Initialise the Rails Application

Default Rails setup

Ensure that your asdf plugins are up to date with asdf plugin update --all.
Install the latest Ruby version with asdf install ruby latest (Check if it's supported by Heroku).
Switch your global Ruby to the fresh one: asdf global ruby latest.
Run gem update --system to update Ruby's default gems (e.g. bundler).
Check if you are using the latest stable version of Rails with rails -v and update it if you are not. You can do this with gem update rails. Beware of beta versions.
Start a new Rails project using

rails new [project-name] --database=postgresql --skip-ci --no-skip-test --skip-action-mailbox --template https://raw.githubusercontent.com/renuo/applications-setup-guide/main/ruby_on_rails/template.rb

where the project-name is exactly the one you chose before.

⚠️ You may want to choose a different database than Postgres, but most of the time this will be your choice.
If you do not need a DB you may rethink the fact that you may not need Rails at all: Take a look at Sinatra or Angular
You might also need actionmailbox of course, so always double-check the parameters that you are using.

⭐️ This setup does not include either js-bundling nor css-bundling by default.
It will start with the simplest possible Rails setup and will use sprockets and importmaps.
If you need to do fancy stuff, discuss with your team the opportunity of including a js-bundling and css-bundling tool.
We want to go "no build" whenever possible.

Run bin/setup
Run bundle exec rails db:migrate to generate an empty schema.rb file.
Then check your default Rails setup by running rails s and visiting http://localhost:3000. You should be on Rails now, yay!
Finally check if http://localhost:3000/up is green.

Adjustments

Some adjustments are made automatically by the template, but you should check them. Some other adjustments must be performed manually.

Automatic adjustments

⭐The Gemfile reads the required ruby version from the .ruby-version file. This is used by Heroku to determine what version to use. Deploio reads the ruby version from the Gemfile, with the .ruby-version file inlined into it. https://paketo.io/docs/howto/ruby/#override-the-detected-ruby-version

⭐️renuocop replaces the default rubocop-rails-omakase. We have our own set of rules at Renuo. You can discuss them at https://github.com/renuo/renuocop and you can also contribute to them.

⭐️a bin/check script is added to the project. This script will run all the tests of the project. It is used in our CI and can be used locally to check if everything is fine. You can customize it to your needs.

⭐️a bin/fastcheck script is added to the project. This script will run all the linters of the project. It is used in our CI and can be customized to your needs. It will be used as a hook before pushing to quickly check for linting issues.

⭐️a bin/run script is added to the project. This script will start the application.

⭐️bin/check, bin/fastcheck and bin/run are standardized tools for more convenience at Renuo.

Manual adjustments

Please perform these adjustments manually:

ENV variables with Figaro

Add figaro to Gemfile. Check the gem homepage to see how to install the gem (usually bundle exec figaro install is enough). Delete the newly created file config/application.yml...
and create config/application.example.yml where you will specify the only environment variable you need for now: SECRET_KEY_BASE.
Going forward we will only push the config/application.example.yml file to the repository in order to protect our env variables.
Add application.yml to .gitignore

Add the following section to your bin/setup script so that the application.yml is created from the application.example.yml when the project is setup locally:

puts "\n== Copying sample files =="
unless File.exist?('config/application.yml')
  system! 'cp config/application.example.yml config/application.yml'
end

add one more key to application.example.yml APP_PORT: 3000

Make sure it comes before any rails comands.
To ensure you have all the required keys from the application.example.yml in your application.yml, create the initializer for figaro in config/initializers/figaro.rb:
```
Figaro.require_keys(YAML.load_file('config/application.example.yml').keys - %w[test production development])
```
Run bin/setup again.

Configuration customisation

Update config/application.rb and set the default language and timezone

config.time_zone = 'Zurich' # may vary
config.i18n.default_locale = :de # may vary

Update your config/environments/production.rb settings:

config.force_ssl = true # uncomment
config.log_level = ENV.fetch("RAILS_LOG_LEVEL", "warn") # change

Update config/environments/development.rb settings:

config.action_controller.action_on_unpermitted_parameters = :raise
config.i18n.raise_on_missing_translations = true # uncomment

Update config/environments/test.rb settings:

config.action_controller.action_on_unpermitted_parameters = :raise
config.i18n.raise_on_missing_translations = true # uncomment
config.i18n.exception_handler = Proc.new { |exception| raise exception.to_exception } # add
config.active_record.verbose_query_logs = true # add

# add the following lines to the end of the file
config.to_prepare do
  ActiveSupport.on_load(:active_record) do
    ActiveRecord::ConnectionAdapters::PostgreSQLAdapter.create_unlogged_tables = true
  end
end

The default Content Security Policies should not always be activated, but rather only where there are platform secrets that need to be secured. This rule can be overwritten by a customer, if he opted into CSP when selecting his maintenance plans.

If you're using a js-bundling tool, let's clean up after asset precompilation to reduce Heroku slug size. Add this to the Rakefile:

Rake::Task['assets:clean'].enhance do
  FileUtils.remove_dir('node_modules', true)
  FileUtils.remove_dir('vendor/javascript', true)
end

Finalising

Check if the following scripts run successfully: bin/setup, bin/check, bin/run
If they do, commit all your changes to the main branch with Git.

Renuo - Application Setup Guide