Add alb_support recipes

taken from aws-samples/opsworks-example-cookbooks#9

Author: lordhx

alb_support/attributes/default.rb

@@ -0,0 +1,19 @@
+#
+# Cookbook Name:: alb_support
+# Attributes:: default
+#
+# Copyright 2017 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.
+#
+node.default[:alb_helper][:connection_draining_timeout] = 750
+node.default[:alb_helper][:state_check_frequency] = 30

alb_support/recipes/attach_to_alb.rb

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+#
+# Cookbook Name:: alb_support
+# Recipe:: attach_to_alb
+#
+# Copyright 2017 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.
+#
+chef_gem "aws-sdk-core" do
+  version "~> 2.6"
+  action :install
+end
+
+ruby_block "attach to ALB" do
+  block do
+    require "aws-sdk-core"
+
+    raise "alb_helper block not specified in layer JSON" if node[:alb_helper].nil?
+    raise "Target group ARN not specified in layer JSON" if node[:alb_helper][:target_group_arn].nil?
+
+    if ( Chef::VERSION.to_f >= 12.0 )
+      stack = search("aws_opsworks_stack").first
+      instance = search("aws_opsworks_instance", "self:true").first
+
+      stack_region = stack[:region]
+      ec2_instance_id = instance[:ec2_instance_id]
+    else
+      stack_region = node["opsworks"]["instance"]["region"]
+      ec2_instance_id = node["opsworks"]["instance"]["aws_instance_id"]
+    end
+
+    target_group_arn = node[:alb_helper][:target_group_arn]
+
+    Chef::Log.info("Creating ELB client in region #{stack_region}")
+    client = Aws::ElasticLoadBalancingV2::Client.new(region: stack_region)
+
+    Chef::Log.info("Registering EC2 instance #{ec2_instance_id} with target group #{target_group_arn}")
+
+    target_to_attach = {
+      target_group_arn: target_group_arn,
+      targets: [{ id: ec2_instance_id }]
+    }
+
+    client.register_targets(target_to_attach)
+  end
+  action :run
+end

alb_support/recipes/detach_from_alb.rb

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+#
+# Cookbook Name:: alb_support
+# Recipe:: detach_from_alb
+#
+# Copyright 2017 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.
+#
+chef_gem "aws-sdk-core" do
+  version "~> 2.6"
+  action :install
+end
+
+ruby_block "detach from ALB" do
+  block do
+    require "aws-sdk-core"
+
+    raise "alb_helper block not specified in layer JSON" if node[:alb_helper].nil?
+    raise "Target Group ARN not specified in layer JSON" if node[:alb_helper][:target_group_arn].nil?
+
+    connection_draining_timeout = node[:alb_helper][:connection_draining_timeout]
+    state_check_frequency = node[:alb_helper][:state_check_frequency]
+
+    Chef::Log.info("connection_draining_timeout: #{connection_draining_timeout}")
+    Chef::Log.info("state_check_frequency: #{state_check_frequency}")
+
+    if ( Chef::VERSION.to_f >= 12.0 )
+      stack = search("aws_opsworks_stack").first
+      instance = search("aws_opsworks_instance", "self:true").first
+
+      stack_region = stack[:region]
+      ec2_instance_id = instance[:ec2_instance_id]
+    else
+      stack_region = node["opsworks"]["instance"]["region"]
+      ec2_instance_id = node["opsworks"]["instance"]["aws_instance_id"]
+    end
+
+    target_group_arn = node[:alb_helper][:target_group_arn]
+
+    Chef::Log.info("Creating ELB client in region #{stack_region}")
+    client = Aws::ElasticLoadBalancingV2::Client.new(region: stack_region)
+
+    target_to_detach = {
+      target_group_arn: target_group_arn,
+      targets: [ { id: ec2_instance_id } ],
+    }
+
+    Chef::Log.info("Deregistering EC2 instance #{ec2_instance_id} from Target Group #{target_group_arn}")
+    client.deregister_targets(target_to_detach)
+
+    if connection_draining_timeout == 0
+      Chef::Log.info("connection_draining_timeout was set to 0 seconds. execution of shutdown recipes will not be delayed")
+    else
+      Chef::Log.info("delaying execution recipes until instance is drained from ALB or timeout of #{connection_draining_timeout} seconds elapses")
+      start_time = Time.now
+      loop do
+        response = client.describe_target_health(target_to_detach)
+        target_health_state = response[:target_health_descriptions].first[:target_health][:state]
+        Chef::Log.info("state of instance in ALB: #{target_health_state}")
+        seconds_elapsed = Time.now - start_time
+        Chef::Log.info("#{seconds_elapsed} of a maximum #{connection_draining_timeout} seconds elapsed")
+        Chef::Log.info("Sleeping #{ state_check_frequency} seconds")
+        break if target_health_state == "unused" || seconds_elapsed > connection_draining_timeout
+        sleep(state_check_frequency)
+      end
+    end
+  end
+  action :run
+end