Shawn Smiley, Lead Architect, for Achieve Internet explains Puppet Scripting for SANDCamp 2013

1. Introduction to Puppet
Scripting
Shawn S. Smiley
Lead Architect
Achieve Internet
shawn.smiley@achieveinternet.com

2. What is puppet?
“Puppet is IT automation software
that helps system administrators
manage infrastructure throughout its
lifecycle, from provisioning and
configuration to patch management
and compliance.”
Source: www.puppetlabs.com/puppet/what-is-puppet

3. What does that mean?
• You can setup a new server in
minutes vs. hours!
• You can be sure your server
configurations are consistent.
• You can easily deploy
configuration changes to
multiple servers.
Image Source: http://www.forbes.com/sites/kenkrogue/2012/09/07/the-most-important-interview-question-never-asked/

4. Quick Demo
Image source: http://gyaniji.blogspot.com/2011/12/demo-of-ad-posting-job.html

5. What happened?
• Puppet analyzed the scripts to build a picture of what the
server should look like.
• Puppet then compared that to what the server actually
looks like.
• It then generates and executes scripts to make the server
configuration match that in the puppet scripts.

6. How vs. What
• Why is it better to describe what a system looks like
rather than how to configure a system?
• When you describe what a system looks like, you can
repeatedly rerun the process without fear of breaking the
system.
• Can build platform independent scripts.

7. What are the pieces?
• Puppet Software
• Module Library
• Node configuration file
• [optional] Puppet Master

8. Modules
What are they?
• Self-contained packages that describe an aspect of a
system (e.g. “Apache” or “MySQL”)
Are there existing packages I can leverage?
• http://forge.puppetlabs.com
• http://github.com
Where do I put them?
• /usr/share/puppet/modules
• /etc/puppet/modules

9. File Organization
• manifests
• site.pp
• nodes.pp
• modules
• module1
• manifests
 init.pp
• files
• templates
• module2

10. Demo: Folder Structure
Image source: http://gyaniji.blogspot.com/2011/12/demo-of-ad-posting-job.html

11. Basic Syntax
• Follows basic Ruby language syntax.
• Does not fully implement the Ruby language though, only
a subset is allowed in your puppet files.
To define an item: To execute an item:
type title($arg1) { include “title”
description of resource state
} type {“title”: }
type {“title”:
arg1 => ‘hello’
}

12. Demo: Simple script
Image source: http://gyaniji.blogspot.com/2011/12/demo-of-ad-posting-job.html

13. Resource Types
• Are puppet libraries that are used to interact with the
system.
• Puppet comes with a wide range of resource types:
• exec
• package
• file
• service
• notify
Full list:
http://docs.puppetlabs.com/references/latest/type.html

14. Facter
What are facts?
• Global variables with information about the system that
the script is running on.
How do I see the available variables?
• facter -p
How do I use them?
• $::variable_name

15. Templates
• Templates are files that use a simple markup language to
insert dynamic values.
• Templates have an .erb extension
• Typically used with the File resource. e.g.:
file {'ntp.conf':
path => '/etc/ntp.conf',
ensure => file,
content => template('ntp/ntp.conf.erb'),
owner => root,
mode => 0644,
}

16. Relationships
• Package[“ntp”] -> File[„ntp.conf‟] ~> Service[„ntpd‟]
• “before”, “require”
• “subscribe”, “notify”
http://docs.puppetlabs.com/puppet/2.7/reference/lang_relati
onships.html#relationship-metaparameters
http://docs.puppetlabs.com/puppet/2.7/reference/lang_relati
onships.html#chaining-arrows

17. User-Defined Types
• Similar to functions in most languages.
• Only way to do iterations currently.
• Call the Type with an array.
define apache::vhost() {
$docroot = “/var/www/${name}”
}
$sites = [‘site1’, ‘site2’]
apache::vhost {$sites: }

18. References
Books
• Managing Infrastructure with Puppet
(ISBN: 978-1-4493-0763-9)
• Pro Puppet (ISBN: 978-1-4302-3057-1)
Websites
• http://www.puppetlabs.com
• http://docs.puppetlabs.com/
• http://forge.puppetlabs.com/

19. Q&A