Fog::Dtdream

Installation

Add this line to your application's Gemfile:

gem 'fog-dtdream'

And then execute:

    $ bundle

Or install it yourself as:

    $ gem install fog-dtdream

Usage

Before you can use fog-dtdream, you must require it in your application:

require 'fog/dtdream'

Since it's a bad practice to have your credentials in source code, you should load them from default fog configuration file: ~/.fog. This file could look like this:

default:
  :aliyun_accesskey_id:     <YOUR_ACCESS_KEY_ID>,
  :aliyun_accesskey_secret: <YOUR_SECRET_ACCESS_KEY>,
  :aliyun_oss_endpoint:     <YOUR_OSS_ENDPOINT>,
  :aliyun_oss_location:     <YOUR_OSS_LOACTION>,
  :aliyun_oss_bucket:       <YOUR_OSS_BUCKET>

Connecting to OSS

conn = Fog::Storage[:dtdream]

If you haven't modified your default fog configuration file or you don't want to use it, you can load your credentials by this way:

opt = {
  :provider                => 'dtdream',
  :aliyun_accesskey_id     => <YOUR_ACCESS_KEY_ID>,
  :aliyun_accesskey_secret => <YOUR_SECRET_ACCESS_KEY>,
  :aliyun_oss_endpoint     => <YOUR_OSS_ENDPOINT>,
  :aliyun_oss_location     => <YOUR_OSS_LOACTION>,
  :aliyun_oss_bucket       => <YOUR_OSS_BUCKET>,
}
conn = Fog::Storage.new(opt)

Fog::Dtdream Abstractions

Fog::Dtdream provides both a model and request abstraction. The request abstraction provides the most efficient interface and the model abstraction wraps the request abstraction to provide a convenient ActiveModel like interface.

Request Layer

The Fog::Storage object supports a number of methods that wrap individual HTTP requests to the OSS API.

To see a list of requests supported by the storage service:

conn.requests

This returns:

[[nil, :copy_object], [nil, :delete_bucket], [nil, :delete_object], [nil, :get_bucket], [nil, :get_object], [nil, :get_object_http_url], [nil, :get_object_https_url], [nil, :head_object], [nil, :put_bucket], [nil, :put_object], [nil, :list_buckets], [nil, :list_objects], [nil, :get_containers], [nil, :get_container], [nil, :delete_container], [nil, :put_container]]

Example Requests(list_buckets)

To request all of buckets:

conn.list_buckets

And this returns like the flowing;

[{"Location"=>"oss-cn-beijing", "Name"=>"dt1", "CreationDate"=>"2015-07-30T08:38:02.000Z"},  {"Location"=>"oss-cn-shenzhen", "Name"=>"ruby1", "CreationDate"=>"2015-07-30T02:22:34.000Z"}, {"Location"=>"oss-cn-qingdao", "Name"=>"yuanhang123", "CreationDate"=>"2015-05-18T03:06:31.000Z"}]

You can also request in this way;

conn.list_buckets(:prefix=>"pre")

Here is a summary of the optional parameters:

Parameters	Description
:prefix	The bucket name of the results must start with 'prefix'.It won't filter prefix information if not set Data Types: String Defaults:none
:marker	The result will start from the marker alphabetically.It wil start from the first if not set. Data Types: String Defaults: none
:maxKeys	Set the max number of the results. It will set to 100 if not set. The max value of maxKeys is 1000. Data Types: String Defaults: 100

To learn more about Fog::Dtdream request methods, you can refer to our source code. To learn more about OSS API, refer to AliYun OSS API.

Model Layer

Fog models behave in a manner similar to ActiveModel. Models will generally respond to create, save, destroy, reload and attributes methods. Additionally, fog will automatically create attribute accessors.

Here is a summary of common model methods:

Method	Description
create	Accepts hash of attributes and creates object. Note: creation is a non-blocking call and you will be required to wait for a valid state before using resulting object.
save	Saves object. Note: not all objects support updating object.
destroy	Destroys object. Note: this is a non-blocking call and object deletion might not be instantaneous.
reload	Updates object with latest state from service.
attributes	Returns a hash containing the list of model attributes and values.
identity	Returns the identity of the object. Note: This might not always be equal to object.id.

The remainder of this document details the model abstraction.

Note: Fog sometimes refers to OSS containers as directories.

List Directories

To retrieve a list of directories:

dirs = conn.directories

This returns a collection of Fog::Storage::Dtdream::Directory models:

Get Directory

To retrieve a specific directory:

dir = dirs.get "dir"

This returns a Fog::Storage::Dtdream::Directory instance:

Create Directory

To create a directory:

dirs.create :key => 'backups'

Delete Directory

To delete a directory:

directory.destroy

Note: Directory must be empty before it can be deleted.

Directory URL

To get a directory's URL:

directory.public_url

List Files

To list files in a directory:

directory.files

Note: File contents is not downloaded until body attribute is called.

Upload Files

To upload a file into a directory:

file = directory.files.create :key => 'space.jpg', :body => File.open "space.jpg"

Note: For files larger than 5 GB please refer to the Upload Large Files section.

Upload Large Files

OSS requires files larger than 5 GB (the OSS default limit) to be uploaded into segments along with an accompanying manifest file. All of the segments must be uploaded to the same container.

Segmented files are downloaded like ordinary files. See Download Files section for more information.

Download Files

The most efficient way to download files from a private or public directory is as follows:

File.open('downloaded-file.jpg', 'w') do | f |
  directory.files.get("my_big_file.jpg") do | data, remaining, content_length |
    f.syswrite data
  end
end

This will download and save the file.

Note: The body attribute of file will be empty if a file has been downloaded using this method.

If a file object has already been loaded into memory, you can save it as follows:

File.open('germany.jpg', 'w') {|f| f.write(file_object.body) }

Note: This method is more memory intensive as the entire object is loaded into memory before saving the file as in the example above.

File URL

To get a file's URL:

file.public_url

Copy File

Cloud Files supports copying files. To copy files into a container named "trip" with a name of "europe.jpg" do the following:

file.copy("trip", "europe.jpg")

To move or rename a file, perform a copy operation and then delete the old file:

file.copy("trip", "germany.jpg")
file.destroy

Delete File

To delete a file:

file.destroy

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

License

The gem is available as open source under the terms of the MIT License.