1. Install gpg2 and curl
    sudo apt-get install gnupg2 curl
    

    or

    sudo apt install gnupg2 curl
  2. Follow directions in this article https://www.digitalocean.com/community/tutorials/how-to-install-ruby-on-rails-with-rvm-on-ubuntu-18-04 but use the latest gpg2 key from https://rvm.io. These instructions still work for Ubuntu 19.10
  3. Verify you have ruby installed:
    which ruby

    If you get an error…

    /bin/bash --login
    which ruby
  4. Install yarn following these instructions https://classic.yarnpkg.com/en/docs/install/#debian-stable
  5. Then install webpacker
    rails webpacker:install