Simple round-trip email monitoring
mxflow is a free mail server monitor that periodically sends email messages to a test mailbox on your server. If that message isn't delivered back within a configurable amount of time, you'll receive an alert.
mxflow runs on App Engine and can be run for free without billing enabled, when using the default settings and monitoring a single server.
- Create a new App Engine project. Note the Project ID (AKA App ID).
- Download a copy of this application.
- Adjust the settings:
- In app.yaml, set
application: <your app id> - Create a file called
config.iniand add one or more servers to monitor. Seeexample.config.inifor more info. - Optionally adjust the settings in
cron.yaml. Note that the default values are set to keep the application under the billing limits. If you increase the/probesendtask to a level where it sends more than 100 messages a day, you'll hit the free quota and the probes will stop working. Also note that alert emails count toward the quota. See the mail quota info for details.
- In app.yaml, set
- Add a mailbox on your mail server and configure it to forward mail to the receiving email for your App Engine instance. The receiving email looks like this: string@appid.appspotmail.com
- Deploy the application to App Engine. This is left as an exercise for the reader, although I'm sure that a tutorial would be welcome.
- Initial version
Pull requests for fixes and new features are welcome. This is my first useful Python application, so feel free to set me straight where necessary!
- Fix time displays to use local time zone
- Add a new cron task (and setting?) to truncate the probe history
- Add charts showing round-trip performance over time
- Save the server configuration in the datastore and allow it to be modified without re-deploying the app
- Consider a switch from cron to the task queue api for testing of failed probes