Category Archives: Ubuntu 14.04

Installing and migrating Ubiquity Unifi Controller software

I recently upgraded and expanded the wireless network at the office. We replaced our outdated and failing Linksys WRT54G routers with a set of Ubiquiti Unifi UAP-AC-LITE access points. The process of upgrading the network has been one of the more enjoyable tasks I have been assigned recently and the new wireless system works amazingly well.

This guide outlines installing the Unifi Controller software on an Ubuntu 14.04 server for configuring and managing the access points as well as migration from one controller to another.

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Using cron to alert to known error conditions in log file

Recently I’ve been having issues with a VirtualBox machine crashing at random. The only common thread is a line of log file, and so far, google has not been helpful in determining the root cause. This machine is important enough that I need to know when it crashes, but not important enough to actually take the time to fix properly, so I researched and created a command to toss into cron to check the log file for the error line and email me when it finds it.

The command itself is simple. Search the log file with grep, if the search generated results send an email. I tried several iterations of this before finding one that did not email when the search was empty and also did not generate silent errors when empty as well. I run this via cron at 5 minute intervals

To use this command on ubuntu 14.04 you will need to install mailutils and moreutils

Software and versions used or mentioned:
mailutils
mailx
moreutils
ifne

Resources:
Forum post with grep | mailx solution
ServerFault post with ifne solution