Update app.py

app.py

@@ -68,7 +68,7 @@ credentials = auth()
 # Get instance info
 instance_info = get_server(credentials, instance_name)
 status = instance_info['status']
-ip_address = instance_info['networkInterfaces'][0]['accessConfigs'][0]['natIP']
+ip_address = instance_info['networkInterfaces'][0]['accessConfigs'][0]['natIP'] if status == 'RUNNING' else None
 max_run_duration = instance_info['scheduling']['maxRunDuration']['seconds']
 last_start_timestamp = instance_info['lastStartTimestamp']
 max_remaining_time = get_time_remaining(last_start_timestamp, max_run_duration)