1. I, [2018-01-23T12:37:23.427322 #13] INFO -- : > /usr/local/bin/ruby -e 'if ENV["DISCOURSE_SMTP_ADDRESS"] == "smtp.example.com"; puts "Aborting! Mail is not configured!"; exit 1; end'
2. I, [2018-01-23T12:37:23.533130 #13] INFO -- :
3. I, [2018-01-23T12:37:23.534031 #13] INFO -- : > /usr/local/bin/ruby -e 'if ENV["DISCOURSE_HOSTNAME"] == "discourse.example.com"; puts "Aborting! Domain is not configured!"; exit 1; end'
Looks like that would be your issue - you have nothing in your /containers/app.yml file