A quick intro to hacking on Puppet modules from Nan Liu and Dan Bode.

1. Stanford
Hackathon
(D|N)an - Business Development
(d|n)an@puppetlabs.com | #puppet
PuppetLabs - 2012

2. Overview

3. Overview

4. Puppet vs. Scripts
• Abstraction
• Idempotent
• Declarative

5. Abstraction
• Puppet packages:
package { ‘sshd’:
ensure => ‘present’,
}
• Packages commands:
yum/rpm
apt/deb
pkgadd/pkgutil
gem
...

6. Idempotent
• Script:
service sshd stop
Stopping sshd: [ OK ]
service sshd stop
Stopping sshd: [FAILED]
• Puppet:
puppet resource service sshd ensure=stopped ...
notice: /Service[sshd]/ensure: ensure changed 'running' to
'stopped'
puppet resource service sshd ensure=stopped ...

7. Declarative
Puppet internal Puppet user
System state (is): Desire state (should):
service sshd status service { 'sshd':
ensure => running,
}
system == desire
No
noop?
No
Remedy (sync):
Report
service sshd start

8. Puppet Resource
• Puppet manifest building block
• file
• user
• package
• service
• ...

9. Puppet Resource
• puppet resource <type> [title]

10. Puppet Manifests
• package { ‘ssh’:
ensure => ‘present’,
}
file { ‘/etc/sshd/sshd_config’:
owner => ‘root’,
group => ‘root’,
mode => ‘0600’,
source => ‘puppet:///modules/sshd/sshd_config’,
require => Package[‘ssh’],
}
service { ‘sshd’:
ensure => ‘running’,
subscribe => File[‘/etc/sshd/ssd_config’],
}

11. Puppet
Organization
manifests package { 'sshd':
node lisa { ensure => latest,
class {lisa { { }
node "ssh": class ssh { }
} class {lisa
node "ssh": } class ssh {
…
} class { "ssh": } } …
} } file { 'sshd_config':
source => "puppet:///..."
site.pp }
files
native resource (ruby)
# sshd_config,v 1.81
# # sshd_config,v 1.81
This is the sshd server
# This is the sshd server
system-wide configuration
system-wide configuration ssh::root_key {
… key => "AAAA…"
…
}
ssh module define resource (puppet)

12. Module
Directories
• manifests: puppet manifests
(*.pp)
• files: configuration file
• templates: ERB template (*.erb)
• lib: ruby (*.rb)
• tests: puppet unit testing (*.pp)

13. Organization

14. Module
Development
• Syntax Check
• Unit Test
• Acceptance Test
• Environment -> Deploy

15. Puppet Syntax
• puppet parser validate
• git commit hook
• vim syntastic
• geppetto (eclipse IDE)
• puppet best practice
• puppet-lint

16. Unit Test
• puppet cucumber
• rspec-puppet (Tim Sharpe)

17. rspec-puppet
• verify resources in catalog
• validate different facts
• validate different parameters

18. rspec-puppet
• rspec-puppet directory
structure:
• <module_name>/spec
/classes
/defines
/fixtures
/manifests/site.pp

19. rspec-puppet
• #rspec_test/manifests/init.pp
class rspec_test($message = ‘default’) {
notify { $message: }
}
• #rspec_test/spec/rspec_test_spec.rb
describe 'rspec_test' do
describe 'with default parameters' do
it { should contain_notify('default') }
end
describe 'when overriding message' do
let :params do {:message => 'override'} end
it { should contain_notify('override') }
end
end

20. Travis CI
• Github integration
• Invoke test on git push
• Simple test matrix

21. .travis.yml
• language: ruby
before_script:
- 'git clone git://github.com/puppetlabs/puppetlabs-
stdlib.git spec/fixtures/modules/stdlib'
rvm:
- 1.8.7
- 1.9.2
script: "rake spec"
env:
- PUPPET_VERSION=2.6.12
- PUPPET_VERSION=2.7.12
matrix:
exclude:
- rvm: 1.9.2
env: PUPPET_VERSION=2.6.12

22. Gemfile
• source :rubygems
puppetversion = ENV.key?('PUPPET_VERSION') ?
"= #{ENV['PUPPET_VERSION']}" : ['>= 2.7']
gem 'puppet', puppetversion
group :test do
gem 'rake', '>= 0.9.0'
gem 'rspec', '>= 2.8.0'
gem 'rspec-puppet', '>= 0.1.1'
end

23. Travis CI

24. Acceptance
Testing
• vagrant box
• veewee (basebox)
• http://vagrantbox.es
• vagrant init
• vagrant up
• vagrant provision

25. Vagrant
• config.vm.provision :puppet do |puppet|
puppet.manifests_path = "manifests"
puppet.manifest_file = "oneiric.pp"
end
• config.vm.network :hostonly, "10.0.2.15"
• config.vm.share_folder("v-root", "/vagrant", ".", :nfs
=> true)

26. Puppet Modules
• forge.puppetlabs.com
• www.github.com/puppetlabs
• Bring your own module!

27. Module Projects?
• Module cleanup
• puppet-lint (best practice)
• Module test
• rspec puppet
• travis ci
• Module development

28. Puppet Projects?
• Puppet issues:
projects.puppetlabs.com
• Puppettools:
geppeto
puppet-lint
rspec-puppet

29. We are hiring!

30. We are hiring!