This article is part of a new mini-series here on my blog as I work toward obtaining my Cisco Wireless 640-722 CCNA certification.
The official way Cisco wants you to do this is to buy and implement Cisco Prime.
One way you can get around this is to use SolarWinds CatTools to send commands to your devices.
Using this I configured a job to connect to the WLC via SSH and push a backup of the config to my TFTP server. Here's how:
>transfer upload mode tftp
>transfer upload datatype config
>transfer upload filename WLC-Config-Backup_%DateISO%.txt
>transfer upload path .
>transfer upload serverip 192.168.1.5
>transfer upload start
Once you select "Y" to begin the backup you'll see in the text a warning that file encryption is disabled. Solarwinds CatTools can answer this Y or Yes if needed. After this the config will push to your TFTP directory.
The variable in the command %DateISO% will automaticaly fill out the date of the file for you. As of now the freeware version is limited to 5 devices and 5 activities only.
If you need more it can scale up from there.