This system powers the Heroku web portion of our Outage Lights system.
Web Frontend to serve status to Arduino and people.
Check the heartbeat and sends an email when it stops.
Sinatra application that implements a heartbeat monitor.
A self-refreshing page that is all green or all red depending on if the heartbeat request came in within the interval.
Requires shared-secret over HTTPS Basic Auth.
Sets 'heartbeat' key in Redis with expiry of HEARTBEAT_DELAY
Returns request body of red or green for easy machine parsing.
We take care to not trip the lights when we fuck up.
You can simulate red by setting the FIREDRILL ENV variable.
> redis-server
> bundle exec t
GOOGLE_AUTH_DOMAIN -> google auth api domain
REDISTOGO_URL -> redis key-value store to hold and expire the heartbeat
HEARTBEAT_DELAY -> how long to wait for the next heartbeat (seconds)
MONITOR_INTERVAL -> polling interval for the monitor process (seconds)
MONITOR_EMAIL -> who to email
API_USERNAME -> HTTP Basic username for the `/status` request
API_PASSWORD -> HTTP Basic password for the `/status` request
SENDGRID_USERNAME, SENDGRID_PASSWORD -> Mail credentials
FIREDRILL -> send red from '/status'