Rails rake task for creating a mysql user and password

mysql_create.rake

namespace :db do

  task 'mysql:create' do

    puts '== Database Configuration =='

    app_name = Rails.application.class.parent_name.underscore
    database_name = ENV['database'] || "#{app_name}_db_#{Rails.env}"
    database_user_name = ENV['database_user'] || "#{app_name}_user_#{Rails.env}"
    database_user_password = ENV['database_password'] || ''

    puts "   Database: #{database_name}"
    puts "   User: #{database_user_name}"
    puts "   Password: #{database_user_password}"

    puts '== Creating SQL script =='

    Tempfile.open %w(mysql_config .sql) do |f|
      
      f.print <<-SQL
        CREATE USER '#{database_user_name}'@'localhost' IDENTIFIED BY '#{database_user_password}';
        GRANT ALL PRIVILEGES ON #{database_name}.* TO '#{database_user_name}'@'localhost';
        FLUSH PRIVILEGES;
      SQL
      
      f.flush

      puts '== Running SQL script =='
      cmd = "mysql -u root -p < #{f.path}"
      system(cmd) || abort("\n== Command #{cmd} failed ==")

    end

  end

end