Sensu

Sensu

The Sensu transport will POST an Event to the Agent API upon an alert being generated.

It will be categorised (ok, warning or critical), and if you configure the alert to send recovery notifications, Sensu will also clear the alert automatically. No configuration is required - as long as you are running the Sensu Agent on your poller with the HTTP socket enabled on tcp/3031, LibreNMS will start generating Sensu events as soon as you create the transport.

Acknowledging alerts within LibreNMS is not directly supported, but an annotation (acknowledged) is set, so a mutator or silence, or even the handler could be written to look for it directly in the handler. There is also an annotation (generated-by) set, to allow you to treat LibreNMS events differently from agent events.

The 'shortname' option is a simple way to reduce the length of device names in configs. It replaces the last 3 domain components with single letters (e.g. websrv08.dc4.eu.corp.example.net gets shortened to websrv08.dc4.eu.cen).

Limitations

• Only a single namespace is supported
• Sensu will reject rules with special characters - the Transport will attempt to fix up rule names, but it's best to stick to letters, numbers and spaces
• The transport only deals in absolutes - it ignores the got worse/got better /changed states
• The agent will buffer alerts, but LibreNMS will not - if your agent is offline, alerts will be dropped
• There is no backchannel between Sensu and LibreNMS - if you make changes in Sensu to LibreNMS alerts, they'll be lost on the next event (silences will work)

Example: