ntfy
ntfy: a first setup, important settings, verification, and recovery considerations.
Working directory: ~/homelab/ops/notifications. Follow the common setup workflow first. This is a setup note based on the linked documentation, not a copy of my live configuration or a runtime verification of this full stack.
Start here
ntfy delivers messages to subscribed clients. Begin with its Docker installation and a topic containing only a test message. A hard-to-guess topic name is not an access policy. Decide which account may publish and which may subscribe before connecting real alerts.
Settings and data
For a private server configure an authentication store and auth-default-access: deny-all, then grant explicit topic permissions using the documented user/access commands. Persist authentication and any required cache data. Use HTTPS for credentials and set the correct base URL.
Check it
Send a harmless message with an authorized test account and confirm receipt on the intended client. Repeat without credentials and verify denial. Restart and check that permissions remain. Test both failure and recovery notifications from a disposable monitor.
When something fails
If publishing succeeds but nothing arrives, compare topic, subscriber login, client connectivity, and notification permissions. Do not include full logs or credentials in alert text. A notification service on the failed host cannot reliably report that host's total outage; plan an independent check for that case.