PuppetConf 2016: Puppet 4.x: The Low WAT-tage Edition – Nick Fagerlund, Puppet
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The document is a presentation by Nick Fagerlund discussing various aspects of Puppet programming, including concepts like relative namespacing, data type annotations, and syntax errors. It covers examples of common pitfalls in Puppet scripts and demonstrates proper coding practices for better clarity and functionality. The agenda includes addressing fundamental chaos, slapstick moments in coding, and promoting elegance in coding practices.
![Data Type Nonsense
$one = 1
# String
$one_times_one = 1*1
# Fixnum
$an_undef = undef
# NilClass
$multi_undefs = [undef, undef]
# Symbol (:undef)
18](https://image.slidesharecdn.com/puppetconf2016-puppet4lowwat-tage-161102221604/85/PuppetConf-2016-Puppet-4-x-The-Low-WAT-tage-Edition-Nick-Fagerlund-Puppet-18-320.jpg)
![Interpolation Shenanigans
notice("Twenty plus eighty is ${'20' + 80}.")
# Notice: Scope(Class[main]): Twenty plus
eighty is 100.
20](https://image.slidesharecdn.com/puppetconf2016-puppet4lowwat-tage-161102221604/85/PuppetConf-2016-Puppet-4-x-The-Low-WAT-tage-Edition-Nick-Fagerlund-Puppet-20-320.jpg)
![The Great Escape
$s32path = 'C:WindowsSystem32'
notice($s32path)
# Notice: Scope(Class[main]):
C:WindowsSystem32
>:c
25](https://image.slidesharecdn.com/puppetconf2016-puppet4lowwat-tage-161102221604/85/PuppetConf-2016-Puppet-4-x-The-Low-WAT-tage-Edition-Nick-Fagerlund-Puppet-25-320.jpg)
![The Great Escape
$gitconfig = @("GITCONFIG"/L)
[user]
name = ${displayname}
email = ${email}
[alias]
lg = "log —pretty=format:’%C(yellow)%h
%C(reset) %s%C(cyan)%cr%C(reset) %C(blue)%an
%C(reset) %C(green)%d%C(reset)’ --graph"
| GITCONFIG
26](https://image.slidesharecdn.com/puppetconf2016-puppet4lowwat-tage-161102221604/85/PuppetConf-2016-Puppet-4-x-The-Low-WAT-tage-Edition-Nick-Fagerlund-Puppet-26-320.jpg)
![The Great Escape
$s32path = @(MYPATH)
C:WindowsSystem32
-MYPATH
notice($s32path)
# Notice: Scope(Class[main]):
C:WindowsSystem32
27](https://image.slidesharecdn.com/puppetconf2016-puppet4lowwat-tage-161102221604/85/PuppetConf-2016-Puppet-4-x-The-Low-WAT-tage-Edition-Nick-Fagerlund-Puppet-27-320.jpg)
![Class Class
class class {
notify {'hey it worked':}
}
include "class"
# Notice: hey it worked
# Notice: /Stage[main]/Class/Notify[hey it
worked]/message: defined 'message' as 'hey it
worked'
29](https://image.slidesharecdn.com/puppetconf2016-puppet4lowwat-tage-161102221604/85/PuppetConf-2016-Puppet-4-x-The-Low-WAT-tage-Edition-Nick-Fagerlund-Puppet-29-320.jpg)
![Data Type Annotations
class ntp (
$autoupdate = $ntp::params::autoupdate,
$config = $ntp::params::config,
$config_template = $ntp::params::config_template,
$disable_monitor = $ntp::params::disable_monitor,
$driftfile = $ntp::params::driftfile,
$logfile = $ntp::params::logfile,
$iburst_enable = $ntp::params::iburst_enable,
$keys_enable = $ntp::params::keys_enable,
$keys_file = $ntp::params::keys_file,
$keys_controlkey = $ntp::params::keys_controlkey,
$keys_requestkey = $ntp::params::keys_requestkey,
$keys_trusted = $ntp::params::keys_trusted,
$package_ensure = $ntp::params::package_ensure,
$package_name = $ntp::params::package_name,
$panic = $ntp::params::panic,
$preferred_servers = $ntp::params::preferred_servers,
$restrict = $ntp::params::restrict,
$interfaces = $ntp::params::interfaces,
$servers = $ntp::params::servers,
$service_enable = $ntp::params::service_enable,
$service_ensure = $ntp::params::service_ensure,
$service_manage = $ntp::params::service_manage,
$service_name = $ntp::params::service_name,
$udlc = $ntp::params::udlc
) inherits ntp::params {
...
32
...
validate_absolute_path($config)
validate_string($config_template)
validate_bool($disable_monitor)
validate_absolute_path($driftfile)
if $logfile { validate_absolute_path($logfile) }
validate_bool($iburst_enable)
validate_bool($keys_enable)
validate_re($keys_controlkey, ['^d+$', ''])
validate_re($keys_requestkey, ['^d+$', ''])
validate_array($keys_trusted)
validate_string($package_ensure)
validate_array($package_name)
validate_bool($panic)
validate_array($preferred_servers)
validate_array($restrict)
validate_array($interfaces)
validate_array($servers)
validate_bool($service_enable)
validate_string($service_ensure)
validate_bool($service_manage)
validate_string($service_name)
validate_bool($udlc)](https://image.slidesharecdn.com/puppetconf2016-puppet4lowwat-tage-161102221604/85/PuppetConf-2016-Puppet-4-x-The-Low-WAT-tage-Edition-Nick-Fagerlund-Puppet-32-320.jpg)
![Data Type Annotations
class ntp (
Boolean $disable_monitor =
$ntp::params::disable_monitor,
Pattern[/^d+$/] $keys_controlkey =
$ntp::params::keys_controlkey,
Integer $keys_requestkey =
$ntp::params::keys_requestkey,
Array $keys_trusted =
$ntp::params::keys_trusted,
String $package_ensure =
$ntp::params::package_ensure,
34](https://image.slidesharecdn.com/puppetconf2016-puppet4lowwat-tage-161102221604/85/PuppetConf-2016-Puppet-4-x-The-Low-WAT-tage-Edition-Nick-Fagerlund-Puppet-34-320.jpg)
![Iteration
$binaries = ['facter', 'hiera', 'mco', ‘puppet',
'puppetserver']
$binaries.each |String $binary| {
file { "/usr/bin/${binary}":
ensure => link,
target => "/opt/puppetlabs/bin/${binary}",
}
}
37](https://image.slidesharecdn.com/puppetconf2016-puppet4lowwat-tage-161102221604/85/PuppetConf-2016-Puppet-4-x-The-Low-WAT-tage-Edition-Nick-Fagerlund-Puppet-37-320.jpg)
![EPP Templates
<%- | Boolean $keys_enable,
String $keys_file,
Array $keys_trusted,
String $keys_requestkey,
String $keys_controlkey
| -%>
<%# Parameter tag ↑ -%>
<%# Non-printing tag ↓ -%>
<% if $keys_enable { -%>
<%# Expression-printing tag ↓ -%>
keys <%= $keys_file %>
38
<% unless $keys_trusted =~ Array[Data,0,0]
{ -%>
trustedkey <%= $keys_trusted.join(' ') %>
<% } -%>
<% if $keys_requestkey =~ String[1] { -%>
requestkey <%= $keys_requestkey %>
<% } -%>
<% if $keys_controlkey =~ String[1] { -%>
controlkey <%= $keys_controlkey %>
<% } -%>
<% } -%>](https://image.slidesharecdn.com/puppetconf2016-puppet4lowwat-tage-161102221604/85/PuppetConf-2016-Puppet-4-x-The-Low-WAT-tage-Edition-Nick-Fagerlund-Puppet-38-320.jpg)
PuppetConf 2016: Puppet 4.x: The Low WAT-tage Edition – Nick Fagerlund, Puppet
- 1. Puppet 4: The Low WAT-tage Edition Nick Fagerlund, Puppet
- 2. nickf@puppet.com @nfagerlund nfagerlund.net 2 Hi, I’m Nick Fagerlund!!!!
- 3. I’ve seen things you people wouldn’t believe My 2013 talk: https://www.youtube.com/watch?v=aU7vjKYqMUo My much smarter inspiration: https://www.destroyallsoftware.com/talks/wat 3
- 4. Agenda 4
- 5. Agenda 1. Fundamental Chaos 2. Slapstick 3. Elegance 5
- 7. Relative Namespacing class profile::apache { include apache } 7
- 8. Relative Namespacing class profile::apache { class {'apache':} } 8
- 9. Relative Namespacing include apache meant… • <CURRENT NAMESPACE>::apache • <PARENT OF CURRENT NAMESPACE>::apache • etc. and so on • Eventually, ::apache https://projects.puppetlabs.com/issues/2053 https://tickets.puppetlabs.com/browse/PUP-121 9
- 10. Relative Namespacing class profile::apache { include ::apache } 10
- 11. Is Truth Beauty, and Beauty Truth? Facts: architecture => x86_64 domain => local facterversion => 2.4.2 fqdn => "treepie.local" gid => staff hardwareisa => i386 hardwaremodel => x86_64 hostname => treepie 11
- 12. Is Truth Beauty, and Beauty Truth? if $::is_virtual { # do something } 12
- 13. Is Truth Beauty, and Beauty Truth? “false” 13
- 14. Is Truth Beauty, and Beauty Truth? if $::is_virtual == 'true' { ... } # or: if str2bool($::is_virtual) { ... } # with the str2bool() function from puppetlabs/stdlib 14
- 15. Is Truth Beauty, and Beauty Truth? $interfaces = lo0,gif0,stf0,en0,en1,en2,p2p0,awdl0, bridge0,utun0 $macaddress_en0 = 72:00:04:eb:7a:93 ...etc. 15
- 16. 2. Slapstick 16
- 17. Data Type Nonsense $myvar = /^# @.*$/ notice($myvar) # Error: …Syntax error at '/' at /root/test.pp:1 17
- 18. Data Type Nonsense $one = 1 # String $one_times_one = 1*1 # Fixnum $an_undef = undef # NilClass $multi_undefs = [undef, undef] # Symbol (:undef) 18
- 19. Interpolation Shenanigans notice("Twenty plus eighty is ${20 + 80}.") # Error: left operand of + is not a number at /root/test.pp:15 19
- 20. Interpolation Shenanigans notice("Twenty plus eighty is ${'20' + 80}.") # Notice: Scope(Class[main]): Twenty plus eighty is 100. 20
- 21. Interpolation Shenanigans • Single bare word: • ${variable} • Bare word plus chained function call: • ${variable.split(‘,’)} • That’s it. Otherwise it’s an expression. 21
- 22. Inconsistent Comparisons notice( 'eat' == 'EAt' ) # true notice( 'eat' in 'EAten' ) # false 22
- 23. The Great Escape $greeting = 'How's it going?' 23
- 24. The Great Escape $s32path = 'C:WindowsSystem32' notice($s32path) # Error: Unclosed quote after '' in 'C:WindowsSystem32' 24
- 25. The Great Escape $s32path = 'C:WindowsSystem32' notice($s32path) # Notice: Scope(Class[main]): C:WindowsSystem32 >:c 25
- 26. The Great Escape $gitconfig = @("GITCONFIG"/L) [user] name = ${displayname} email = ${email} [alias] lg = "log —pretty=format:’%C(yellow)%h %C(reset) %s%C(cyan)%cr%C(reset) %C(blue)%an %C(reset) %C(green)%d%C(reset)’ --graph" | GITCONFIG 26
- 27. The Great Escape $s32path = @(MYPATH) C:WindowsSystem32 -MYPATH notice($s32path) # Notice: Scope(Class[main]): C:WindowsSystem32 27
- 28. Class Class class class { notify {'hey it worked':} } include class # Error: Syntax error at 'class' at /root/test.pp:5 28
- 29. Class Class class class { notify {'hey it worked':} } include "class" # Notice: hey it worked # Notice: /Stage[main]/Class/Notify[hey it worked]/message: defined 'message' as 'hey it worked' 29
- 30. Class Class class class { notify {'hey it worked':} } include "class" # Error: 'class' is not a valid classname at /Users/nick/Desktop/test.pp:1:7 30
- 31. 3. Elegance 31
- 32. Data Type Annotations class ntp ( $autoupdate = $ntp::params::autoupdate, $config = $ntp::params::config, $config_template = $ntp::params::config_template, $disable_monitor = $ntp::params::disable_monitor, $driftfile = $ntp::params::driftfile, $logfile = $ntp::params::logfile, $iburst_enable = $ntp::params::iburst_enable, $keys_enable = $ntp::params::keys_enable, $keys_file = $ntp::params::keys_file, $keys_controlkey = $ntp::params::keys_controlkey, $keys_requestkey = $ntp::params::keys_requestkey, $keys_trusted = $ntp::params::keys_trusted, $package_ensure = $ntp::params::package_ensure, $package_name = $ntp::params::package_name, $panic = $ntp::params::panic, $preferred_servers = $ntp::params::preferred_servers, $restrict = $ntp::params::restrict, $interfaces = $ntp::params::interfaces, $servers = $ntp::params::servers, $service_enable = $ntp::params::service_enable, $service_ensure = $ntp::params::service_ensure, $service_manage = $ntp::params::service_manage, $service_name = $ntp::params::service_name, $udlc = $ntp::params::udlc ) inherits ntp::params { ... 32 ... validate_absolute_path($config) validate_string($config_template) validate_bool($disable_monitor) validate_absolute_path($driftfile) if $logfile { validate_absolute_path($logfile) } validate_bool($iburst_enable) validate_bool($keys_enable) validate_re($keys_controlkey, ['^d+$', '']) validate_re($keys_requestkey, ['^d+$', '']) validate_array($keys_trusted) validate_string($package_ensure) validate_array($package_name) validate_bool($panic) validate_array($preferred_servers) validate_array($restrict) validate_array($interfaces) validate_array($servers) validate_bool($service_enable) validate_string($service_ensure) validate_bool($service_manage) validate_string($service_name) validate_bool($udlc)
- 33. Data Type Annotations ~~~~ 👀 ZOOM AND ENHANCE 👀 ~~~~ class ntp ( $config_template = $ntp::params::config_template, $disable_monitor = $ntp::params::disable_monitor, ... ) inherits ntp::params { ... validate_string($config_template) validate_bool($disable_monitor) 33
- 34. Data Type Annotations class ntp ( Boolean $disable_monitor = $ntp::params::disable_monitor, Pattern[/^d+$/] $keys_controlkey = $ntp::params::keys_controlkey, Integer $keys_requestkey = $ntp::params::keys_requestkey, Array $keys_trusted = $ntp::params::keys_trusted, String $package_ensure = $ntp::params::package_ensure, 34
- 35. Iteration •Old Ruby DSL? •Do-nothing defined types? •create_resources function? 35
- 36. Data Type Annotations # in Hiera data: admin_users: casey: uid: '1330' gid: allstaff shell: zsh groups: - developers - release leslie: uid: '1308' gid: allstaff groups: - prosvc 36 # in Puppet manifest: class puppet_ops::users::virtual { create_resources( '@user', lookup('admin_users'), { # defaults ensure => present, purge_ssh_keys => true, } ) }
- 37. Iteration $binaries = ['facter', 'hiera', 'mco', ‘puppet', 'puppetserver'] $binaries.each |String $binary| { file { "/usr/bin/${binary}": ensure => link, target => "/opt/puppetlabs/bin/${binary}", } } 37
- 38. EPP Templates <%- | Boolean $keys_enable, String $keys_file, Array $keys_trusted, String $keys_requestkey, String $keys_controlkey | -%> <%# Parameter tag ↑ -%> <%# Non-printing tag ↓ -%> <% if $keys_enable { -%> <%# Expression-printing tag ↓ -%> keys <%= $keys_file %> 38 <% unless $keys_trusted =~ Array[Data,0,0] { -%> trustedkey <%= $keys_trusted.join(' ') %> <% } -%> <% if $keys_requestkey =~ String[1] { -%> requestkey <%= $keys_requestkey %> <% } -%> <% if $keys_controlkey =~ String[1] { -%> controlkey <%= $keys_controlkey %> <% } -%> <% } -%>
- 39. Thanks 39