PUP201: How To Use Puppet Like An Adult

Puppet is an immensely powerful tool for system administration, but with great power comes great responsibility, and it’s not always obvious how to structure your configurations. There are many different ways to accomplish similar goals, and this malleability has given rise to a plethora of different design and architecture principles - some of which are good, and many of which are bad.

In this talk, Ben and Dan will explain the guiding principles of responsible Puppet design and architecture, walking you through real-world examples in order to illustrate solid methodological approaches, and illuminate Puppet administrators of all skill levels. As an added bonus, we will also show you how Puppet can be integrated into automated deployment and continuous integration platforms - an increasingly important component of today’s development and operational landscape.

Transcript

1. HOW TO USE PUPPET LIKE AN ADULT A.K.A. PUP201
2. BEN KERO & DANIEL MAHER MOZILLA IT/OPS
3. IT AT MOZILLA
5. PUPPET AT MOZILLA
7. DATA ∉ LOGIC No business data in modules Business logic is totally fine External sources
8. DATA SOURCES Hiera PuppetDB
9. HIERA Lightweight Pluggable Hierarchical Database Many possible back-ends Standard in Puppet 3.0 $ v a r = l o o k u p ( ' s o m e t h i n g ' ) # u n s c o p e d ( c o m p l i c a t e d ) $ v a r = l o o k u p ( ' n a m e s p a c e : : s o m e t h i n g ' ) # s c o p e d ( k i t t e n s )
10. PUPPETDB « High-performance storeconfigs » c l a s s s s h { @ @ s s h { $ h o s t n a m e : t y p e = > d s a , k e y = $ s s h d s a k e y } # D e c l a r e S s h k e y < < | | > > # C o l l e c t }
11. WHERE TO FIND PRE- BUILT MODULES GitHub Puppet Forge
12. IS THAT MODULE RIGHT FOR ME? Distro, flavour, or even OS Complexity Popularity
13. INTERESTING PRE- BUILT MODULES puppetlabs/ntp puppetlabs/cloud_provisioner
14. ROLL YOUR OWN MODULES Generic Parameterised Documented
15. MODULE TEMPLATE $ p u p p e t m o d u l e g e n e r a t e a u t h o r - m o d _ n a m e G e n e r a t i n g m o d u l e a t a u t h o r - m o d _ n a m e / a u t h o r - m o d _ n a m e a u t h o r - m o d _ n a m e / t e s t s a u t h o r - m o d _ n a m e / t e s t s / i n i t . p p a u t h o r - m o d _ n a m e / s p e c a u t h o r - m o d _ n a m e / s p e c / s p e c _ h e l p e r . r b a u t h o r - m o d _ n a m e / R E A D M E a u t h o r - m o d _ n a m e / M o d u l e f i l e a u t h o r - m o d _ n a m e / m a n i f e s t s a u t h o r - m o d _ n a m e / m a n i f e s t s / i n i t . p p
16. CENTRALISED PARAMETERS p a r a m s . p p Basic set of sane platform defaults Highly portable
17. PARAMETERISED CLASSES Similar to definitions c l a s s s o m e d a e m o n ( $ d i r , $ c o n f i g , $ e n s u r e = t r u e ) { f i l e { " $ { d i r } / c o n f i g " : c o n t e n t = > $ c o n f i g } s e r v i c e { ' s o m e d a e m o n ' : e n s u r e = > $ e n s u r e } }
18. SYNTAX & STYLE Style guide Any style - just pick one
19. PARSER VALIDATION $ p u p p e t p a r s e r v a l i d a t e m a n i f e s t . p p e r r : C o u l d n o t p a r s e f o r e n v i r o n m e n t p r o d u c t i o n : S y n t a x e r r o r a t ' b l a h ' a t m a n i f e s t . p p : 8
20. LINTING $ p u p p e t - l i n t m a n i f e s t . p p W A R N I N G : c l a s s n o t d o c u m e n t e d o n l i n e 8 W A R N I N G : l i n e h a s m o r e t h a n 8 0 c h a r a c t e r s o n l i n e 4 4 W A R N I N G : s t r i n g c o n t a i n i n g o n l y a v a r i a b l e o n l i n e 5 4 W A R N I N G : t o p - s c o p e v a r i a b l e b e i n g u s e d w i t h o u t a n e x p l i c i t n a m e s p a c e o n l i n e 5 4
21. PUPPET-CONCAT Dynamically build text files c o n c a t { ' c o n f i g _ f i l e ' : } c o n c a t : : f r a g m e n t { ' h e a d e r ' : t a r g e t = > ' c o n f i g _ f i l e ' , s o u r c e = > ' p u p p e t : / / / m o d u l e s / f o o / h e a d e r . s n i p p e t ' , o r d e r = > 1 0 } c o n c a t : : f r a g m e n t { ' b o d y ' : t a r g e t = > ' c o n f i g _ f i l e ' , c o n t e n t = > t e m p l a t e ( ' f o o / c o n f i g . e r b ' ) , o r d e r = > 2 0 }
22. STDLIB Standard library (widely used) Curated by Puppet Labs Full of useful elements; increasingly necessary
23. SANITY PRESERVATION Default values Verify content Mutually exclusive declarations
24. USEFUL LOG OUTPUT Functions for each log level n o t i c e ( ) ; w a r n ( ) ; e r r ( ) ; Informative & human-readable
25. PUPPET AS A SOURCE OF TRUTH Puppet "ecosystem" Puppet Data Library (PDL)
26. PDL Inventory service Run report service Visualisation
27. SUMMARY THE TAKE-HOME Separation of data and logic Consistent code standards Puppet-based ecosystem
28. QUESTIONS ? ! ‽
29. THANK YOU Ben Kero (@bkero) Daniel Maher (@phrawzty) Mozilla IT/Ops (@MozillaIT)