Get notified when things don't happen.
$ sudo adduser --disabled-password --gecos "" watchword
$ sudo -iu watchword
# Should now be in the watchword user's home directory
$ git clone https://github.com/eallrich/watchword
$ cd watchword
# Set up secrets
echo "MAIN_DOMAIN='example.com'" > secrets
echo "PING_DOMAIN='ping.example.com'" >> secrets
echo "MAILGUN_API_KEY='key-abcdef...'" >> secrets
echo "MAILGUN_SENDER_DOMAIN='example.com'" >> secrets
echo "EXTERNAL_WATCH='hc-ping.com/a-b-c-d'" >> secrets
$ scripts/setup
$ honcho startI first learned about this concept (of alerting on non-events) from Dead Man's Snitch and subsequently saw it on Cronitor. Open source implementations exist, such as Coal Mine and healthchecks (which also comes in a hosted version).
Building my own implementation enables experimentation and provides learning opportunities. Plus, it's fun!
I've greatly benefited from the architecture and design of healthchecks in constructing watchword. Thank you, cuu508!