If you do a search of the My Cloud subforum you’ll find several threads discussing how to install/run a webserver on the My Cloud. Note that the single bay My Cloud units are not really designed to host a full fledged website. Note: Many if not most of the links below deal with the v3.x/v4.x firmware My Cloud. My Cloud’s running v2.x firmware is different and the directions below may not work with v2.x firmware.
http://community.wd.com/t/app-webhosting-for-firmware-v4-10-2015/94892
