How to run Jekyll on Ubuntu Linux

Install prerequisites https://jekyllrb.com/docs/installation/ubuntu/

sudo apt-get install ruby-full build-essential zlib1g-dev
echo '# Install Ruby Gems to ~/gems' >> ~/.bashrc
echo 'export GEM_HOME="$HOME/gems"' >> ~/.bashrc
echo 'export PATH="$HOME/gems/bin:$PATH"' >> ~/.bashrc
source ~/.bashrc
gem install jekyll bundler

Quickstart instructions to set up a site https://jekyllrb.com/docs/

cd into web root directory

cd root

Run jekyll serve to test the site locally

jekyll serve

If there is an error you may need to install webrick bundle add webrick