class EC2

# @attr_reader [String,nil] instance_id Returns the instance id if

# assigned to an EC2 instance, nil otherwise.

#

# @attr_reader [String,nil] allocation_id

# The ID representing the allocation of the address for use with Amazon

# VPC.

#

# @attr_reader [String] domain Indicates whether this elastic ip address

# is for EC2 instances ('standard') or VPC instances ('vpc').

#

# @attr_reader [String,nil] association_id The ID of the association

# between this elastic ip address and an EC2 VPC instance (VPC only).

#

# @attr_reader [String,nil] network_interface_id The ID of the network

# interface (VPC only).

#

# @attr_reader [String,nil] network_interface_owner_id

# The ID of the AWS account that owns the network interface (VPC only).

#

class ElasticIp < Resource

def initialize public_ip, options = {}

@public_ip = public_ip

super

end

# @return [String] The public IP address.

attr_reader :public_ip

alias_method :ip_address, :public_ip

attribute :instance_id

# vpc related attributes

attribute :allocation_id, :static => true

attribute :domain, :static => true

attribute :association_id

attribute :network_interface_id

attribute :network_interface_owner_id

populates_from(:describe_addresses) do |resp|

resp.address_index[public_ip]

end

# @return [Boolean] Returns true if this is an EC2 VPC Elastic IP.

def vpc?

domain == 'vpc'

end

# @return [Boolean] Returns true if this IP address is associated

# with an EC2 instance or a network interface.

def associated?

!!(instance_id || association_id)

end

alias_method :attached?, :associated?

# @return [Instance,nil] If associated, returns the {Instance} this

# elastic IP address is associated to, nil otherwise.

def instance

if instance_id = self.instance_id

Instance.new(instance_id, :config => config)

end

end

# @return [NetworkInterface,nil] Returns the network interface this

# elastic ip is associated with. Returns `nil` if this is not

# associated with an elastic ip address.

def network_interface

if nid = network_interface_id

NetworkInterface.new(nid, :config => config)

end

end

# Releases the elastic IP address.

#

# (For non-VPC elastic ips) Releasing an IP address automatically

# disassociates it from any instance it's associated with.

#

# @return [nil]

def delete

if vpc?

client.release_address(:allocation_id => allocation_id)

else

client.release_address(:public_ip => public_ip)

end

nil

end

alias_method :release, :delete

# Associates this elastic IP address with an instance or a network

# interface. You may provide `:instance` or `:network_interface`

# but not both options.

#

# # associate with an instance

# eip.associate :instance => 'i-12345678'

#

# # associate with a network interface

# eip.associate :network_interface => 'ni-12345678'

#

# @param [Hash] options

#

# @option options [String,Instance] :instance The id of an instance

# or an {Instance} object.

#

# @option options [String,NetworkInterface] :network_interface The id

# of a network interface or a {NetworkInterface} object.

#

# @return [String] Returns the resulting association id.

#

def associate options

client_opts = {}

[:instance,:network_interface,:private_ip_address].each do |opt|

if value = options[opt]

key = ( opt.to_s=='instance' || opt.to_s=='network_interface' ? opt.to_s+"_id" : opt.to_s )

client_opts[:"#{key}"] = value.is_a?(Resource) ? value.id : value

end

end

if vpc?

client_opts[:allocation_id] = allocation_id

else

client_opts[:public_ip] = public_ip

end

resp = client.associate_address(client_opts)

resp.data[:association_id]

end

# Disassociates this elastic IP address from an EC2 instance.

# Raises an exception if this elastic IP is not currently

# associated with an instance.

# @return [nil]

def disassociate

if vpc?

client.disassociate_address(:association_id => association_id)

else

client.disassociate_address(:public_ip => public_ip)

end

nil

end

# @return [Boolean] Returns true the elastic ip address exists in

# your account.

def exists?

begin

get_resource

true

rescue Errors::InvalidAddress::NotFound

false

end

end

# @return [String] Returns the public IP address

def to_s

public_ip.to_s

end

# @api private

protected

def resource_id_method

:public_ip

end

# @api private

protected

def response_id_method

:public_ip

end

# @api private

protected

def describe_call_name

:describe_addresses

end

# @api private

protected

def self.describe_call_name

:describe_addresses

end

end

end