[RUBY] [Rails] Implement rake task

What is a rake task?

This function executes the processing described in the file from the command line. It is used for various purposes such as changing the status according to the user's attributes, importing CSV data, sending an email to the user at any time, and so on.

Basic usage

Generate task file

$ rails g task qiita_task

Describe the process you want to execute

namespace :qiita_task do
  desc 'hello world'
  task :hw do
    puts 'Hello World'
  end
end

Run

$ rake qiita_task:hw

Other

When the process to connect to DB is included in the task

When connecting to DB, write ʻenvironment` as follows

namespace :qiita_task do
  desc 'Send an email to recently registered users'
  task send_email_to_recent_users: :environment do
    recent_users = User.where('updated_at <= ?', Time.zone.parse('2020/09/08 15:50:00'))
    recent_users.each do |ru|
      ru.send_email
    end
  end   
end

Run in production

Execute with RAILS_ENV = production in the root directory of the project (where there is Gemfile etc.).

$ rake qiita_task:hw RAILS_ENV=production

Display task list

The tasks defined by default and the tasks you created are displayed in a row.

$ rake -T

reference

-Creating a Rake task in Rails-Qiita