Asciinema is the perfect tool to share terminal sessions and it is one that we regularly use at Bitsoko to share a terminal workflow or record terminal behaviour.
You can find the asciinema website here.
Asciinema package is available in the Ubuntu repository in Ubuntu 16.04. It may not be bleeding edge as with any repository package but it works well out of the box.
To install asciinema on Ubuntu using the Ubuntu repos, run the following:
sudo apt update
sudo apt upgrade
sudo apt install asciinema
To start a record session:
To exit from a record session:
A sample record session of mine can be found here.