Created an Ubuntu EC2 instance, then followed
https://gorails.com/setup/ubuntu/14.04 to install and setup ruby on rails.
Also,
https://www.digitalocean.com/community/tutorials/how-to-setup-ruby-on-rails-with-postgres
for the postgres setup:
in config/database.yml set:
production:
<<: *default
database: myrailsapp_production
username: <linux user account here, also create user with same user name in postgres db for "create role" command>
password: <db password from "create role" command>
Added a security group "custom tcp rule" to permit port 3000 inbound. Wasn't getting a response from ruby on rails after running 'rails server'.
netstat -tulpn showed it was listening on 127.0.0.1. To make listen on all ports followed https://fullstacknotes.com/make-rails-4-2-listen-to-all-interface/ , i.e. do instead:
rails server -b 0.0.0.0
should try
this later.