Object Storage Service:Rails application (Ruby SDK)

Preparations

To use the OSS SDK for Ruby in a Rails application, add the following dependency to the Gemfile file.

gem 'aliyun-sdk', '~> 0.3.0
            

Add the following dependency when you use OSS SDK for Ruby:

require 'aliyun/oss'
            

Integration with Rails

You can perform the following steps to integrate OSS SDK for Ruby with Rails:

1. Create a project.

   1. Install Rails and create a Rails application named oss-manager.

      gem install rails
      rails new oss-manager
                                  

      Note

      In this example, the oss-manager application is a management tool for OSS objects. It can list all buckets, list objects in a bucket by directory, upload objects, and download objects.

   2. Use git to manage the project code.

      cd oss-manager
      git init
      git add .
      git commit -m "init project"
                                  

2. Add the SDK dependency.

   1. Edit oss-manager/Gemfile to add the SDK dependency.

      gem 'aliyun-sdk', '~> 0.3.0'
                                  

   2. In the oss-manager/ directory, run bundle install.

   3. Save the changes.

      git add .
      git commit -m "add aliyun-sdk dependency"
                                  

Initialize an OSSClient instance

To avoid initialization each time you use an OSSClient instance in the project, we recommend that you create an initialization file in the project.

# oss-manager/config/initializers/aliyun_oss_init.rb
require 'aliyun/oss'

module OSS
  def self.client
    unless @client
      Aliyun::Common::Logging.set_log_file('./log/oss_sdk.log')

      @client = Aliyun::OSS::Client.new(
        endpoint:
          Rails.application.secrets.aliyun_oss['endpoint'],
        access_key_id:
          Rails.application.secrets.aliyun_oss['access_key_id'],
        access_key_secret:
          Rails.application.secrets.aliyun_oss['access_key_secret']
      )
    end

    @client
  end
end            

The preceding code is stored in the rails/ directory of the installation path of OSS SDK for Ruby. You can use the OSSClient instance in the project after initialization.

buckets = OSS.client.list_buckets            

The endpoint, access_key_id, and access_key_secret values are saved in the oss-manager/conf/secrets.yml file.

development:
  secret_key_base: xxxx
  aliyun_oss:
    endpoint: xxxx
    access_key_id: aaaa
    access_key_secret: bbbb           

Save the changes.

git add .
git commit -m "add aliyun-sdk initializer"            

List all buckets

You can perform the following steps to list all buckets:

1. Use Rails to generate the controller to manage buckets.

   rails g controller buckets index
                       

2. The following files are generated in the oss-manager folder.

   • app/controller/buckets_controller.rb: contains the logical code related to buckets.

   • app/views/buckets/index.html.erb: contains the code used to display the content related to buckets.

   • app/helpers/buckets_helper.rb: defines the auxiliary functions.

3. Edit `buckets_controller.rb`. Call the OSS client and save the result of the list_buckets operation to the @buckets variable.

   class BucketsController < ApplicationController
     def index
       @buckets = OSS.client.list_buckets
     end
   end

4. Modify the views/buckets/index.html.erb file to list the buckets.

   <h1>Buckets</h1>
   <table class="table table-striped">
     <tr>
       <th>Name</th>
       <th>Location</th>
       <th>CreationTime</th>
     </tr>
   
     <% @buckets.each do |bucket| %>
     <tr>
       <td><%= link_to bucket.name, bucket_objects_path(bucket.name) %></td>
       <td><%= bucket.location %></td>
       <td><%= bucket.creation_time.localtime.to_s %></td>
     </tr>
     <% end %>
   </table>
                       

5. In `app/helpers/buckets_helper.rb`, define the bucket_objects_path helper function.

   module BucketsHelper
     def bucket_objects_path(bucket_name)
       "/buckets/#{bucket_name}/objects"
     end
   end
                       

   After you complete the preceding steps, you can list all buckets.

   You also need to configure Rails routing so that the address entered in the browser calls the correct logic. Edit config/routes.rb and add the following content.

   resources :buckets do
     resources :objects
   end
                       

   In the oss-manager/ directory, run rails s to start the Rails server. Then, navigate to http://localhost:3000/buckets/ in your browser to view the bucket list.

6. Save the changes.

   git add .
   git commit -m "add list buckets feature"
                       

List all objects in a bucket by directory

You can perform the following steps to list all objects in a bucket by directory:

1. Generate a controller to manage objects.

   rails g controller objects index
                       

2. Modify the app/controllers/objects_controller.rb file.

   class ObjectsController < ApplicationController
     def index
       @bucket_name = params[:bucket_id]
       @prefix = params[:prefix]
       @bucket = OSS.client.get_bucket(@bucket_name)
       @objects = @bucket.list_objects(:prefix => @prefix, :delimiter => '/')
     end
   end
                       

   You can obtain the bucket name from the parameters in the URL. Add a prefix to list objects by directory and call the list_object operation of the OSSClient instance to obtain the object list.

   Note

   In this example, objects whose names contain the specified prefix and a forward slash (/) as a delimiter are obtained. For more information, see Overview.

3. Modify the app/views/objects/index.html.erb file.

   <h1>Objects in <%= @bucket_name %></h1>
   <p> <%= link_to 'Upload file', new_object_path(@bucket_name, @prefix) %></p>
   <table class="table table-striped">
     <tr>
       <th>Key</th>
       <th>Type</th>
       <th>Size</th>
       <th>LastModified</th>
     </tr>
   
     <tr>
       <td><%= link_to '../', with_prefix(upper_dir(@prefix)) %></td>
       <td>Directory</td>
       <td>N/A</td>
       <td>N/A</td>
     </tr>
   
     <% @objects.each do |object| %>
     <tr>
       <% if object.is_a?(Aliyun::OSS::Object) %>
       <td><%= link_to remove_prefix(object.key, @prefix),
               @bucket.object_url(object.key) %></td>
       <td><%= object.type %></td>
       <td><%= number_to_human_size(object.size) %></td>
       <td><%= object.last_modified.localtime.to_s %></td>
       <% else  %>
       <td><%= link_to remove_prefix(object, @prefix), with_prefix(object) %></td>
       <td>Directory</td>
       <td>N/A</td>
       <td>N/A</td>
       <% end  %>
     </tr>
     <% end %>
   </table>
                       

   Objects are listed by directory based on the following logic:

   1. '../' always refers to the parent directory.

   2. Common prefixes are listed as directories.

   3. Objects are displayed as files.

   The preceding code uses helper functions such as with_prefix and remove_prefix. These helper functions are defined in `app/helpers/objects_helper.rb`.

   module ObjectsHelper
     def with_prefix(prefix)
       "?prefix=#{prefix}"
     end
   
     def remove_prefix(key, prefix)
       key.sub(/^#{prefix}/, '')
     end
   
     def upper_dir(dir)
       dir.sub(/[^\/]+\/$/, '') if dir
     end
   
     def new_object_path(bucket_name, prefix = nil)
       "/buckets/#{bucket_name}/objects/new/#{with_prefix(prefix)}"
     end
   
     def objects_path(bucket_name, prefix = nil)
       "/buckets/#{bucket_name}/objects/#{with_prefix(prefix)}"
     end
   end
                       

4. When you are finished, run rails s. Then, navigate to http://localhost:3000/buckets/my-bucket/objects/ in your browser to view the file list.

5. Save the changes.

   git add .
   git commit -m "add list objects feature"                    

Download objects

<td><%= link_to remove_prefix(object.key, @prefix),
        @bucket.object_url(object.key) %></td>               

Upload objects

Add styles

For the complete demo code, visit OSS Rails Demo.