Puppet 4 introduces significant changes including improved performance, scalability, measurability and flexibility. It features a new Puppet Server and packaging, enhanced environments, r10k for managing environments from git, new language features like lambdas and EPP templating, stronger data typing, and deprecation of features like node inheritance. Upgrading requires testing and supporting modules for compatibility with the breaking changes in Puppet 4.

1. Text
The Power of Puppet 4
Martin Alfke
ma@example42.com
Image: http://praetoris01.deviantart.com/

2. Martin Alfke
PL Training Partner
Module Contributor
!
Freelancer / example42
Infrastructure Architect

3. Welcome Puppet 4
April 15th 2015
https://puppetlabs.com/
blog/say-hello-open-
source-puppet-4
http://
docs.puppetlabs.com/
puppet/4.0/reference/
index.html

4. Puppet Anniversary
founded in 2005

5. Puppet Server & Packages

6. Puppet Server on JVM
Clojure
Trapperkeeper
JMX & internal metrics
(PE only)

7. Puppet Packaging
AIO - like PE
New package name
New repository layout
No automatic update

8. Environments

9. Config environments
Static puppet.conf
[production]
modulepath = /etc/puppet/production/modules
manifests = /etc/puppet/production/manifests/site.pp
!
[test]
modulepath = /etc/puppet/test/modules
manifests = /etc/puppet/test/manifests/site.pp

10. Config environments
Dynamic puppet.conf
[master]
modulepath = /etc/puppet/$environment/modules
manifests = /etc/puppet/$environment/manifests/site.pp
!

11. Directory environments
puppet.conf
[master]
environmentpath = /etc/puppet/environments
!
File system
/etc/puppet/environments/
production/
modules/
manifests/
environment.conf
test/
modules/
manifests/
Directory

12. Benefits
All environments in one place
Per environment configuration (environment.conf)
config_version = '/usr/bin/git --git-dir /etc/puppet/environments/
$environment/.git rev-parse HEAD'
Newly added environments are available immediately

13. r10k
Robot 10000
Manage environment in git branches
Puppetfile handles modules and versions

14. New language features

15. Lambdas
Lambda
“a block of code that has parameters and can be invoked/called with arguments. A
single lambda can be passed to a function”
$a = [1,2,3]
each($a) |value| {notice $value }

16. Lambdas and functions
each - iterating over an array
map - transform an array or hash into a new array
filter - filters an array or hash
reduce - reduces an array or hash to a single value
slice - slices an array or hash into chunks

17. Using functions
Standard Puppet way:
function_name(argument) - each($variable)
Ruby way - chaining
argument.function_name - $variable.each

18. EPP Template engine
Use Puppet $var instead of Ruby @var
epp(filename)
inline_epp(epp_string)

19. HEREDOC support
Like Shell HEREDOC
$multiline_text = @(EOF)
# Managed by Puppet
intended two spaces
starting at beginning of line
| intention starts at pipe sign
EOF

20. HEREDOC control character
- prevents a new line (like erb/epp)
@(“EOF”) - variable substition
@(EOF/tn) - enables char escapes
availabe char escapes: t,s,r,n,u,L,$
Default to off

21. Puppet 4.0 Data Bindings
New “hierarchy”:
global data (hiera)
data in environment (environment.conf)
data in modules

22. Types, Types, Types

23. Why do we need types?
class ssh (
$server = true,
) {
if $server {
include ssh::server
}
}
Parameterized class with parameter default

24. Why do we need types?
class ssh (
$server = true,
) {
if $server {
include ssh::server
}
}
!
!
class { ‘ssh’:
server => ‘false’,
}
!
!
!
!
!
!
!
!
!
Usage of parameterised class. But: string
instead of boolean !

25. Why do we need types?
class ssh (
$server = true,
) {
if validate_bool($server) {
include ssh::server
}
}
!
!
class { ‘ssh’:
server => ‘false’,
}
Parameterized class with parameter default
!
!
Now with data validation (from stdlib)

26. Why do we need types?
users::hash:
‘tom’:
gid: ‘123’
home: ‘/home/tom’
managehome: false
‘ben’:
gid: ‘124’
home: /home/ben
managehome: ‘true’
‘tim’:
gid: 0125
home: ‘home/tim’
managehome: ‘false’
But: how to deal with more complex data?
!
!
Do you see the errors?

27. Why do we need types?
users::hash:
‘tom’:
gid: ‘123’
home: ‘/home/tom’
managehome: false
‘ben’:
gid: ‘124’
home: /home/ben
managehome: ‘true’
‘tim’:
gid: 0125
home: ‘home/tim’
managehome: ‘false’
But: how to deal with more complex data?
!
!
!
!
!
!
Missing quotes
String instead of bool
!
Missing quotes and leading 0
Missing trailing slash
String instead of bool

28. We need types!
class ssh (
Boolean $server = true,
) {
if $server {
include ssh::server
}
}
!
Types, Types, Types, Types

29. We need types!
class ssh (
Boolean $server = true,
) {
if $server {
include ssh::server
}
}
!
!
class { ‘ssh’:
server => ‘false’,
}
!
Error 400 on SERVER: Expected parameter 'server' of
'Class[Ssh]' to have type Boolean, got String
!
!
!
!
!
!
!
!
!
We now get proper error messages.

30. We want types!
class users (
Hash $hash
) {
$userarray = keys($hash)
users::user_data { $userarray: }
}
!
define users::user_data (
String $gid = $users::hash[$title][gid],
String $home = $users::hash[$title][home],
Boolean $managehome = $users::hash[$title][managehome],
) {
}

31. Available Types
Integer[from, to]
Float[from,to]
Enum[*strings]
Pattern[*patterns]
Regexp[regexp]
Boolean
Array
Hash

32. Deprecations

33. Node Inheritance
node ‘basenode’ {
include base
include security
}
!
node ‘www.server.com’ inherits basenode {
include webserver
}
# Dummy node as default
!
!
!
!
# Real node inherits from basenode

34. Roles & Profiles
node ‘www.server.com’ {
include webserver
}
!
!
class basenode {
include base
include security
}
!
class webserver {
include basenode
}
# No more node inheritance
!
!
!
!
# Define a class instead

35. Empty string comparison
An empty string compares to true instead of false

36. Empty string comparison
$message = ‘’
!
if $message {
notify { “Message: ${message}”: }
}
Empty string set as default
!
Check for variable existing and having
content

37. Empty string comparison
$message = ‘’
!
if $message and $message != ‘’ {
notify { “Message: ${message}”: }
}
Empty string set as default
!
Check for variable existing and not empty
string

38. Variable naming
A variable may not start with
a capital letter
an underscore (well. yes. it may. but. it’s private.)

39. Reference Naming
Reference deprecation
capital letter on title
empty space between Type reference and title
!
Class [Ssh]
!
Class [‘ssh’]
!
Class[‘ssh’]
!
Deprecated capital title
!
Empty space
!
Working

40. Hyphens in names
No more hyphens in
module name
class name
define name

41. Hyphens in names
!
<modulepath>/syslog-ng/
!
<modulepath>/syslog_ng
!
class syslog-ng { … }
!
class syslog_ng { … }
!
Deprecated
!
New name required
!
Deprecated
!
New name required (obious -> module/
class naming convention)

42. Ruby DSL
Puppet Ticket #18876
Closed 02/04/2013
New Ruby DSL API was revamped: “the number and
severity of issues that came up in exploratory testing
led us to the conclusion that it was not supportable
code” - Puppet Dev ML - 01/26/2013
hostclass ‘ssh’ do
end

43. More deprecation
Relative resolution of class names - the reason why
you want to use double colon - include ::ssh
Importing manifests
Matching numbers with regexp
Search function
Mutating arrays and hashes

44. The 4 Powers of Puppet 4

45. Performance
Request response times and catalog compile times
!
!

46. Scalability
Switch on/off functionality for multi master setup
!
!
!

47. Measurability

48. Flexibility
Dealing with complex data natively in Puppet DSL

49. Upgrading to Puppet 4
Breaks old style Puppet
DSL code
Read documentation
carefully
Run tests
Proposed way: new
master

50. Text
Support your modules
Write PR, file bug reports, fix issues

51. More information
http://puppet-on-the-edge.blogspot.com/
https://github.com/puppetlabs/puppet-specification
http://camptocamp.com/actualite/getting-code-ready-
puppet-4/

52. More information
https://docs.puppetlabs.com/puppet/3.7/reference/
deprecated_language.html
http://docs.puppetlabs.com/puppet/4.0/reference/
index.html
https://puppetlabs.com/blog/welcome-puppet-
collections

53. Text
The Power of Puppet 4
Martin Alfke
ma@example42.com
Image: http://praetoris01.deviantart.com/