.dag_id, dag.run_id], dag.duration.seconds)
+            if driver == 'mysqldb':
+                dag_duration.add_metric([dag.dag_id, dag.run_id], dag.duration)
+            else:
+                dag_duration.add_metric([dag.dag_id, dag.run_id], dag.duration.seconds)
         yield dag_duration