Sending ntfy Alerts

Emails are easy to use as alerts, but they're not real-time like a push notification. An interesting real-time alerting method is ntfy, which I described in a previous article [5]. Assuming you've set up a ntfy server as described in that article, you just need to create a user and token for Gatus. To do this, open a shell within ntfy's Docker container:

$ docker exec -ti ntfy /bin/sh

Next, create a user for Gatus and grant it write permissions on the topic gatus:

/ # ntfy user add gatus
user gatus added with role user
/ # ntfy access gatus gatus write-only
granted write-only access to topic gatus
user gatus (role: user, tier: none)
- write-only access to topic gatus

The first command asks you to set up a password for the user. However, Gatus doesn't support authenticating to ntfy with a password, so you need to generate a token for the user:

/ # ntfy token add gatus
token tk_7yp9hmwwwoxlag9xaz5clmi5n43qw created for user gatus, never expires

Then you configure ntfy alerting in Gatus' configuration file, as shown in Listing 11. For each endpoint that will use these ntfy alerts, include the following:

alerts:
      - type: ntfy

01 alerting:
02   ntfy:
03     url: https://ntfy.example.com
04     topic: gatus
05     token: tk_7yp9hmwwwoxlag9xaz5clmi5n43qw
06     click: https://gatus.example.com
07     disable-firebase: true

Now add a subscription to the topic in ntfy's mobile app [6] and make sure your user has read access to the topic. You'll be alerted in real time on your phone for any outage now.

Conclusion

Gatus is straightforward to set up, yet powerful, offering many types of health checks and alert types. If you don't like using a YAML file for configuration, there are alternative status dashboards that offer web-based configuration, such as Uptime Kuma [7]. However, because Gatus' full configuration resides in one YAML file, it is easy to automatically generate the configuration with a script based on your systems, making Gatus even more flexible than it already is on its own.

The Author

Koen Vervloesem has been writing about Linux and open source, computer security, privacy, programming, artificial intelligence, and the Internet of Things for more than 25 years. He holds master's degrees in computer science engineering and philosophy and is teaching Linux, Python, and IoT classes. You can find more on his website at http://koen.vervloesem.eu.