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# Copyright 2011-2013 Amazon.com, Inc. or its affiliates. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License"). You
# may not use this file except in compliance with the License. A copy of
# the License is located at
#
# http://aws.amazon.com/apache2.0/
#
# or in the "license" file accompanying this file. This file is
# distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF
# ANY KIND, either express or implied. See the License for the specific
# language governing permissions and limitations under the License.
module AWS
class ELB
class InstanceCollection
include Core::Collection::Simple
def initialize load_balancer, options = {}
@load_balancer = load_balancer
super
end
# Returns an {EC2::Instance} object with 3 extra methods added:
#
# * `#load_balancer`
# * `#remove_from_load_balancer`
# * `#elb_health`
#
# See {#health} for more information about what `#elb_health` returns.
#
# @return [EC2::Instance] Return an EC2::Instance object with additional
# methods added.
#
def [] instance_id
load_balancer = self.load_balancer
instance = EC2.new(:config => config).instances[instance_id]
Core::MetaUtils.extend_method(instance, :load_balancer) do
load_balancer
end
Core::MetaUtils.extend_method(instance, :elb_health) do
health = load_balancer.instances.health(id).first
health.delete(:instance)
health
end
Core::MetaUtils.extend_method(instance, :remove_from_load_balancer) do
load_balancer.instances.deregister(self)
end
instance
end
# Returns an array of instance health descriptions. Each description
# is a hash with the following entries:
#
# * `:instance` - The {EC2::Instance} being described.
# * `:description` - Provides a description of the instance.
# * `:state` - Specifies the current state of the instance.
# * `:reason_code` - Provides information about the cause of
# OutOfService instances. Specifically, it indicates whether the
# cause is Elastic Load Balancing or the instance behind the
# load balancer.
#
# You can get the health of all instances for this load balancer
# by passing no arguments to this method:
#
# # get the health of all instances in the collection
# load_balancer.instances.health.each do |instance_health|
# puts "Instance: " + instance_health[:instance].id
# puts "description: " + instance_health[:description]
# puts "state: " + instance_health[:state]
# puts "reason code: " + instance_health[:reason_code]
# end
#
# If you want the health of a specific list of instances, pass
# instance ids or instance objects to this method:
#
# # get the health for a few specific instances
# load_balancer.instances.health('i-12345', 'i-67890').each{|h| ... }
#
# ## Health for a Single Instance
#
# If you want the health of a single instance you can use the {#[]}
# instead:
#
# load_balancer.instances['i-123456'].elb_health
# # => { :state => ..., :reason_code => ..., :description => ... }
#
# @param [String,EC2::Instance] instances A list of instances to
# receive health information for.
#
# @return [Array<Hash>] Returns an array of hashes. Each hash represents
# the health of a single instance. Each hash includes the following
# entries:
#
def health *instances
instance_ids = instance_ids(instances)
opts = {}
opts[:load_balancer_name] = load_balancer.name
opts[:instances] = instance_ids unless instance_ids.empty?
client.describe_instance_health(opts).instance_states.map do |state|
{
:instance => self[state.instance_id],
:description => state.description,
:state => state.state,
:reason_code => state.reason_code,
}
end
end
# @return [LoadBalancer] Returns the load balancer this collection
# belongs to.
attr_reader :load_balancer
def register *instances
client.register_instances_with_load_balancer(
:load_balancer_name => load_balancer.name,
:instances => instance_ids(instances))
nil
end
alias_method :add, :register
def deregister *instances
client.deregister_instances_from_load_balancer(
:load_balancer_name => load_balancer.name,
:instances => instance_ids(instances))
nil
end
alias_method :remove, :deregister
protected
def instance_ids instances
instances.flatten.collect do |instance|
case instance
when EC2::Instance then { :instance_id => instance.id }
else { :instance_id => instance }
end
end
end
protected
def _each_item options = {}
load_balancer.instance_descriptions.each do |instance|
yield(self[instance[:instance_id]])
end
end
end
end
end
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