Merge pull request #44 from Lytro/cycle_multiple_instances_at_once

Cycle multiple instances at once

Gemfile.lock

@@ -2,7 +2,7 @@ PATH
   remote: .
   specs:
     aws-missing-tools (0.0.1)
-      aws-sdk
+      aws-sdk (~> 1.11)
 
 GEM
   remote: https://rubygems.org/
@@ -29,4 +29,4 @@ PLATFORMS
 
 DEPENDENCIES
   aws-missing-tools!
-  rspec
+  rspec (~> 2.12)

aws-missing-tools.gemspec

@@ -15,7 +15,7 @@ Gem::Specification.new do |gem|
   gem.require_paths = %w(lib)
   gem.version       = AwsMissingTools::VERSION
 
-  gem.add_dependency 'aws-sdk'
+  gem.add_dependency 'aws-sdk', '~> 1.11'
 
-  gem.add_development_dependency 'rspec'
+  gem.add_development_dependency 'rspec', '~> 2.12'
 end

lib/aws-missing-tools/aws-ha-release/aws-ha-release.rb

@@ -1,4 +1,3 @@
-require 'timeout'
 require 'optparse'
 
 module AwsMissingTools
@@ -22,6 +21,8 @@ module AwsMissingTools
         raise ArgumentError, "The Auto Scaling Group named #{@opts[:as_group_name]} does not exist in #{@opts[:region]}."
       end
 
+      @opts[:num_simultaneous_instances] = Integer(@opts[:num_simultaneous_instances]) rescue @group.auto_scaling_instances.count
+
       @max_size_change = 0
       @time_spent_inservice = 0
     end
@@ -31,7 +32,8 @@ module AwsMissingTools
         region: 'us-east-1',
         elb_timeout: 60,
         inservice_time_allowed: 300,
-        min_inservice_time: 30
+        min_inservice_time: 30,
+        num_simultaneous_instances: 1
       }
 
       OptionParser.new('Usage: aws-ha-release.rb -a <group name> [options]', 50) do |opts|
@@ -62,6 +64,10 @@ module AwsMissingTools
         opts.on('-s', '--aws_secret_key AWS_SECRET_KEY', 'AWS Secret Key') do |v|
           options[:aws_secret_key] = v
         end
+
+        opts.on('-n', '--num-simultaneous-instances NUM', 'Number of instances to simultaneously bring up per iteration') do |v|
+          options[:num_simultaneous_instances] = v
+        end
       end.parse!(arguments)
 
       raise OptionParser::MissingArgument, 'You must specify the AutoScaling Group Name: aws-ha-release.rb -a <group name>' if options[:as_group_name].nil?
@@ -85,55 +91,53 @@ module AwsMissingTools
 
       @group.suspend_processes PROCESSES_TO_SUSPEND
 
-      if @group.max_size == @group.desired_capacity
+      @max_size_change = determine_max_size_change
-        puts "#{@group.name} has a max-size of #{@group.max_size}. In order to recycle instances max-size will be temporarily increased by 1."
+      if @max_size_change > 0
-        @group.update(max_size: @group.max_size + 1)
+        puts "#{@group.name} has a max-size of #{@group.max_size}. In order to recycle instances max-size will be temporarily increased by #{@max_size_change}."
-        @max_size_change = 1
+        @group.update(max_size: @group.max_size + @max_size_change)
       end
 
-      @group.update(desired_capacity: @group.desired_capacity + 1)
+      @group.update(desired_capacity: @group.desired_capacity + @opts[:num_simultaneous_instances])
 
       puts "The list of instances in Auto Scaling Group #{@group.name} that will be terminated is:\n#{@group.auto_scaling_instances.map{ |i| i.ec2_instance.id }.to_ary}"
-      @group.auto_scaling_instances.each do |instance|
+      puts "The number of instances that will be brought up simultaneously is: #{@opts[:num_simultaneous_instances]}"
+      @group.auto_scaling_instances.to_a.each_slice(@opts[:num_simultaneous_instances]) do |instances|
         time_taken = 0
 
-        begin
-          Timeout::timeout(@opts[:inservice_time_allowed]) do
-
         until all_instances_inservice_for_time_period?(@group.load_balancers, INSERVICE_POLLING_TIME)
           puts "#{time_taken} seconds have elapsed while waiting for all instances to be InService for a minimum of #{@opts[:min_inservice_time]} seconds."
 
-              time_taken += INSERVICE_POLLING_TIME
+          if time_taken >= @opts[:inservice_time_allowed]
-              sleep INSERVICE_POLLING_TIME
-            end
-
-            puts "\nThe new instance was found to be healthy; one old instance will now be removed from the load balancers."
-            deregister_instance instance.ec2_instance, @group.load_balancers
-          end
-        rescue Timeout::Error => e
             puts "\nDuring the last #{time_taken} seconds, a new AutoScaling instance failed to become healthy."
             puts "The following settings were changed and will not be changed back by this script:\n"
 
             puts "AutoScaling processes #{PROCESSES_TO_SUSPEND} were suspended."
-          puts "The desired capacity was changed from #{@group.desired_capacity - 1} to #{@group.desired_capacity}."
+            puts "The desired capacity was changed from #{@group.desired_capacity - @opts[:num_simultaneous_instances]} to #{@group.desired_capacity}."
 
             if @max_size_change > 0
               puts "The maximum size was changed from #{@group.max_size - @max_size_change} to #{@group.max_size}"
             end
 
             raise
+          else
+            time_taken += INSERVICE_POLLING_TIME
+            sleep INSERVICE_POLLING_TIME
           end
+        end
+
+        puts "\nThe new instance(s) was/were found to be healthy; #{@opts[:num_simultaneous_instances]} old instance(s) will now be removed from the load balancers."
+        instances.each { |instance| deregister_instance(instance.ec2_instance, @group.load_balancers) }
 
         puts "Sleeping for the ELB Timeout period of #{@opts[:elb_timeout]}"
         sleep @opts[:elb_timeout]
 
-        puts "\nInstance #{instance.id} will now be terminated. By terminating this instance, the actual capacity will be decreased to 1 under desired-capacity."
+        puts "\nInstance(s) #{instances.map{ |i| i.ec2_instance.id }.join(', ')} will now be terminated. By terminating this/these instance(s), the actual capacity will be decreased to #{@opts[:num_simultaneous_instances]} under desired-capacity."
-        instance.terminate false
+        instances.each { |instance| instance.terminate false }
       end
 
-      puts "\n#{@group.name} had its desired-capacity increased temporarily by 1 to a desired-capacity of #{@group.desired_capacity}."
+      puts "\n#{@group.name} had its desired-capacity increased temporarily by #{@opts[:num_simultaneous_instances]} to a desired-capacity of #{@group.desired_capacity}."
-      puts "The desired-capacity of #{@group.name} will now be returned to its original desired-capacity of #{@group.desired_capacity - 1}."
+      puts "The desired-capacity of #{@group.name} will now be returned to its original desired-capacity of #{@group.desired_capacity - @opts[:num_simultaneous_instances]}."
-      @group.update(desired_capacity: @group.desired_capacity - 1)
+      @group.update(desired_capacity: @group.desired_capacity - @opts[:num_simultaneous_instances])
 
       if @max_size_change > 0
         puts "\n#{@group.name} had its max_size increased temporarily by #{@max_size_change} to a max_size of #{@group.max_size}."
@@ -146,6 +150,14 @@ module AwsMissingTools
       @group.resume_all_processes
     end
 
+    def determine_max_size_change
+      if @group.max_size - @group.desired_capacity < @opts[:num_simultaneous_instances]
+        @group.desired_capacity + @opts[:num_simultaneous_instances] - @group.max_size
+      else
+        0
+      end
+    end
+
     def deregister_instance(instance, load_balancers)
       load_balancers.each do |load_balancer|
         load_balancer.instances.deregister instance

spec/aws-missing-tools/aws-ha-release/aws-ha-release_spec.rb

@@ -28,6 +28,22 @@ describe 'aws-ha-release' do
         AwsMissingTools::AwsHaRelease.new(opts)
       }.should raise_error
     end
+
+    context 'number of simultaneous instances' do
+      before do
+        as.groups.create opts[1]
+        opts.push('--num-simultaneous-instances')
+      end
+      it 'with MAX, sets the option to the number of active instances' do
+        opts.push('MAX')
+        expect(AwsMissingTools::AwsHaRelease.new(opts).instance_variable_get('@opts')[:num_simultaneous_instances]).to eq 2
+      end
+
+      it 'with an integer, sets the option to that integer' do
+        opts.push('1')
+        expect(AwsMissingTools::AwsHaRelease.new(opts).instance_variable_get('@opts')[:num_simultaneous_instances]).to eq 1
+      end
+    end
   end
 
   describe '#parse_options' do
@@ -45,6 +61,7 @@ describe 'aws-ha-release' do
       expect(options[:aws_access_key]).not_to be_nil
       expect(options[:aws_secret_key]).not_to be_nil
       expect(options[:min_inservice_time]).not_to be_nil
+      expect(options[:num_simultaneous_instances]).not_to be_nil
     end
 
     context 'optional params' do
@@ -80,6 +97,20 @@ describe 'aws-ha-release' do
           expect(AwsMissingTools::AwsHaRelease.parse_options(options)[:min_inservice_time]).to eq 30
         end
       end
+
+      context 'number of instances to simultaneously bring up' do
+        it 'recognizes integer inputs' do
+          [%w(-a test_group -n 2), %w(-a test_group --num-simultaneous-instances 2)].each do |options|
+            expect(AwsMissingTools::AwsHaRelease.parse_options(options)[:num_simultaneous_instances]).to eq '2'
+          end
+        end
+
+        it 'recognizes the MAX keyword' do
+          [%w(-a test_group -n MAX), %w(-a test_group --num-simultaneous-instances MAX)].each do |options|
+            expect(AwsMissingTools::AwsHaRelease.parse_options(options)[:num_simultaneous_instances]).to eq 'MAX'
+          end
+        end
+      end
     end
   end
 
@@ -264,4 +295,37 @@ describe 'aws-ha-release' do
       expect(elb_two.instances).not_to include instance_one
     end
   end
+
+  describe '#determine_max_size_change' do
+    before do
+      @group = as.groups.create opts[1]
+    end
+
+    it 'does not change the desired capacity by default' do
+      @group.update(max_size: 4, desired_capacity: 2)
+      aws_ha_release = AwsMissingTools::AwsHaRelease.new(opts)
+
+      expect(aws_ha_release.determine_max_size_change).to eq 0
+    end
+
+    it 'adjusts the max size when it is equal to the desired capacity' do
+      @group.update(max_size: 2, desired_capacity: 2)
+      aws_ha_release = AwsMissingTools::AwsHaRelease.new(opts)
+
+      expect(aws_ha_release.determine_max_size_change).to eq 1
+    end
+
+    it 'accounts for num_simultaneous_instances' do
+      @group.update(max_size: 2, desired_capacity: 2)
+      aws_ha_release = AwsMissingTools::AwsHaRelease.new(%w(-a test_group --num-simultaneous-instances 2 -o testaccesskey -s testsecretkey -r test_region -i 1 -t 0 -m 5))
+
+      expect(aws_ha_release.determine_max_size_change).to eq 2
+
+      @group.update(max_size: 3, desired_capacity: 2)
+      expect(aws_ha_release.determine_max_size_change).to eq 1
+
+      @group.update(max_size: 4, desired_capacity: 2)
+      expect(aws_ha_release.determine_max_size_change).to eq 0
+    end
+  end
 end

spec/support/fake_auto_scaling.rb

@@ -48,7 +48,7 @@ module AWS
       end
 
       def auto_scaling_instances
-        @auto_scaling_instances ||= [AWS::FakeAutoScaling::Instance.new(self), AWS::FakeAutoScaling::Instance.new(self)]
+        @auto_scaling_instances ||= AWS::FakeCore::Data::List.new [AWS::FakeAutoScaling::Instance.new(self), AWS::FakeAutoScaling::Instance.new(self)]
       end
 
       def load_balancers

spec/support/fake_core_data_list.rb

@@ -0,0 +1,71 @@
+module AWS
+  module FakeCore
+    class Data
+      module MethodMissingProxy
+
+        protected
+
+        def method_missing *args, &block
+          if block_given?
+            return_value = @data.send(*args) do |*values|
+              yield(*values.flatten.map{|v| Data.cast(v) })
+            end
+            Data.cast(return_value)
+          else
+            Data.cast(@data.send(*args))
+          end
+        end
+
+      end
+
+      include MethodMissingProxy
+
+      def method_missing method_name, *args, &block
+        if
+          args.empty? and !block_given? and
+          key = _remove_question_mark(method_name) and
+          @data.has_key?(key)
+        then
+          Data.cast(@data[key])
+        else
+          super
+        end
+      end
+
+      class << self
+
+        # Given a hash, this method returns a {Data} object.  Given
+        # an Array, this method returns a {Data::List} object.  Everything
+        # else is returned as is.
+        #
+        # @param [Object] value The value to conditionally wrap.
+        #
+        # @return [Data,Data::List,Object] Wraps hashes and lists with
+        #   Data and List objects, all other objects are returned as
+        #   is.
+        #
+        def cast value
+          case value
+          when Hash then Data.new(value)
+          when Array then Data::List.new(value)
+          else value
+          end
+        end
+
+      end
+
+      class List
+        include MethodMissingProxy
+
+        def initialize(array)
+          @data = array
+        end
+
+        def to_ary
+          @data
+        end
+        alias_method :to_a, :to_ary
+      end
+    end
+  end
+end