This document provides a guide to Puppet through the use of types. It discusses Dijkstra's view on organizing complexity and NOOPing. It then covers differences between the DSL and RAL approaches, defined types, symmetry between resources and types, and implementing types and providers correctly through examples for trafficserver records and git configurations.

1. Complete Beginners' Guide
to Puppet - Through Types!

2. Guide to Puppet - Through Types!

3. whoami
Igor Galić
igalic (gh/irc)
@hirojin (twitter)

4. whoami

5. how i got here
 ✈ 

6. how i got here
c ... bash ... perl
linux ... make ... ansible
puppet

7. how i got here

8. why this talk exists

9. why this talk exists

10. dijkstra
"The art of programming is the art of organizing complexity,
of mastering multitude and avoiding its bastard chaos as
effectively as possible."

11. dijkstra
"Simplicity is a great virtue but it requires hard work to
achieve it and education to appreciate it. And to make
matters worse: complexity sells better."

12. nooop
include 'ssh'

13. hiera
class { 'ssh':
permit_root_login => false,
}

14. include
include 'ssh'

15. resources
igalic@levix ~ % puppet resource user igalic
user { 'igalic':
ensure => 'present',
comment => 'Igor Galić,,,',
gid => '1000',
groups => ['adm', 'cdrom', 'sudo', 'dip', 'plugdev', 'lpadmin', 'sambashare', '
home => '/home/igalic',
shell => '/bin/zsh',
uid => '1000',
}
igalic@levix ~ %

16. differences
dsl detail types & providers
nope access to the RAL yupp
sub-types
impl diff platforms providers
branching
same/same contract/impl type/provider
"easy" overload $name messy

17. defined type
define trafficserver::config::records (
$changes = [ $title ],
) {
include 'trafficserver'
$configfile = "${::trafficserver::sysconfdir}/records.config"
$lens = 'Trafficserver_records.lns'
$context = "/files${configfile}"
$incl = $configfile
augeas { "${lens}_${title}":
lens => $lens,
context => $context,
incl => $incl,
changes => $changes,
notify => Exec[trafficserver-config-reload],
}
}

18. symmetry
@@trafficserver_record { 'proxy.config.http.server_ports':
changes => '80:ipv4 80:ipv6',
}

19. "simple" type
Puppet::Type.newtype(:trafficserver_record) do
desc 'trafficserver_record is a type to manage records.config entries'
newparam(:record, :namevar => true) do
desc "record entry"
end
newproperty(:value) do
desc "Value of this record"
end
end

20. intermezzo

21. "simple" provider
Puppet::Type.type(:trafficserver_record).provide(:traffic_line) do
desc 'Manage traffic server records.config entries using traffic_line command'
commands :traffic_line => 'traffic_line'
mk_resource_methods
ConfigPattern = 'proxy.(config|local|cluster).*'
def initialize(value={})
super(value)
end
def name=(value)
@property_hash[:name] = value
end
# this method is only called when value isn't insync?
def value=(value)
@property_hash[:name] = resource[:name]

22. intermezzo

23. defined type
define git::config(
$value,
$section = regsubst($name, '^([^.]+).([^.]+)$','1'),
$key = regsubst($name, '^([^.]+).([^.]+)$','2'),
$user = 'root',
) {
exec{"git config --global ${section}.${key} '${value}'":
environment => inline_template('<%= "HOME=" + ENV["HOME"] %>'),
path => ['/usr/bin', '/bin', '/usr/local/bin'],
user => $user,
unless => "git config --global --get ${section}.${key} '${value}'",
}
}

24. implementation (wrong)
exec{"git config --global ${section}.${key} '${value}'":
environment => inline_template('<%= "HOME=" + ENV["HOME"] %>'),
path => ['/usr/bin', '/bin', '/usr/local/bin'],
user => $user,
unless => "git config --global --get ${section}.${key} '${value}'",
}

25. type
Puppet::Type.newtype(:git_config) do
validate do
fail('it is required to pass "value"') if self[:value].nil? || self[:value].em
end
newparam(:name) do
desc "The default namevar"
end
newparam(:user) do
desc "The user for which the config will be set. Default value: root"
defaultto "root"
end
newparam(:section, :namevar => true) do
desc "The configuration section. Example: user."
end
newparam(:key, :namevar => true) do
desc "The configuration key. Example: email."
end

26. implementation (correct)
Puppet::Type.type(:git_config).provide(:git_config) do
mk_resource_methods
def check_current?(value)
require 'etc'
user = @resource[:user]
key = @resource[:key]
section = @resource[:section]
home = Etc.getpwnam(user)[:dir]
current = Puppet::Util::Execution.execute(
"git config --global --get #{section}.#{key}",
:uid => user,
:failonfail => false,
:custom_environment => { 'HOME' => home }
)
return value == current.strip
end
def update

27. done

28. references
puppet types and providers by Dan Bode & Nan Liu
shit gary larizza says, e.g.: http://garylarizza.com/blog/2013
/12/15/seriously-what-is-this-provider-doing/
<3 ADRIEN THEBO <3 Morgan Haskel <3 Ashley Penney </3
Hunter Haugen <3
pry <3
https://github.com/Brainsware/puppet-trafficserver
https://github.com/puppetlabs/puppetlabs-git