I made rails 5.2.3 to work with react-on-rails with ajaxify datatable. It was a joy!
RDS_DB_NAME: rails-examination_development
RDS_USERNAME: postgres
RDS_PASSWORD: postgres
RDS_HOSTNAME: localhost
RDS_PORT: 5432
SECRET_KEY_BASE: 'insert here' # rails credentials:edit
RAILS_ENV: development
Then
$ rails db:create
$ rails db:migrate
$ rails db:seed
Run separately
$ rails s
$ ./bin/webpack-dev-server
or with foreman
as described
// Then run server with static client side files:
$ foreman start -f Procfile.dev
// To run with the webpack-dev-server:
$ foreman start -f Procfile.dev-server