Sidekiq Monit

15 Jun 2017

起因：

预防大量用户注册时卡顿，Devise发送账号确认信这个动作必须异步完成。用devise还是比较繁重的，有坑还是需要记录一下。

1.安装gem & 引用模块。

原版gem已经不支持devise4以上的版本了，这里要更改github地址并修改抓取的branch。
gem "devise-async", :git => "git@github.com:swapnilchincholkar/devise-async.git", :branch => "devise-4.x"
bundle后,修改user.rb

   class User < ActiveRecord::Base
    devise :database_authenticatable, :confirmable, :async # etc ...
   end

2.让DeviseAsync使用Sidekiq。

添加文件并设定:

# config/initializers/devise_async.rb
Devise::Async.enabled = true
Devise::Async.backend = :sidekiq
Devise::Async.queue = :default

3.添加覆盖devise原生发信方式的类。

# lib/devise_backgrounder.rb

# Mailer proxy to send devise emails in the background
class DeviseBackgrounder

  def self.confirmation_instructions(record, opts = {})
    new(:confirmation_instructions, record, opts)
  end

  def self.reset_password_instructions(record, opts = {})
    new(:reset_password_instructions, record, opts)
  end

  def self.unlock_instructions(record, opts = {})
    new(:unlock_instructions, record, opts)
  end
  
  def initialize(method, record, opts = {})
    @method, @record, @opts = method, record, opts
  end
  
  def deliver
    # You need to hardcode the class of the Devise mailer that you
    # actually want to use. The default is Devise::Mailer.
    Devise::Mailer.delay.send(@method, @record, @opts)
  end

end

这里原教程的最后一个方法名称为deliver_later，这样会导致发信失败抛出NoMethod Name "deliver",这里要修改方法名为deliver。

4.修改部分设定。

修改devise邮件默认类。

# config/initializers/devise.rb
Devise.setup do |config|
# ...stuff here
config.mailer = "DeviseBackgrounder"
# ...more stuff here
end

让系统自动加载自定义类。

# config/application.rb
# ..
config.autoload_paths += %W(#{config.root}/lib)
# ..

添加sidekiq.yml于config ``` :queues:
- default
- [mailers, 2] ```