"Writing and Publishing Puppet Modules" by Colleen Murphy, of Portland State University at Puppet Camp Portland 2014.

1. Writing and Publishing
Puppet Modules
Colleen Murphy, Portland State University
freenode: crinkle
github: cmurphy

2. Hello
This is a beginner’s approach.
This is an outsider’s approach.

3. Hello
PSU’s College of Engineering’s IT department,
aka The Computer Action Team (TheCAT),
uses puppet to manage a diverse infrastructure.
http://github.com/pdxcat

4. What is a puppet module?
● An encapsulation of configuration for a
service
● A structure containing an organized set of
puppet code and data
● Analogous to a package, gem, python library
● The place where your code goes

5. What should a module do?
● Set up a service, such as:
○ ssh
○ mysql
○ apache
○ sudo
● Extend puppet functionality. Examples:
○ puppetlabs/stdl ib
○ puppetlabs/concat

6. The strategy
Set up the service…
without puppet.
Then iterate.

7. Layout of a module
yourmodule/
➔
➔
➔
➔
➔
➔
manifests/
files/
templates/
lib/
|
tests/
spec/
#
#
#
#
where your puppet code goes
flat configuration files
dynamic configuration files
plugins: types and providers, functions,
facts, etc
# example usage, smoke tests
# automated tests

8. Layout of a module
yourmodule/
➔
➔
➔
➔
➔
➔
manifests/
files/
templates/
lib/
|
tests/
spec/
#
#
#
#
where your puppet code goes
flat configuration files
dynamic configuration files
plugins: types and providers, functions,
facts, etc
# example usage, smoke tests
# automated tests

9. Starting out
# puppet module generate cmurphy-ssh
Generating module at /etc/puppet/modules/cmurphy-ssh
cmurphy-ssh
cmurphy-ssh/manifests
cmurphy-ssh/manifests/init.pp
cmurphy-ssh/spec
cmurphy-ssh/spec/spec_helper.rb
cmurphy-ssh/tests
cmurphy-ssh/tests/init.pp
cmurphy-ssh/README
cmurphy-ssh/Modulefile

10. Writing your first module
class ssh {
package { 'openssh-server':
ensure => installed,
}
file { '/etc/ssh/sshd_config':
source =>
"puppet:///modules/ssh/sshd_config",
require => Package['openssh-server'],
}
service { 'ssh':
ensure
=> running,
enable
=> true,
subscribe =>
File['/etc/ssh/sshd_config'],
}
}
node default {
include ssh
}

11. Drop in a configuration file
# Managed by Puppet
# What ports, IPs and protocols we listen for
Port 22
Protocol 2
# Logging
SyslogFacility AUTH
LogLevel INFO
# Authentication:
LoginGraceTime 120
PermitRootLogin no
StrictModes yes
...

12. Needs more portability!
No one should have to change your code or
your files in order to use your module.

13. Update your module
# Managed by Puppet
# What ports, IPs and protocols we listen for
Port <%= @port %>
Protocol 2
# Logging
SyslogFacility <%= @syslog_facility %>
LogLevel <%= @log_level %>
# Authentication:
LoginGraceTime 120
PermitRootLogin <%= @permit_root_login %>
StrictModes yes
...

14. Update your module
class ssh (
$port
= 22,
$syslog_facility
= 'AUTH',
$log_level
= 'INFO',
$permit_root_login = 'no',
) {
...
file { '/etc/ssh/sshd_config':
content =>
template('ssh/sshd_config.erb'),
require => Package['openssh-server'],
}
...
node default {
class { 'ssh':
permit_root_login => 'yes',
}
}

15. Beyond templates
Working with tricky configuration files
● Take advantage of Include conf/* directives
file { 'conf_file':
ensure => present,
content => 'Include "conf.d/*.conf"n',
}
…
define collectd::plugins::exec {
file { "${name}.load":
path => "${conf_dir}/${name}.conf",
content => template('collectd/exec.conf.erb'),
}
}

16. Beyond templates
● puppetlabs/concat
concat { '/etc/motd': }
concat::fragment { 'welcome':
target
=> '/etc/motd',
content => 'Welcome to Redhat',
order
=> '01',
}
concat::fragment { 'legal':
…
}

17. Beyond templates
● puppetlabs/inifile
ini_setting { 'puppetdbserver':
ensure
=> present,
section => 'main',
path
=> "${puppet_confdir}/puppetdb.conf",
setting => 'server',
value
=> $server,
}
ini_setting { 'puppetdbport':
…
}

18. Parameterize your module
class ssh::params {
case $::osfamily {
'Debian': {
$ssh_svc = 'ssh'
class ssh (
...
) {
include ssh::params
}
'Redhat': {
$ssh_svc = 'sshd'
}
default: {
fail("${::osfamily} is not
supported.")
}
}
}
service { $ssh::params::ssh_svc:
ensure => running,
enable => true,
}
...

19. The Forge

20. Publishing your module
Modulefile
name
'cmurphy-ssh'
version '0.0.1'
source 'https://github.com/cmurphy/puppet-module-ssh.git'
author 'Colleen Murphy'
license 'Apache License, Version 2.0'
summary 'Puppet module for ssh'
description 'Demonstration of parameterized ssh module'
project_page 'https://github.com/cmurphy/puppet-module-ssh'
## Add dependencies, if any:
# dependency 'username/name', '>= 1.2.0'

21. Publishing your module
README
●
docs.puppetlabs.com/puppet/3/reference/READMEtemplate.markdown
license
●
choosealicense.com

22. Publishing your module
Changelog
## 2013-12-05 Release 0.10.0
### Summary:
This release adds FreeBSD osfamily support and various other improvements to some
mods.
### Features:
- Add suPHP_UserGroup directive to directory context
- Add support for ScriptAliasMatch directives
...
## 2013-09-06 Release 0.9.0
### Summary:
...

23. Publishing your module
Use semantic versioning!
semver.org
Major.Minor.Patch

24. Publishing your module
$ cd ssh/
$ puppet module build .
$ ls pkg/
cmurphy-ssh-0.0.1 cmurphy-ssh-0.0.1.
tar.gz

25. Testing your module
Add tests
● rspec-puppet
○ rspec-puppet.com
● rspec-system
○ github.com/puppetlabs/rspec-system

26. Maintaining your module
Update your code
● fix bugs
● add features
● manage pull requests

27. Installing modules
Search for modules on forge.puppetlabs.com or
puppet module search
Then install with
puppet module install

28. Thanks!
Learn more at
docs.puppetlabs.com/guides/module_guides/bgtm.html
Colleen Murphy
freenode: crinkle
github: cmurphy