This post resume for my own convenience, what to do in order to install Terraform on an Ubuntu machine.
Add HasiCorp GPG key:
curl -fsSL https://apt.releases.hashicorp.com/gpg | sudo apt-key add -Add the repository:
sudo apt-add-repository "deb [arch=amd64] https://apt.releases.hashicorp.com $(lsb_release -cs) main"Eventually, update and install the terraform package:
sudo apt-get update && sudo apt-get install terraform