Healthchecks.io is a very nice service that allows you to monitor the status of some automatic tasks (backups,…). It can also be used to check regularly that a device is still running and online (heartbeat). Healthchecks integrate with multiple services (mail, telegram, whatsapp,…) so it can send messages if some check fails.
On top of that, it can also be polled by API to check the status of the various checks implemented.
I think it would be a very nice integration witrh HA. First as a sensor: HA could poll healthcheck API in order to check the status of the different checks. A second option would be to make it so healthcheck can directly send alerts to home-assistant instead of telegram, so it could trigger actions in HA later on.
So far I am using the RESTful sensor and template sensors in order to get everything. This works quite well, but would definitely be better if integrated directly.
I’m currently working on this, and am having trouble getting the auth keys correctly configured. Would you be willing to post a sanitized version of your sensor/template config?
It is probably not that complicated to port such a simple logic to a full blown healthchecks integration that would generate the sensors properly from the API result. I just do not have time to do it now or anytime soon.
For some reason, it started to fail repeatedly to ping from HA and at some point, the entity for Home Assistant monitor (and only that one) was just not provided by the integration anymore.