Module: Gcloud::Storage

Defined in:
lib/gcloud/storage.rb,
lib/gcloud/storage/file.rb,
lib/gcloud/storage/bucket.rb,
lib/gcloud/storage/errors.rb,
lib/gcloud/storage/project.rb,
lib/gcloud/storage/file/acl.rb,
lib/gcloud/storage/file/list.rb,
lib/gcloud/storage/connection.rb,
lib/gcloud/storage/bucket/acl.rb,
lib/gcloud/storage/credentials.rb,
lib/gcloud/storage/bucket/list.rb,
lib/gcloud/storage/bucket/cors.rb,
lib/gcloud/storage/file/verifier.rb

Overview

Google Cloud Storage

Google Cloud Storage is an Internet service to store data in Google's cloud. It allows world-wide storage and retrieval of any amount of data and at any time, taking advantage of Google's own reliable and fast networking infrastructure to perform data operations in a cost effective manner.

Gcloud's goal is to provide a API that is familiar and comfortable to Rubyists. Authentication is handled by Gcloud#storage. You can provide the project and credential information to connect to the Storage service, or if you are running on Google Compute Engine this configuration is taken care of for you.

require "gcloud"

gcloud = Gcloud.new "my-todo-project",
                    "/path/to/keyfile.json"
storage = gcloud.storage

bucket = storage.bucket "my-bucket"
file = bucket.file "path/to/my-file.ext"

You can learn more about various options for connection on the Authentication Guide.

To learn more about Cloud Storage, read the Google Cloud Storage Overview .

Retrieving Buckets

A Bucket is the container for your data. There is no limit on the number of buckets that you can create in a project. You can use buckets to organize and control access to your data. Each bucket has a unique name, which is how they are retrieved: (See Project#bucket)

require "gcloud"

gcloud = Gcloud.new
storage = gcloud.storage

bucket = storage.bucket "my-todo-app"

You can also retrieve all buckets on a project: (See Project#buckets)

require "gcloud"

gcloud = Gcloud.new
storage = gcloud.storage

all_buckets = storage.buckets

If you have a significant number of buckets, you may need to paginate through them: (See Bucket::List#token)

require "gcloud"

gcloud = Gcloud.new
storage = gcloud.storage

all_buckets = []
tmp_buckets = storage.buckets
while tmp_buckets.any? do
  tmp_buckets.each do |bucket|
    all_buckets << bucket
  end
  # break loop if no more buckets available
  break if tmp_buckets.token.nil?
  # get the next group of buckets
  tmp_buckets = storage.buckets token: tmp_buckets.token
end

Creating a Bucket

A unique name is all that is needed to create a new bucket: (See Project#create_bucket)

require "gcloud"

gcloud = Gcloud.new
storage = gcloud.storage

bucket = storage.create_bucket "my-todo-app-attachments"

Retrieving Files

A File is an individual pieces of data that you store in Google Cloud Storage. Files contain the data stored as well as metadata describing the data. Files belong to a bucket and cannot be shared among buckets. There is no limit on the number of objects that you can create in a bucket.

Files are retrieved by their name, which is the path of the file in the bucket: (See Bucket#file)

require "gcloud"

gcloud = Gcloud.new
storage = gcloud.storage

bucket = storage.bucket "my-todo-app"
file = bucket.file "avatars/heidi/400x400.png"

You can also retrieve all files in a bucket: (See Bucket#files)

require "gcloud"

gcloud = Gcloud.new
storage = gcloud.storage

bucket = storage.bucket "my-todo-app"
all_files = bucket.files

Or you can retrieve all files in a specified path:

require "gcloud"

gcloud = Gcloud.new
storage = gcloud.storage

bucket = storage.bucket "my-todo-app"
avatar_files = bucket.files prefix: "avatars/"

If you have a significant number of files, you may need to paginate through them: (See File::List#token)

require "gcloud"

gcloud = Gcloud.new
storage = gcloud.storage

bucket = storage.bucket "my-todo-app"

all_files = []
tmp_files = bucket.files
while tmp_files.any? do
  tmp_files.each do |file|
    all_files << file
  end
  # break loop if no more files available
  break if tmp_files.token.nil?
  # get the next group of files
  tmp_files = bucket.files token: tmp_files.token
end

Creating a File

A new File can be uploaded by specifying the location of a file on the local file system, and the name/path that the file should be stored in the bucket. (See Bucket#create_file)

require "gcloud"

gcloud = Gcloud.new
storage = gcloud.storage

bucket = storage.bucket "my-todo-app"
bucket.create_file "/var/todo-app/avatars/heidi/400x400.png",
                   "avatars/heidi/400x400.png"

A note about large uploads

You may encounter a Broken pipe (Errno::EPIPE) error when attempting to upload large files. To avoid this problem, add the httpclient gem to your project, and the line (or lines) of configuration shown below. These lines must execute after you require gcloud but before you make your first gcloud connection. The first statement configures Faraday to use httpclient. The second statement, which should only be added if you are using a version of Faraday at or above 0.9.2, is a workaround for this gzip issue.

require "gcloud"

# Use httpclient to avoid broken pipe errors with large uploads
Faraday.default_adapter = :httpclient

# Only add the following statement if using Faraday >= 0.9.2
# Override gzip middleware with no-op for httpclient
Faraday::Response.register_middleware :gzip =>
                                        Faraday::Response::Middleware

gcloud = Gcloud.new
storage = gcloud.storage

Downloading a File

Files can be downloaded to the local file system. (See File#download)

require "gcloud"

gcloud = Gcloud.new
storage = gcloud.storage

bucket = storage.bucket "my-todo-app"
file = bucket.file "avatars/heidi/400x400.png"
file.download "/var/todo-app/avatars/heidi/400x400.png"

Using Signed URLs

Access without authentication can be granted to a File for a specified period of time. This URL uses a cryptographic signature of your credentials to access the file. (See File#signed_url)

require "gcloud"

gcloud = Gcloud.new
storage = gcloud.storage

bucket = storage.bucket "my-todo-app"
file = bucket.file "avatars/heidi/400x400.png"
shared_url = file.signed_url method: "GET",
                             expires: 300 # 5 minutes from now

Controlling Access to a Bucket

Access to a bucket is controlled with Bucket#acl. A bucket has owners, writers, and readers. Permissions can be granted to an individual user's email address, a group's email address, as well as many predefined lists. See the Access Control guide for more.

Access to a bucket can be granted to a user by appending "user-" to the email address:

require "gcloud"

gcloud = Gcloud.new
storage = gcloud.storage

bucket = storage.bucket "my-todo-app"

email = "[email protected]"
bucket.acl.add_reader "user-#{email}"

Access to a bucket can be granted to a group by appending "group-" to the email address:

require "gcloud"

gcloud = Gcloud.new
storage = gcloud.storage

bucket = storage.bucket "my-todo-app"

email = "[email protected]"
bucket.acl.add_reader "group-#{email}"

Access to a bucket can also be granted to a predefined list of permissions:

require "gcloud"

gcloud = Gcloud.new
storage = gcloud.storage

bucket = storage.bucket "my-todo-app"

bucket.acl.public!

Controlling Access to a File

Access to a file is controlled in two ways, either by the setting the default permissions to all files in a bucket with Bucket#default_acl, or by setting permissions to an individual file with File#acl.

Access to a file can be granted to a user by appending "user-" to the email address:

require "gcloud"

gcloud = Gcloud.new
storage = gcloud.storage

bucket = storage.bucket "my-todo-app"
file = bucket.file "avatars/heidi/400x400.png"

email = "[email protected]"
file.acl.add_reader "user-#{email}"

Access to a file can be granted to a group by appending "group-" to the email address:

require "gcloud"

gcloud = Gcloud.new
storage = gcloud.storage

bucket = storage.bucket "my-todo-app"
file = bucket.file "avatars/heidi/400x400.png"

email = "[email protected]"
file.acl.add_reader "group-#{email}"

Access to a file can also be granted to a predefined list of permissions:

require "gcloud"

gcloud = Gcloud.new
storage = gcloud.storage

bucket = storage.bucket "my-todo-app"
file = bucket.file "avatars/heidi/400x400.png"

file.acl.public!

Defined Under Namespace

Classes: ApiError, Bucket, Error, File, FileVerificationError, Project, SignedUrlUnavailable