Deploy a Ruby on Rails 3 application to free hosting

Since Ruby on Rails 3 was released, I have had problems with deployment configuration, such as asset precompilation. Of course, if you deploy an application to a powerful host, you won’t have any problems, and deployment to such a host will be standard and simple. But if you have a server with little RAM (less than 1 GB), you will have to wait a long time for assets to be precompiled. So here I will explain how to avoid precompiling assets on the server and decrease deployment time.

1. Free hosting

If you don’t already know about free Ruby hosting, I would recommend heroku. It’s a beautiful free hosting service that lets you deploy Rack/Ruby on Rails applications.

I won’t describe how it works here because you can find a lot of information about it on the official site.

I have been using a free account for months for the blog you are reading now, and I haven’t had any issues with server failures, long loading times or anything like that. Sometimes there were about 1000 visitors per hour, and everything worked. So I think a free account will be enough for your new services or staging/QA environments. If you don’t have enough memory, you can buy a web dyno for $36 per month. You can also install add-ons — a wonderful heroku feature that saves you time installing and configuring additional services required by your application, such as:

• Free email services
• Scheduling
• Databases
• Search engines
• and so on.

NOTE: there are restrictions for every add-on.

I hope you have already signed up and are ready for the next step.

2. Assets bucket

There are several ways to precompile assets and connect them to a Rails 3 application:

1. You can precompile assets on your local machine and make a commit. But I think it is a bad idea because you will have large commits whenever any JS/CSS changes.
2. Precompile assets during deployment on the server. This requires an instance with at least 1 GB of memory and write access to the assets directory.
3. Add the assets directory to the ignore list for your VCS (Version Control System), precompile the assets and upload them to an assets bucket. An assets bucket is a server that lets you store static data and retrieve it through a public URL.

I prefer the 3rd option because heroku doesn’t allow you to save files on the instance. Also, 1 free web dyno has only 512 MB of memory. To save assets in the bucket, we should choose a server with an API for our needs. There are a lot of services on the internet: AWS S3, Dropbox, Rackspace Cloud Files and so on. It would be simple to use Dropbox for our problem: once you have precompiled assets, just copy them to the Dropbox public folder, tell your application where to look for assets, and that’s it! But I prefer to use S3 because I calculated that it will be cheaper for me in the future.

3. Amazon S3

• Go to AWS and sign up there. A credit card with a positive balance is required.
• Go to the AWS console, choose the S3 tab and create a bucket.

NOTE: There are several regions where you can store your bucket. Choose the nearest one to your future visitors for a better server response time.

• Go to CloudFront tab and create distribution for your bucket

Please wait for the status to change to Deployed and the state to Enabled. It will take a few minutes (usually 5–10 minutes).

4. Deployment

To upload assets to the bucket, I use the jammit-s3 gem. It is simple to configure and use.

• Add this line to your Gemfile: gem ‘jammit-s3’, :group => :development
• Install the new gem by typing the command bundle in the terminal.
• Go to the AWS security credentials page, get your Access Key Id and Secret Access Key, and create the shell variables AWS_KEY and AWS_SECRET (steps 4–5).
• **export AWS_KEY=YOUR_ACEESS_KEY_ID **
• export AWS_SECRET=YOUR_SECRET_ACCESS_KEY
• Create the file config/assets.yml with this content:

s3_bucket: YOUR_BUCKET_HERE
s3_access_key_id: <%= ENV['AWS_KEY'] %>
s3_secret_access_key: <%= ENV['AWS_SECRET'] %>
s3_upload_files:
  -  public/assets/**/*

• Edit your config/environments/production.rb file:

MyApplication::Application.configure do
  # Code is not reloaded between requests
  config.cache_classes = true
  # Full error reports are disabled and caching is turned on
  config.consider_all_requests_local       = false
  config.action_controller.perform_caching = true
  	# Disable Rails's static asset server (Apache or nginx will already do this)
  config.serve_static_assets = false
  # Compress JavaScripts and CSS
  config.assets.compress = true
  # Don't fallback to assets pipeline if a precompiled asset is missed
  config.assets.compile = false
  # Generate digests for assets URLs
  config.assets.digest = true
  # Specifies the header that your server uses for sending files
  # config.action_dispatch.x_sendfile_header = "X-Sendfile" # for apache
  config.action_dispatch.x_sendfile_header = 'X-Accel-Redirect' # for nginx
  # Enable serving of images, stylesheets, and JavaScripts from an asset server
  config.action_controller.asset_host = "http://YOUR_BUCKET_NAME.s3.amazonaws.com"
  # Enable locale fallbacks for I18n (makes lookups for any locale fall back to
  # the I18n.default_locale when a translation can not be found)
  config.i18n.fallbacks = true
  # Send deprecation notices to registered listeners
  config.active_support.deprecation = :notify
end

Pay attention to config.action_controller.asset_host: it should be your bucket URL!

• Add public/assets to .gitignore:

  /public/assets

In production mode, the manifest.yml file is required. It is generated in the /public/assets folder when assets are precompiled. I see a nice solution in changing the path for the manifest.yml file. Go to config/environments/production.rb and edit it like this:

# ...
# Defaults to Rails.root.join("public/assets")
config.assets.manifest = 'public/manifest'
# ...

We are ready to deploy the application. Let’s precompile the assets:

RAILS_ENV=production rake assets:precompile --trace

Uploading assets to S3 is very simple:

bundle exec jammit-s3

Create a heroku application:

heroku create

Make a commit and push it to heroku:

git commit -am 'assets precompiled'
git push heroku master

The default DB for a heroku application is postgresql. If you would like to change it, install your preferred add-on.

Of course, you should run migrations if your application has any:

heroku run rake db:migrate
heroku run rake db:seed # if you have required seeds

I hope this post will be useful not only for me. Thanks for reading!