AWS OpsWorks lets you model your application with layers that define the building blocks of your application: load balancers, application servers, databases, etc. But did you know that you can also extend OpsWorks layers or build your own custom layers? Whether you need to perform a specific task or install a new software package, OpsWorks gives you the tools to install and configure your instances consistently, and evolve them in an automated and predictable fashion through your application’s lifecycle. We'll dive into the development process including how to use attributes, recipes, and lifecycle events; show how to develop your environment locally; and provide troubleshooting steps that reduce your development time.

1. DMG304 - AWS OpsWorks Under the Hood
Jonathan Weiss & Reza Spagnolo, Amazon Web Services
November 14th, 2013
© 2013 Amazon.com, Inc. and its affiliates. All rights reserved. May not be copied, modified, or distributed in whole or in part without the express consent of Amazon.com, Inc.

2. Agenda
• AWS OpsWorks event life cycle
• How to use custom cookbooks: MongoDB
• Chef in AWS OpsWorks vs. Chef server

3. Event Life Cycle

4. The Heart of the Service
Agent on each
Agent on each
Amazon EC2 instance
EC2 instance
Understands a set of commands that are
triggered by AWS OpsWorks.
The agent then runs a Chef solo run.

5. Life Cycle Events
setup
configure
deploy
undeploy
shutdown

6. new
Continuous Configuration

7. new
Continuous Configuration

8. Continuous Configuration
configure
online
new
setup

9. Continuous Configuration
configure
online
new
setup
deploy

10. Continuous Configuration
configure
shutting
down
online
new / stopped
setup
terminating
configure
deploy

11. Setup Event
• Sent when instance boots
• Includes deploy event
• Use for initial installation
of software & services

12. Setup Event – Recipe Execution Order
AWS
OpsWorks
setup recipes
Your setup
recipes
AWS
OpsWorks
deploy
recipes
Your deploy
recipes

13. Configure Event
• Sent to all instances when
any instance enters or
leaves online state
• Use for making sure the
configuration is up-to-date

14. Deploy Event
• Sent by deploy via UI/API
and is also part of each
setup
• Use for custom deployment

15. Undeploy Event
• Sent via UI/API when
apps are deleted
• Use to remove apps from
running instances

16. Shutdown Event
• Sent when an instance
is shut down
• ~45s to execute
• Use for clean shutdown

17. Customizing AWS OpsWorks

18. control
simple
Customization Options
Built-in layers
Override Chef attributes via custom JSON
Override Chef attributes via custom cookbook
Overwrite Chef template file
Deploy hooks
Provide custom recipe to extend built-in layer
Provide custom recipe to create custom layer

19. Built-in Layers
Rails
MySQL
PHP
HAProxy
Node.js
Memcached
Java
Ganglia
Open Source at http://github.com/aws/opsworks-cookbooks

20. Chef Templates
Template for /etc/apache2/apache2.conf

21. Custom JSON
Override Chef attributes of built-in cookbooks
# in apache2/attributes/default.rb
default[:apache][:timeout] = 120
node.apache.timeout
# => 60
{
‘apache2‘: {‘timeout‘: 60 }
}

22. Custom Cookbook Attributes
Override Chef attributes of built-in cookbooks
# in apache2/attributes/default.rb
default[:apache][:timeout] = 120
node.apache.timeout
# => 60
# in mycookbook/attributes/apache.rb
set[:apache][:timeout] = 60

23. Overwriting Chef Templates
Provide custom file at same location
$ cat mycookbook-repo/apache2/templates/apache2.conf.erb
...
#
# Example custom content
#
LogLevel error
# change default type
DefaultType text/json

24. Deploy Hooks
$ ls myapp/deploy/
before_migrate.rb
before_symlink.rb
before_restart.rb
after_restart.rb
Hooks use Capistrano syntax

25. Example Deploy Hook
Rails asset pipeline support
$ cat deploy/before_symlink.rb
run "cd #{release_path} &&
RAILS_ENV=production bundle exec rake assets:precompile
sudo "/etc/init.d/myservice restart"

26. Custom Cookbooks

27. Custom Layers
Run anything that is scriptable with Chef
–
–
–
–
–
Erlang app server
Cassandra DB cluster
C daemon
Custom PHP install
…

28. Custom Layers

29. Custom Layers

30. Custom Layers
$ ls mycookbook-repo/erlang/
recipes/install.rb
recipes/uninstall.rb
$ ls mycookbook-repo/e-app/
recipes/deploy.rb
recipes/undeploy.rb

31. Custom Layers

32. Different Configuration Managers
Call bash script from Chef
bash "legacy bootstrap" do
user "root"
cwd "/tmp"
code <<-EOH
wget http://www.example.com/installer.tar.gz
tar -zxf installer.tar.gz
cd installer
./configure
make
make install
EOH
end

33. AWS OpsWorks Attribute Tree
Sources:
Custom JSON
Stack configuration JSON
Deployment JSON
Cookbook attributes
Chef - Ohai

34. AWS OpsWorks Attribute Tree - Categories
Multiple categories and namespaces
node[:opsworks]
node[:opsworks][:layers]
node[:opsworks][:instance]
node[:opsworks][:stack]
Built in layer specific -> i.e. node[:opsworks_java]
Built in recipe specific -> i.e. node[:apache2]

35. Walkthrough:
MongoDB on AWS OpsWorks

36. Architecture – MongoDB Replica Set

37. Objectives
•
•
•
•
MongoDB as custom layer
Use community cookbook
Extend Java application layer
Manage system life cycle

38. MongoDB Custom Layer
• Chef community cookbook for MongoDB
– https://github.com/edelight/chef-mongodb
• Cookbook functionality
–
–
–
–
Install
Register with peers
Service startup
Clean shutdown

39. MongoDB Custom Layer - Recipes

40. MongoDB Custom Layer - Changes
Enable node discovery through AWS OpsWorks JSON
def replicaset_members(node)
replicaset_layer = node['opsworks']['instance']['layers'].first
instances = node['opsworks']['layers'][replicaset_layer]['instances']
instances.map do |name, instance|
member = Chef::Node.new
member.name(name)
member.default['hostname'] = name
member.default['fqdn'] = instance['private_dns_name']
member.default['ipaddress'] = instance['private_ip']
member
end
end

41. MongoDB Custom Layer - Configuration
Custom JSON in MongoDB stack
Made available to every
Chef recipe
Integrates out of the box
with community cookbook

42. MongoDB Custom Layer – EBS Setup
AWS OpsWorks support for EBS RAID
Setup the mount point passed through custom JSON

43. Extend Application Layer - Configure
Leverage configure
event definition of
built-in Java layer

44. Extend Application Layer - Template
Override application context template of built-in Java layer
$ cat opsworks_java/templates/default/webapp_context.xml.erb
<%
replicaset_name = node['mongodb']['replicaset_name']
mongo_nodes = node['opsworks']['layers'][replicaset_name]
['instances'].keys.map{|name| "#{name}:27017"}.join(",")
%>
<Context>
<Environment name="mongoNodes"
type="java.lang.String"
value="<%= mongo_nodes %>" />
</Context>

45. Package Your Custom Cookbook
Package your cookbook and its dependencies in a
single archive
java-mongodb-compound-cookbook/
├── apt/
├── build-essential/
├── python/
├── yum/
├── opsworks_java/
└── chef-mongodb/

46. Done !

47. Chef in AWS OpsWorks
vs.
Chef Server

48. Main Differences
•
•
•
•
•
Chef setup
One run vs. discrete events
Push vs. pull
Discovery: search & AWS OpsWorks attribute tree
Data bags

49. Chef Setup
Chef Solo
&
AWS OpsWorks Backend
Chef Client
&
Chef Server

50. Life Cycle Events
• Give you fine-grained control
• Faster to execute
• Context

51. Push vs. Pull
• On-demand and automatic
• Respond immediately to changes in the stack

52. Discovery: Chef Search
AWS OpsWorks does not offer attribute search
Alternative:
node[:opsworks] with similar capabilities
to partial_search

53. AWS OpsWorks Attribute Tree
Find all Rails application servers
rails_servers = node['opsworks']['layers']['rails-app']['instances']
rails_ips = rails_servers.map{|i| i['private_ip'] }
template "/etc/rails-server.conf" do
...
variables({
:ips => rails_server_ips
})
end

54. Encrypted Data Bags
• Upload encrypted JSON to S3
• Have instances access via IAM roles in a recipe

55. Custom JSON
Arbitrary JSON on stack that is available in Chef
{
‘foo‘: {
‘bar‘: true,
‘baz‘: false
}
}
if node.foo.bar
...
elsif node.foo.baz
...
end

56. Store Secrets on Amazon S3
Access from instance via instance profiles
bucket = node['acme']['bucket']
key = node['acme']['key']
s3 = AWS::S3.new
obj = s3.buckets[bucket].objects[key]
obj.read

57. Recap

58. AWS OpsWorks
• Life cycle framework
• Highly customizable
• Run anything

59. More Information about AWS OpsWorks
•
•
•
•
•
•
Do the AWS OpsWorks lab!
Find us on the AWS Booth
Follow us on twitter @AWSOpsWorks
Find us on YouTube
Blog: http://blogs.aws.amazon.com/application-management
Survey: http://tinyurl.com/OpsWorksSurvey2013

60. Recommend Sessions
DMG305 - How Intuit Leveraged AWS OpsWorks
as the Engine of Our PaaS
Capen Brinkley & Rick Mendes of Intuit, inc.
Thursday, Nov 14, 4:15 PM - 5:15 PM – Murano 3206

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presentation
DMG304
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