Arista Warrior, 2nd Edition

Chapter 27. Event Manager

Event Manager is a feature in Arista switches that allows Bash scripts to be executed when certain system events occur. When I first wrote this chapter, I used EOS version 4.9.3, and the triggers were pretty limited. This update is using EOS 4.21.1F with Arista 7280SE-72 or 7280R switches on which some cool new options are included, most of which were added in 4.17.

So, what’s the benefit of such a feature? Suppose that you have a system that’s been spontaneously rebooting at odd times, and your executive management is too cheap to buy network management software. You could configure an event handler to send email (Chapter 22) to you (or the system guys, or whomever you’d like) any time the switch’s interface to that server goes down.

Description

Event handlers allow the creation of a trigger and an action. The trigger in my server example would be the interface on the switch going up or down. The action would be the email being sent. Additionally, we can set a delay so that a configured amount of time must pass after the trigger before the action is taken.

Note

If you’re convinced that you found a mistake because the name of the chapter is Event Manager but the previous paragraph says event handler, hold your errata, because this is a bit of an Aristacism. You see, the developers made a tool and named it after what it does: it handles events. Marketing then gets a hold of it and named it something that they like better: Event Manager. That’s why Event ...