The document discusses new features and changes in Puppet 4, including Puppet Server running on JVM, packaging improvements, environment configuration options, language features like lambdas and HEREDOC support, type validation, and deprecations like node inheritance and hyphens in names. It highlights four key powers of Puppet 4: performance, scalability, measurability, and flexibility in dealing with complex data types natively. Upgrading to Puppet 4 requires changes to comply with deprecations and testing to ensure compatibility.

1. Text
The Power of Puppet 4
Martin Alfke
ma@example42.com

2. About me
PL Training Partner
Module Contributor
Automation Enthusiast

3. Puppet Server &
Packaging
Environments
New language features

4. Types, Types, Types
Deprecations
The 4 Powers of Puppet
4

5. Puppet Server & Packages

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

7. Puppet Packaging
AIO - like PE
New package name
Discussion on mailinglist

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. HEREDOC syntax check
@(EOF:json)
Can be used by e.g. Gepetto or any other Puppet
plugin
Built in : json
$var = @(EOF:json)
{
“Puppet”: ‘awesome’
}
- EOF

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?
!
!
!
!
!
!
Missing quotes
String instead of bool
!
Missing quotes and leading 0
Missing trailing slash
String instead of bool

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

28. 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.

29. 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],
) {
}

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

31. Deprecations

32. Deprecations
Node inheritance
Empty string comparison
Variable naming
Reference syntax
Hyphens in names
Ruby DSL

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. 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

39. Reference syntax
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

50. More information
https://docs.puppetlabs.com/puppet/3.7/reference/
deprecated_language.html
http://puppet-on-the-edge.blogspot.de/
https://github.com/puppetlabs/puppet-specifications

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

52. Thank you
Martin Alfke
!
Co-Founder & CEO
example42 GmbH i.G.