Stop Writing Puppet Modules: A Guide to Best Practices in the Puppet Community (Intermediate) - Lucas Yamanishi, ADNET Systems

1. STOP WRITING PUPPET MODULES
Best Practices In The Puppet Community
Assembled by Lucas Yamanishi / lucas.yamanishi@nasa.gov

2. http://lucas.yamanishi.us/stop_writing_puppet_modules

3. Bona Fides
Systems Administrator - ADNET Systems, Inc.
NASA SESDA PMO
(Space and Earth Science Analysis Project Management Office)

4. Background in the US Army
Infantry
Counterintelligence (Reserves)

6. Minor contributions made to...
Gentoo
vim-puppet
various Puppet modules
This presentation software ( )reveal-ck

7. DISCLAIMER

8. AGENDA
Intro
Free & Open Source Software
Community Workflows
Building with Community in mind
Finding & building great Puppet modules

9. Stop Writing Puppet Modules
(and start focusing on your business)

10. Puppet is more than a...
configuration tool
framework
language

11. Puppet is a community

12. FREE & OPEN SOURCE SOFTWARE

13. Free as in freedom,
Free as in beer
Open as a book,
Open as in "to everybody"

14. Puppet
Open Source Community

15. Community Benefits
Large ecosystem
Linus's Law (many eyes)
Reduced maintenance costs*
Easier to troubleshoot*
Better overall quality*

18. Hidden Costs
Limited support*
Publication requirements
Legal overhead
No guarantees

19. Open Source Software Policy
(use and contribution)

20. Software Policy
(use and contribution)

21. Software Policy
(use and contribution)
What content is OK? What's off limits?
Who signs off?
Acceptable license features
Use permission
Redistribution rights
Attribution requirements
Patent protection
Disclaimer of liability
Acceptable licenses (MIT, BSD, Apache, GPL, etc.)
Display of license (LICENSE file, file headers, etc.)
Contributor License Agreements (CLAs)
Quality control

22. WORKFLOWS

23. The Puppet Forge
GitHub & Google

24. puppet module install

25. git clone

26. Feature branches
Image courtesy of -
.
Atlassian Creative Commons Attribution 2.5
Australia License

27. r10k
http://github.com/puppetlabs/r10k

28. BUILDING
WITH COMMUNITY IN MIND

29. environment.conf
Puppet >= 3.6 required
Older versions
modulepath = site:modules:$basemodulepath
basemodulepath = $confdir/$environment/site:$confdir/$environment/modules

30. manifests/site.pp
Facter >= 2.2 required for $::os structured facts
$os_name = $::os['name']
$os_major = $::os['release']['major']
$os_minor = $::os['release']['minor']
node default {
$host_group = 'default'
$security_policy = 'high'
include 'base'
warning("Node ${::certname} does not match any host groups")
}
node /^ntp[[:digit:]]{2}.dca.example.net$/ {
$host_group = 'ntp'
$location = 'DCA'
$security_policy = 'medium'
include 'base'
}

31. site/base/manifests/init.pp
Puppet >= 3.0 required
# A base class to manage Puppet runs
class base {
$hiera_classes = hiera_array('classes', [])
include $hiera_classes
}

32. hiera.yaml
Puppet >= 3.0 required
---
:backends:
- 'eyaml'
- 'yaml'
:merge_behavior: 'deeper'
:hierarchy:
- "nodes/%{::clientcert}"
- "host_groups/%{::host_group}"
- "os/%{::kernel}/%{::osfamily}/%{::os_name}/%{::os_major}/%{::os_minor}"
- "os/%{::kernel}/%{::osfamily}/%{::os_name}/%{::os_major}"
- "os/%{::kernel}/%{::osfamily}/%{::os_name}"
- "os/%{::kernel}/%{::osfamily}"
- "os/%{::kernel}"
- "locations/%{::location}"
- "security_policies/%{::security_policy}"
- 'common'
:yaml:
:datadir: "/etc/puppet/environments/%{::environment}/datadir"
:eyaml:
:datadir: "/etc/puppet/environments/%{::environment}/datadir"
:gpg_gnupghome: '/etc/puppet/gpg'
:extension: 'yaml'

34. host_groups/ntp_stratum2.yaml
Hiera >= 1.3 required for hiera() function in data
---
classes:
- 'ntp'
ntp::preferred_servers:
- %{hiera('ntp_local_master', '')}
ntp::servers:
- 0.us.pool.ntp.org
- 1.us.pool.ntp.org
- 2.us.pool.ntp.org
- 3.us.pool.ntp.org

35. Puppetfile
(for use with )
r10k / librarian-puppet file
r10k
####################
# Site-local modules
#
mod 'root_account',
git: 'git@git-server.example.net:puppet/site-local/root_account.git'
mod 'really_awesome_product',
svn: 'https://svn-server.example.net/puppet/site-local/really_awesome_product/trunk',
rev: '539'
####################
# Third-party modules
#
mod 'docker',
git: 'git@git-server.example.net:puppet/third-party/garethr-docker.git',
tag: 'v4.0.2'
# TODO:
# - find an NTP module

37. FINDING & WRITING GREAT MODULES

38. Modularity

39. Types & Providers
./
|
+-- manifests/
|
+-- lib/
|
+-- puppet/
|
+-- provider/
|
+-- type/

40. Compatibility

41. Operating System Portability
Structure
params.pp
Puppet Labs ticket:
Data in modules
PUP-42

42. Cross-module compatibility
conf.d
Augeas resources
concat
Augeas Providers

43. Semantic Versioning
puppetforgepuppetforge v0.9.0v0.9.0
Major
Minor
Bugfix
http://SemVar.org

44. Readability

45. Style Guide
Every major [software] project has its own style guide: a set of conventions
(sometimes arbitrary) about how to write code for that project. It is much
easier to understand a large codebase when all the code in it is in a
consistent style.
google-styleguide
https://docs.puppetlabs.com/guides/style_guide.html

46. puppet-lint
http://puppet-lint.com

47. Documentation

48. Tests
Smoke
Unit
Integration
Acceptance

49. rspec-puppet
coveragecoverage 98%98%
http://rspec-puppet.com
require 'spec_helper'
describe 'example_module' do
context 'on CentOS' do
let(:facts) {{ operatingsystem: 'CentOS' }}
context "example_module class with default parameters" do
let(:params) {{ }}
it { is_expected.to compile.with_all_deps }
it { is_expected.to contain_class('example_module::params') }
it { is_expected.to contain_service('example_module') }
it { is_expected.to contain_file('/path/to/example_file').with_ensure('file') }
end
end
end

51. Vagrant
http://VagrantUp.com

52. Beaker
https://github.com/puppetlabs/beaker

53. Skeletons & Other Standards
https://github.com/garethr/puppet-module-skeleton
StdMod

54. QUESTIONS?

55. © Lucas Yamanishi 2015
RESOURCES
(book in pre-release)
Blogs:
Mailing list:
IRC: on
Beginner's Guide to Modules
PuppetBestPractices.com
The Puppet design philosophy - Brian Anderson
Puppet Best Practices - Chris Barbour
Tim Sharpe
Adrien Thebo
Joe Topjian
Gary Larizza
Planet Puppet
Puppet Labs
puppet-users
#puppet freenode

56. This work is licensed under a
.
Creative Commons Attribution-ShareAlike
4.0 International License