"We want to automate this application rollout and configuration by using Puppet DSL." The task is clear, the tool is clear. But how to proceed? Installation is delivered as tarball, configuration is done by running cli commands. This talk will give an overview on how we started using commands within exec resources, the difficulties and problems that rose up, and the process of moving to Types and Providers.

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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