Class: AWS::S3::Bucket

Inherits:
Object
  • Object
show all
Defined in:
lib/aws/s3/bucket.rb

Overview

Represents a bucket in S3.

Creating Buckets

You create a bucket by name. Bucket names must be globally unique and must be DNS compatible.

s3 = AWS::S3.new
bucket = s3.buckets.create('dns-compat-bucket-name')

Getting a Bucket

You can create a reference to a bucket, given its name.

bucket = s3.buckets['bucket-name'] # makes no request
bucket.exists? #=> returns true/false

Enumerating Buckets

The BucketCollection class is enumerable.

s3.buckets.each do |bucket|
  puts bucket.name
end

Deleting a Bucket

You can delete an empty bucket you own.

bucket = s3.buckets.create('my-temp-bucket')
bucket.objects['abc'].write('xyz')

bucket.clear! # deletes all object versions in batches
bucket.delete

You can alternatively call #delete! which will clear the bucket for your first.

bucket.delete!

Objects

Given a bucket you can access its objects, either by key or by enumeration.

bucket.objects['key'] #=> makes no request, returns an S3Object

bucket.objects.each do |obj|
  puts obj.key
end

See ObjectCollection and S3Object for more information on working with objects.

Bucket Policies and ACLs

You can control access to your bucket and its contents a number of ways. You can specify a bucket ACL (access control list) or a bucket policy.

ACLs

ACLs control access to your bucket and its contents via a list of grants and grantees.

Canned ACLs

The simplest way to specify an ACL is to use one of Amazon’s “canned” ACLs. Amazon accepts the following canned ACLs:

  • :private

  • :public_read

  • :public_read_write

  • :authenticated_read

  • :bucket_owner_read

  • :bucket_owner_full_control

You can specify a the ACL at bucket creation or later update a bucket.

# at create time, defaults to :private when not specified
bucket = s3.buckets.create('name', :acl => :public_read)

# replacing an existing bucket ACL
bucket.acl = :private

Grants

Alternatively you can specify a hash of grants. Each entry in the :grant hash has a grant (key) and a list of grantees (values). Valid grant keys are:

  • :grant_read

  • :grant_write

  • :grant_read_acp

  • :grant_write_acp

  • :grant_full_control

Each grantee can be a String, Hash or array of strings or hashes. The following example uses grants to provide public read to everyone while providing full control to a user by email address and to another by their account id (cannonical user id).

bucket = s3.buckets.create('name', :grants => {
  :grant_read => [
    { :uri => "http://acs.amazonaws.com/groups/global/AllUsers" },
  ],
  :grant_full_control => [
    { :id => 'abc...mno' }               # cannonical user id
    { :email_address => '[email protected]' }, # email address
  ]
})

ACL Object

Lastly, you can build an ACL object and use a Ruby DSL to specify grants and grantees. See ACLObject for more information.

# updating an existing bucket acl using ACLObject
bucket.acl.change do |acl|
  acl.grants.reject! do |g|
    g.grantee.canonical_user_id != bucket.owner.id
  end
end

Policies

You can also work with bucket policies.

policy = AWS::S3::Policy.new
policy.allow(
  :actions => [:put_object, :get_object]
  :resources => [bucket]
  :principals => :any)

bucket.policy = policy

See Core::Policy and Policy for more information on build policy objects.

Versioned Buckets

You can enable versioning on a bucket you control. When versioning is enabled, S3 will keep track of each version of each object you write to the bucket (even deletions).

bucket.versioning_enabled? #=> false
bucket.enable_versioning
# there is also a #disable_versioning method

obj = bucket.objects['my-obj']
obj.write('a')
obj.write('b')
obj.delete
obj.write('c')

obj.versions.each do |obj_version|
  if obj_version.delete_marker?
    puts obj_version.read
  else
    puts "- DELETE MARKER"
  end
end

Alternatively you can enumerate all versions of all objects in your bucket.

bucket.versions.each do |obj_version|
  puts obj_version.key + " : " + obj_version.version_id
end

See BucketVersionCollection, ObjectVersionCollection and ObjectVersion for more information on working with objects in a versioned bucket. Also see the S3 documentation for information on object versioning.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(name, options = {}) ⇒ Bucket

Returns a new instance of Bucket.

Parameters:

  • name (String)
  • options (Hash) (defaults to: {})

Options Hash (options):

  • :owner (String) — default: nil —

    The owner id of this bucket.



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# File 'lib/aws/s3/bucket.rb', line 200

def initialize(name, options = {})
  # the S3 docs disagree with what the service allows,
  # so it's not safe to toss out invalid bucket names
  # S3::Client.validate_bucket_name!(name)
  @name = name
  @owner = options[:owner]
  super
end

Instance Attribute Details

#name ⇒ String (readonly)

Returns The bucket name.

Returns:

  • (String) —

    The bucket name



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# File 'lib/aws/s3/bucket.rb', line 210

def name
  @name
end

Instance Method Details

#==(other) ⇒ Boolean

Returns true if the two buckets have the same name.

Returns:

  • (Boolean) —

    Returns true if the two buckets have the same name.



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# File 'lib/aws/s3/bucket.rb', line 303

def ==(other)
  other.kind_of?(Bucket) && other.name == name
end

#acl ⇒ AccessControlList

Returns the bucket’s access control list. This will be an instance of AccessControlList, plus an additional change method:

bucket.acl.change do |acl|
  acl.grants.reject! do |g|
    g.grantee.canonical_user_id != bucket.owner.id
  end
end

Returns:



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# File 'lib/aws/s3/bucket.rb', line 370

def acl

  resp = client.get_bucket_acl(:bucket_name => name)

  acl = AccessControlList.new(resp.data)
  acl.extend ACLProxy
  acl.bucket = self
  acl

end

#acl=(acl) ⇒ nil

Sets the bucket’s ACL (access control list). You can provide an ACL in a number of different formats.

Parameters:

  • acl (Symbol, String, Hash, AccessControlList) —

    Accepts an ACL description in one of the following formats:

    Canned ACL

    S3 supports a number of canned ACLs for buckets and objects. These include:

    • :private

    • :public_read

    • :public_read_write

    • :authenticated_read

    • :bucket_owner_read (object-only)

    • :bucket_owner_full_control (object-only)

    • :log_delivery_write (bucket-only)

    Here is an example of providing a canned ACL to a bucket:

    s3.buckets['bucket-name'].acl = :public_read

    ACL Grant Hash

    You can provide a hash of grants. The hash is composed of grants (keys) and grantees (values). Accepted grant keys are:

    • :grant_read

    • :grant_write

    • :grant_read_acp

    • :grant_write_acp

    • :grant_full_control

    Grantee strings (values) should be formatted like some of the following examples:

    id="8a6925ce4adf588a4532142d3f74dd8c71fa124b1ddee97f21c32aa379004fef"
uri="http://acs.amazonaws.com/groups/global/AllUsers"
emailAddress="[email protected]"

    You can provide a comma delimited list of multiple grantees in a single string. Please note the use of quotes inside the grantee string. Here is a simple example:

    {
  :grant_full_control => "emailAddress=\"[email protected]\", id=\"abc..mno\""
}

    See the S3 API documentation for more information on formatting grants.

    AcessControlList Object

    You can build an ACL using the AccessControlList class and pass this object.

    acl = AWS::S3::AccessControlList.new
acl.grant(:full_control).to(:canonical_user_id => "8a6...fef")
acl #=> this is acceptible

    ACL XML String

    Lastly you can build your own ACL XML document and pass it as a string.

    <<-XML
  <AccessControlPolicy xmlns="http://s3.amazonaws.com/doc/2006-03-01/">
    <Owner>
      <ID>8a6...fef</ID>
      <DisplayName>owner-display-name</DisplayName>
    </Owner>
    <AccessControlList>
      <Grant>
        <Grantee xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:type="Canonical User">
          <ID>8a6...fef</ID>
          <DisplayName>owner-display-name</DisplayName>
        </Grantee>
        <Permission>FULL_CONTROL</Permission>
      </Grant>
    </AccessControlList>
  </AccessControlPolicy> 
XML

Returns:

  • (nil) 


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# File 'lib/aws/s3/bucket.rb', line 385

def acl= acl
  client.set_bucket_acl(acl_options(acl).merge(:bucket_name => name))
  nil
end

#as_tree(options = {}) ⇒ Tree

Returns a tree that allows you to expose the bucket contents like a directory structure.

Parameters:

  • options (Hash) (defaults to: {})

Options Hash (options):

  • :prefix (String) — default: nil —

    Set prefix to choose where the top of the tree will be. A value of nil means that the tree will include all objects in the collection.

  • :delimiter (String) — default: '/' —

    The string that separates each level of the tree. This is usually a directory separator.

  • :append (Boolean) — default: true —

    If true, the delimiter is appended to the prefix when the prefix does not already end with the delimiter.

Returns:

See Also:



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# File 'lib/aws/s3/bucket.rb', line 538

def as_tree options = {}
  objects.as_tree(options)
end

#clear! ⇒ nil

Deletes all objects from this bucket.

Returns:

  • (nil) 


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# File 'lib/aws/s3/bucket.rb', line 271

def clear!
  versions.each_batch do |versions|
    objects.delete(versions)
  end
end

#delete ⇒ nil

Deletes the current bucket. An error will be raised if the bucket is not empty.

Returns:

  • (nil) 


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# File 'lib/aws/s3/bucket.rb', line 280

def delete
  client.delete_bucket(:bucket_name => @name)
  nil
end

#delete! ⇒ nil

Deletes all objects in a bucket and then deletes the bucket.

Returns:

  • (nil) 


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# File 'lib/aws/s3/bucket.rb', line 287

def delete!
  clear!
  delete
end

#empty? ⇒ Boolean

Returns true if the bucket has no objects (this includes versioned objects that are delete markers).

Returns:

  • (Boolean) —

    Returns true if the bucket has no objects (this includes versioned objects that are delete markers).



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# File 'lib/aws/s3/bucket.rb', line 224

def empty?
  versions.first ? false : true
end

#enable_versioning ⇒ nil

Enables versioning on this bucket.

Returns:

  • (nil) 


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# File 'lib/aws/s3/bucket.rb', line 236

def enable_versioning
  client.set_bucket_versioning(
    :bucket_name => @name,
    :state => :enabled)
  nil
end

#eql?(other_bucket) ⇒ Boolean

Returns true if the two buckets have the same name

Returns:

  • (Boolean) —

    Returns true if the two buckets have the same name



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# File 'lib/aws/s3/bucket.rb', line 308

def eql?(other_bucket)
  self == other_bucket
end

#exists? ⇒ Boolean

Note:

This method only indicates if there is a bucket in S3, not if you have permissions to work with the bucket or not.

Returns true if the bucket exists in S3.

Returns:

  • (Boolean) —

    Returns true if the bucket exists in S3.



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# File 'lib/aws/s3/bucket.rb', line 315

def exists?
  begin
    versioned? # makes a get bucket request without listing contents
               # raises a client error if the bucket doesn't exist or
               # if you don't have permission to get the bucket 
               # versioning status.
    true
  rescue Errors::NoSuchBucket => e
    false # bucket does not exist
  rescue Errors::ClientError => e
    true # bucket exists
  end
end

#lifecycle_configuration ⇒ BucketLifecycleConfiguration

The primary interface for editing the lifecycle configuration. See AWS::S3::BucketLifecycleConfiguration for more information.

Examples:

Adding rules to a bucket’s lifecycle configuration


bucket.lifecycle_configuration.update do
  add_rule 'cache-1/', 30
  add_rule 'cache-2/', 30
end

Deleting the lifecycle configuration


bucket.lifecycle_configuration.clear

Returns:



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# File 'lib/aws/s3/bucket.rb', line 467

def lifecycle_configuration
  @lifecycle_cfg ||= BucketLifecycleConfiguration.new(self)
end

#lifecycle_configuration=(config) ⇒ nil

You can call this method if you prefer to build your own lifecycle configuration.

bucket.lifecycle_configuration = <<-XML
  <LifecycleConfiguration>
    ...
  </LifecycleConfiguration>
XML

You can also use this method to copy a lifecycle configuration from another bucket.

bucket.lifecycle_configuration = other_bucket.lifecycle_configuration

If you call this method, passing nil, the lifecycle configuration for this bucket will be deleted.

Parameters:

  • config (String, Object) —

    You can pass an xml string or any other object that responds to #to_xml (e.g. BucketLifecycleConfiguration).

Returns:

  • (nil) 


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# File 'lib/aws/s3/bucket.rb', line 494

def lifecycle_configuration= config

  if config.nil?

    client_opts = {}
    client_opts[:bucket_name] = name
    client.delete_bucket_lifecycle_configuration(client_opts)

    @lifecycle_cfg = BucketLifecycleConfiguration.new(self, :empty => true)

  else
  
    xml = config.is_a?(String) ? config : config.to_xml

    client_opts = {}
    client_opts[:bucket_name] = name
    client_opts[:lifecycle_configuration] = xml
    client.set_bucket_lifecycle_configuration(client_opts)

    @lifecycle_cfg = BucketLifecycleConfiguration.new(self, :xml => xml)

  end

  nil

end

#location_constraint ⇒ String?

Returns the location constraint for a bucket (if it has one), nil otherwise.

Returns:

  • (String, nil) —

    Returns the location constraint for a bucket (if it has one), nil otherwise.



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# File 'lib/aws/s3/bucket.rb', line 230

def location_constraint
  client.get_bucket_location(:bucket_name => name).location_constraint
end

#multipart_uploads ⇒ MultipartUploadCollection

Returns Represents all of the multipart uploads that are in progress for this bucket.

Returns:



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# File 'lib/aws/s3/bucket.rb', line 343

def multipart_uploads
  MultipartUploadCollection.new(self)
end

#objects ⇒ ObjectCollection

Returns Represents all objects(keys) in this bucket.

Returns:



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# File 'lib/aws/s3/bucket.rb', line 331

def objects
  ObjectCollection.new(self)
end

#owner ⇒ String

Returns bucket owner id.

Returns:

  • (String) —

    bucket owner id



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# File 'lib/aws/s3/bucket.rb', line 293

def owner
  @owner || client.list_buckets.owner
end

#policy ⇒ Policy?

Returns the bucket policy. This will be an instance of Policy. The returned policy will also have the methods of PolicyProxy mixed in, so you can use it to change the current policy or delete it, for example:

if policy = bucket.policy
  # add a statement
  policy.change do |p|
    p.allow(...)
  end

  # delete the policy
  policy.delete
end

Note that changing the policy is not an atomic operation; it fetches the current policy, yields it to the block, and then sets it again. Therefore, it’s possible that you may overwrite a concurrent update to the policy using this method.

Returns:

  • (Policy, nil) —

    Returns the bucket policy (if it has one), or it returns nil otherwise.



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# File 'lib/aws/s3/bucket.rb', line 429

def policy
  resp = client.get_bucket_policy(:bucket_name => name)
  policy = Policy.from_json(resp.data[:policy])
  policy.extend(PolicyProxy)
  policy.bucket = self
  policy
rescue Errors::NoSuchBucketPolicy => e
  nil
end

#policy=(policy) ⇒ nil

Sets the bucket’s policy.

Parameters:

  • policy —

    The new policy. This can be a string (which is assumed to contain a valid policy expressed in JSON), a Policy object or any object that responds to to_json.

Returns:

  • (nil)

See Also:



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# File 'lib/aws/s3/bucket.rb', line 446

def policy=(policy)
  client.set_bucket_policy(:bucket_name => name, :policy => policy)
  nil
end

#presigned_post(options = {}) ⇒ Object

Generates fields for a presigned POST to this object. All options are sent to the PresignedPost constructor.

See Also:



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# File 'lib/aws/s3/bucket.rb', line 546

def presigned_post(options = {})
  PresignedPost.new(self, options)
end

#suspend_versioning ⇒ nil

Suspends versioning on this bucket.

Returns:

  • (nil) 


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# File 'lib/aws/s3/bucket.rb', line 245

def suspend_versioning
  client.set_bucket_versioning(
    :bucket_name => @name,
    :state => :suspended)
  nil
end

#url ⇒ String

Returns the url for this bucket.

Returns:

  • (String) —

    url to the bucket



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# File 'lib/aws/s3/bucket.rb', line 214

def url
  if client.dns_compatible_bucket_name?(name)
    "http://#{name}.s3.amazonaws.com/"
  else
    "http://s3.amazonaws.com/#{name}/"
  end
end

#versioning_enabled? ⇒ Boolean Also known as: versioned?

Returns true if version is enabled on this bucket.

Returns:

  • (Boolean) —

    returns true if version is enabled on this bucket.



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# File 'lib/aws/s3/bucket.rb', line 253

def versioning_enabled?
  versioning_state == :enabled
end

#versioning_state ⇒ Symbol

Returns the versioning status for this bucket. States include:

  • :enabled - currently enabled

  • :suspended - currently suspended

  • :unversioned - versioning has never been enabled

Returns:

  • (Symbol) —

    the versioning state



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# File 'lib/aws/s3/bucket.rb', line 265

def versioning_state
  client.get_bucket_versioning(:bucket_name => @name).status
end

#versions ⇒ BucketVersionCollection

Returns Represents all of the versioned objects stored in this bucket.

Returns:



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# File 'lib/aws/s3/bucket.rb', line 337

def versions
  BucketVersionCollection.new(self)
end