Docker deployment with custom site_settings.yml

I think, perhaps, it is settings.yml, based on

unless Rails.env.test? && ENV['LOAD_PLUGINS'] != "1"
  Dir[File.join(Rails.root, "plugins", "*", "config", "settings.yml")].each do |file|
    load_settings(file)
  end
end

from discourse/app/models/site_setting.rb at main · discourse/discourse · GitHub