Implementing Resque/Redis on Rails 3

Hi coders! I have a new experience here with Rails 3 and I want to share it.

I have task to create a code running on background with Rails 3 and I found that I need to use Resque/Redis to make it happen. Okay, first you need to download Redis from its origin site at http://redis.io/download. Just follow the instruction there and you will be fine.

This is the main part of this post. But actually, I also followed some instruction from a blog. You can visit it directly to http://tommy.chheng.com/index.php/2010/10/how-to-run-background-processes-using-resqueredis-in-a-ruby-on-rails-app/. Honestly, it was a bliss. These are my steps on doing it:

1. Add resque to Gemfile
   gem "resque"
2. Run bundle install
3. Create redis.yml in config folder :

   defaults: &defaults
     host: localhost
     port: 6379
   
   development:
     <<: *defaultstest:
     <<: *defaults 
   
   staging:
     <<: *defaults
   
   production:
     <<: *defaults

   You have to put “space” character for the configuration of every environment, or else you’ll get some errors.

4. Create resque.rb in config/initializers :

   Dir[File.join(Rails.root, 'app', 'jobs', '*.rb')].each { |file| require file }
   config = YAML::load(File.open("#{Rails.root}/config/redis.yml"))[Rails.env]
   Resque.redis = Redis.new(:host => config['host'], :port => config['port'])

5. Add resque.rake to lib/tasks :

   require 'resque/tasks'
   task "resque:setup" => :environment

6. Start redis server by running ./src/redis-server from root folder of redis, that you’ve downloaded and configured
7. Start resque by running COUNT=5 QUEUE=* rake resque:workers command
8. Start resque web UI by running resque-web command
9. Add your job code to resque. In my case, I added a secure copy task to another server. So what I did was creating a file called send_file.rb in models folder. The content of the file is :

   require 'net/scp'
   
   class SendFile
     @queue = :file_send #this class variable will be used as queue name in resque, so you can fill in different name
     def self.perform() # I didn't need any parameter, so I leave it blank
       Net::SCP.start('hostname.com', 'username', :password => 'password') do |scp|
         scp.upload!('local/directory', 'destination/path', {:recursive => true})
       end
     end
   end

   In my controller, I call that class by running this code
   Resque.enqueue(SendFile)


That’s it! I tried it and I succeeded. When your job is running, you can see it in resque web UI. So, why don’t you try it?
Enjoy!