Letsencrypt asks for root password? Where to find good client documentaion?

while webroot method doesn't touch existing web server, the software dependencies for the letsencrypt client DO require root access to install i.e. yum or apt packages like python etc

indeed i agree, although never came across this with letsencrypt as I always ran as root user in the first place as I knew those software dependencies and web server do require root access to play with.

i use letsencrypt via webroot authentication plugin Letsencrypt Webroot Authentication Tested on Beta invited/whitelisted domain and Using the webroot domain verification method

my current LE integration progress https://community.centminmod.com/posts/20305/