Cookbook Reusability

Chef Summit 2014

Transcript

1. Cookbook Reusability!
   Chef Community Summit
   2014
   

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2. Sean OMeara!
   someara@getchef.com!
   @someara
   

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3. whoami
   

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4. A Year in Review
   

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5. Diversification
   

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6. 7zip!
   apache2!
   ark!
   application*!
   couchdb!
   Imagemagick!
   java
   

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7. logrotate!
   mercurial!
   munin!
   nagios!
   nginx!
   ntp!
   openvpn
   

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8. pacman!
   postgresql!
   python!
   reprepro!
   rabbitmq!
   runit!
   supervisor
   

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9. selinux!
   tmux!
   varnish !
   wordpress!
   

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10. Supermarket
    https://www.flickr.com/photos/mobilestreetlife/10885044043
    

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11. • Escaped the tyranny of JIRA!
    • Moved to Github Issues!
    • Automated CLA checking!
    • OSS Artifact Repository
    

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12. Rewrites
    

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13. 2009
    0.5.2
    Chef
    Vagrant
    ChefSpec
    0.1.0
    0.0.2
    Minitest-Chef
    Berkshelf
    Test Kitchen
    2010
    0.9.0
    2011
    0.10.0
    2012
    10.12.0
    1.0.0
    0.2.0
    1.0.0
    0.7.0
    1.0.0
    2013 2014
    1.0.0
    2.0.0
    1.0.0
    2.0.0
    1.4.0
    11.0.0 12.0.0
    1.6.5
    3.0.0
    3.0.0
    1.2.2
    ServerSpec
    ChefDK
    0.0.1 2.0.0
    0.2.2
    TDI Capability
    0.8.0
    

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14. yum!
    yum-*!
    jenkins!
    mysql!
    httpd
    

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15. The Evolution of a Chef
    Cookbook
    

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16. Stage 1 - Paradise
    https://www.flickr.com/photos/nattu/1385100375/
    

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18. test / repair
    test / repair
    test / repair
    

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19. Easy to read
    
    Easy to grok
    
    Easy to test
    }
    

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20. Stage 2 - if statements
    

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21. logic
    compiled into
    resource collection
    

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22. Resource
    DSL
    }
    Just
    Ruby
    }
    

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23. Resource
    DSL
    }
    Just
    Ruby
    } }Chef
    

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24. Stage 3 - Crazytown
    https://www.flickr.com/photos/kwl/4595324641
    

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26. wat
    

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27. Why?
    

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28. Reusable is useful
    

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29. Cross-platform is useful
    

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30. We desire useful things
    

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31. Platform idioms are hard
    

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32. Keeping the Dream Alive
    https://www.flickr.com/photos/kalexanderson/7014655351/
    

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33. Most people just write their
    own cookbooks from
    scratch
    

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34. I really really really want
    reusable cross-platform
    cookbooks
    

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35. Lessons Learned
    

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36. Attributes are routinely
    abused
    https://www.flickr.com/photos/jabberwocky381/2828863789
    

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38. Attributes are an
    interface
    

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39. Attributes are tunable
    knobs
    

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41. You probably just want a
    variable
    

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43. Or even a method
    

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45. Using an attribute to track
    state during a Chef run
    causes tears and sorrow
    

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46. Prefer resource parameters
    

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49. Primitives are more useful
    than opinionated policy
    

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50. “They’re Just Resources”!
    !
    LWRP is Googleable
    

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51. Zoom out a level!
    !
    Think about services and
    runtimes, not files and processes
    

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52. Singleton resources are good but
    confusing. Possibly even
    dangerous.!
    !
    Multiple instance support is better!
    !
    Cross-platform resources are best
    

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54. BDD / TDD yields high
    quality cookbooks
    https://www.flickr.com/photos/glenirah/4376553184
    

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55. Test Kitchen!
    ServerSpec / Minitest / Bats!
    ChefSpec
    

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56. 2009
    0.5.2
    Chef
    Vagrant
    ChefSpec
    0.1.0
    0.0.2
    Minitest-Chef
    Berkshelf
    Test Kitchen
    2010
    0.9.0
    2011
    0.10.0
    2012
    10.12.0
    1.0.0
    0.2.0
    1.0.0
    0.7.0
    1.0.0
    2013 2014
    1.0.0
    2.0.0
    1.0.0
    2.0.0
    1.4.0
    11.0.0 12.0.0
    1.6.5
    3.0.0
    3.0.0
    1.2.2
    ServerSpec
    ChefDK
    0.0.1 2.0.0
    0.2.2
    This Slide Again
    0.8.0
    

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57. Full test coverage is tedious
    

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58. Full test coverage is totally
    worth it
    

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59. Let users bring their own
    configurations
    

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60. It is better to add to a
    resource_collection than to
    monkey patch it
    

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61. Configuration files are the
    brains of a service
    

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62. Manage minimal
    configuration to get a service
    running
    

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63. Offload further configuration
    to the user
    

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64. conf.d is your friend
    

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65. Hide everything else
    inside a resource
    

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66. Add resource parameters
    when appropriate
    

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69. Cross-platform cookbooks
    are hard
    https://www.flickr.com/photos/glenirah/4376553184
    

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70. Cross-platform resources
    are even harder
    

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71. They can be done!
    

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72. Create a resource
    

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74. Create a provider
    

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76. Subclass platform providers
    

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82. Set provider default for
    platforms
    

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84. Do Repeat Yourself
    

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85. Some resources are often
    the duplicated across
    providers
    

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86. That’s fine. It’s the pattern
    as a whole that’s important
    

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87. Maximize for grokability
    

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88. People will be reading your
    code for the first time
    during operations work
    

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89. Init systems are annoying
    

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90. Using a service resource
    usually requires file or
    template resources in
    addition to
    service[thingd]
    

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91. Debconf!
    Docker!
    LaunchD!
    Runit!
    SMF!
    Simple!
    SystemD!
    Sysvinit!
    Upstart!
    Windows Services
    

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92. Subclassing is awesome
    

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94. Customize before recipe
    compilation
    

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95. Going Forward
    

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96. Cookbooks that ship
    resource primitives
    

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97. More examples to copy
    

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98. More breaking backwards
    compatibility (sorry)
    

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99. Providers implemented
    with Docker containers
    (why not?)
    

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100. chef-metal
     

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101. Tell me what you think
     

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102. Please don’t hurt me =)
     

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