```ruby
namespace :applications do

  desc "Creates an application(OAuth client)"
  task :create => :environment do
    # Create client app
    a = Doorkeeper::Application.create!(
      name: ENV['name'],
      redirect_uri: ENV['redirect_uri'],
      description: ENV['description'],
      home_uri: ENV['home_uri']
    )
    # Optionally set up supported permissions
    permissions = (ENV['supported_permissions'] || '').split(',')
    permissions.each do |permission|
      SupportedPermission.create(:application_id => a.id, :name => permission)
    end
    # Done
    puts "Application '#{a.name}' created."
    puts
    puts "config.oauth_id     = '#{a.uid}'"
    puts "config.oauth_secret = '#{a.secret}'"
  end
end
```

Add rake task to migrate apps to new domain.
user
```ruby
namespace :applications do

  desc "Creates an application(OAuth client)"
  task :create => :environment do
    # Create client app
    a = Doorkeeper::Application.create!(
      name: ENV['name'],
      redirect_uri: ENV['redirect_uri'],
      description: ENV['description'],
      home_uri: ENV['home_uri']
    )
    # Optionally set up supported permissions
    permissions = (ENV['supported_permissions'] || '').split(',')
    permissions.each do |permission|
      SupportedPermission.create(:application_id => a.id, :name => permission)
    end
    # Done
    puts "Application '#{a.name}' created."
    puts
    puts "config.oauth_id     = '#{a.uid}'"
    puts "config.oauth_secret = '#{a.secret}'"
  end

  desc 'Updates domain name for applications'
  task :migrate_domain => :environment do
    raise "Requires OLD_DOMAIN + NEW_DOMAIN specified in environment" unless ENV['OLD_DOMAIN'] && ENV['NEW_DOMAIN']
    Doorkeeper::Application.find_each do |application|
      [:redirect_uri, :home_uri].each do |field|
        new_domain = application[field].gsub(ENV['OLD_DOMAIN'], ENV['NEW_DOMAIN'])
        if application[field] != new_domain
          puts "Migrating #{application.name} - #{field} to new domain: #{new_domain}"
          application[field] = new_domain
        end
      end
      application.save!
    end
  end
end
```
assistant