Here are the slides from Martin Alfke's PuppetConf 2016 presentation called Moving from Exec to Types and Providers. Watch the videos at https://www.youtube.com/playlist?list=PLV86BgbREluVjwwt-9UL8u2Uy8xnzpIqa

1. Moving from Exec to Types and
Providers
This is not a talk, more a story.

2. Moving from Exec to Types and providers - Martin Alfke © example42 GmbH 2016
example42 GmbH - Berlin / Germany
Martin Alfke
CEO & Co-Founder
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3. The Story begins ...
Part #1 - Puppet Module using Exec CLI
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4. Moving from Exec to Types and providers - Martin Alfke © example42 GmbH 2016
Puppet Module for VM management system
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OpenNebula config concept - Image taken from opennebula.org

5. Solution 1 - Exec Resource Type
Run the CLI tools
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6. Moving from Exec to Types and providers - Martin Alfke © example42 GmbH 2016
Exec Resource Type
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7. Moving from Exec to Types and providers - Martin Alfke © example42 GmbH 2016
Exec Resource Type
● one-time commands
● does not deal well with changes
(yes, you can use refreshonly =>
true)
● was only capable of managing
all artefacts of a configuration
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8. Moving from Exec to Types and providers - Martin Alfke © example42 GmbH 2016
Exec Resource Type
● root Shell with empty
environment
● “Emergency Exit” (Luke
Kanies - Berlin - Q4/2015)
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9. Moving from Exec to Types and providers - Martin Alfke © example42 GmbH 2016
Exec Resource Type
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10. The Story continues ...
Part #2 - Puppet Module using Defined Resource Types
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11. Solution 2 - Defined Resource Type
File - Service Pattern
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12. Moving from Exec to Types and providers - Martin Alfke © example42 GmbH 2016
Defined Resource Type
● (Package) - File - Service
pattern
● self defined resource type as
wrapper
● config artefact per title (data
from hash)
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13. Moving from Exec to Types and providers - Martin Alfke © example42 GmbH 2016
Defined Resource Type
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14. Moving from Exec to Types and providers - Martin Alfke © example42 GmbH 2016
Defined Resource Type
● Service Resource
● Always check hasrestart, hasstatus options
● Possibility to manage individual config artefacts
● Difficulty when changing parameters of an existing config
artefact -> restart = stop, start
● Wrapper shell script -> Exec replacement
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15. The Story continues ...
Part #3 - Puppet Module using Custom Resource Types
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16. Solution 3 - Custom Resource Type
Idempotent, non-breaking, prefetch capable configuration
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17. Moving from Exec to Types and providers - Martin Alfke © example42 GmbH 2016
Custom Resource Type
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18. Moving from Exec to Types and providers - Martin Alfke © example42 GmbH 2016
Custom Resource Type
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19. Types and Providers
Basic concept
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20. Moving from Exec to Types and providers - Martin Alfke © example42 GmbH 2016
Types and Providers
● Are CLI tools / API’s available
?
● Can output be rendered in
structured data ?
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21. Types
Describe Puppet DSL Syntax
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22. Moving from Exec to Types and providers - Martin Alfke © example42 GmbH 2016
Type - Beginning
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<module>/lib/puppet/type/my_file.rb

23. Moving from Exec to Types and providers - Martin Alfke © example42 GmbH 2016
Type - Properties and Parameters
● Properties
● everything you can set or modify (e.g. UID)
● Parameters
● change the way how the provider works (e.g. managehome)
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24. Moving from Exec to Types and providers - Martin Alfke © example42 GmbH 2016
Type - Properties and Parameters
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25. Moving from Exec to Types and providers - Martin Alfke © example42 GmbH 2016
Type - DSL
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26. Providers
Command Logic
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27. Moving from Exec to Types and providers - Martin Alfke © example42 GmbH 2016
Provider - Beginning
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<module>/lib/puppet/provider/my_file/ruby.rb

28. Moving from Exec to Types and providers - Martin Alfke © example42 GmbH 2016
Provider - Running commands
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29. Moving from Exec to Types and providers - Martin Alfke © example42 GmbH 2016
Provider - Properties and Parameters
● Getter
● read the existing state of an attribute
● Setter
● set the desired state of an attribute
● Idempotency
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30. Moving from Exec to Types and providers - Martin Alfke © example42 GmbH 2016
Provider - Getters and Setters
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31. Moving from Exec to Types and providers - Martin Alfke © example42 GmbH 2016
Provider - Create and Destroy
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32. Types and Providers
Part #4 - Do’s and don’t’s
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33. Dont’s
What you don’t want to do - please.
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34. Moving from Exec to Types and providers - Martin Alfke © example42 GmbH 2016
Types and Providers
● exec in custom Providers
● running %x(...) or exec(...)
● use of restricted words
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35. Do
What you want to do.
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36. Moving from Exec to Types and providers - Martin Alfke © example42 GmbH 2016
Types and Providers
● one type
● one or more providers
● What do you want to manage?
● What may be changed ?
● What can be set on creation only ?
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37. Moving from Exec to Types and providers - Martin Alfke © example42 GmbH 2016
Types and Providers
● Multiple providers will allow you
to react on
● New SW version with new CLI
format or new commands
● Different SW usage on
different OS
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38. Why Types and Providers
Manage an Enterprise Application
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39. Moving from Exec to Types and providers - Martin Alfke © example42 GmbH 2016
Types and Providers
● Vendor forbids to edit config
files
● Vendor insists in using CLI tools
● e.g. IBM WebSphere
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40. Moving from Exec to Types and providers - Martin Alfke © example42 GmbH 2016
Dear Enterprise Software producers
● give us code for our CfgMgmt
tool
● we want one tool to manage
everything
● we want to still have your
support for your software
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41. Types and Providers
Part #5 - How to start
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42. Ruby
Version and Tools
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43. Moving from Exec to Types and providers - Martin Alfke © example42 GmbH 2016
Ruby - Version and Tools
● Don’t mess your system Ruby
● RVM / rbenv
● Gems
● bundler
● wirble
● pry
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44. Moving from Exec to Types and providers - Martin Alfke © example42 GmbH 2016
Ruby - ~/.irbrc
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45. Types & Providers
Implementation Examples
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46. Moving from Exec to Types and providers - Martin Alfke © example42 GmbH 2016
Types & Providers - Examples
● Books
● https://www.amazon.com/Puppet-Types-Providers-Dan-Bode/
dp/1449339328
● Blogs
● http://garylarizza.com/blog/2013/11/25/fun-with-providers/
● https://www.enterprisemodules.com/blog/2014/01/puppet-
custom-types-the-easy-way/
● http://www.datacentred.co.uk/blog/puppet-custom-types/
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47. Moving from Exec to Types and providers - Martin Alfke © example42 GmbH 2016
Types & Providers - Examples
● Docs
● https://docs.puppet.com/guides/custom_types.html
● https://docs.puppet.com/guides/provider_development.html
● https://docs.puppet.com/puppet/latest/reference/
lang_reserved.html
● Talks
● http://www.slideshare.net/TimCinel/writing-custom-puppet-
types-and-providers-to-manage-webbased-applications
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48. Types and Providers
Part #6 - Summary
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49. Moving from Exec to Types and providers - Martin Alfke © example42 GmbH 2016
Moving from Exec to Types and Providers - Summary
● Exec is for one time commands only -
it is an emergency exit
● Types and Providers are not difficult
● Types have the Puppet DSL syntax,
Providers have Logic and Commands
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50. Moving from Exec to Types and providers - Martin Alfke © example42 GmbH 2016
Moving from Exec to Types and Providers - Summary
● Ruby is easy to learn
● Start with IRB + Wirble
● Use Pry Gem for debugging
● Start doing configuration the right way
● Use Puppet’s power for Extensions
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