Guided exercise tutorial introduction for 1st Puppet BarCamp/HackDay in New Delhi, March 13, 2010

1. First Moves
with Puppet
New Delhi Puppet HackDay/
BarCamp March 13, 2010
Presented by
Slideshare Operations Engineering/Julie Tsai

2. Today
 Quick Primer
 Useful Commands
 Puppeting Sudoers I — Permissions
 Puppeting Sudoers II — OS Conditions
 Puppeting Sudoers III — Inheriting Class
 Facter
 References
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3. Quick Primer: How It Flows
Ref. http://www.linuxforu.com/wp-content/uploads/2009/06/puppet_diagram.png 3

4. Quick Primer: Learning the Lingo
Resource – instance of native type, plugin, or
definition, i.e. user, exec, file
Capitalized resource: invoked by other resources of previously
defined resource, i.e. file foo.txt laver invoked as File[“foo.txt”]
Class - resource(s) description with title, file, attributes
Definition – abstract description of class, can be
invoked multiple times
Node – host instance (physical or virtual)
Collection – groups of resources
Recipe – sample puppet code (manifests/*.pp)
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5. Quick Primer: Data Parameters
Variables – substitution values
Arrays – grouped list of values
Attributes – statement(s) describing
resources
Literals – string values that needn’t be
interpolated
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6. Quick Primer: Variable Scoping
 Overridable variable defaults defined only in
outer scope of resource instances
 Declarative language: Within the same-level
scope, variables can only be defined once
 Qualified variables are a method of passing
parameters from a class
class mothership {
$server = “juno”
}
class satellite {
$ms = $mothership::server
}
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7. Quick Primer: Where Things Are
Note: below assumes default install in /etc
 /etc/puppet/fileserver.conf (used by puppermasterd)
path /var/lib/puppet/files
allow 10.100.0.0/24
 /etc/puppet/puppet.conf (used by clients’ puppetd)
vardir = /var/lib/puppet
logdir = /var/log/puppet
classfile = $vardir/classes.txt
 /etc/puppet/manifests/[../..]/*.pp (architecture varies)
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8. Quick Primer: A Client Directory Tree
puppetclient01:/var/lib/puppet
|-> classes.txt – node’s class membership
|-> cientbucket – hashed config artifacts
|-> lib
|-> localconfig.yaml
|-> ssl – authentication certs
|-> state – checksums, entropy-tracking
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9. Quick Primer: Master Directory Tree
puppetmasterd:/var/lib/puppet
|-> bucket
|-> classes.txt
|-> clientbucket
|-> client_yaml
|-> lib
|-> localconfig.yaml
|-> reports
|-> rrd
|-> ssl
|-> state
|-> yaml
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10. Useful Commands to Get Started
puppet <puppetscript.pp> - run standalone script
-l /path/to/file.log – logpath
-d – debug
--noop – dry-run
puppetd – daemon on client that schedules retrieval of
configs from puppetmaster and applies locally
-d – debug
--test – verbose logging
--noop – dry-run
-l /path/to/log – log path
facter – find out local node’s values for reserved classes
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11. Puppeting Sudoers I — Permissions
Configure /etc/puppet/manifests/sudoers.pp :
file { "/etc/sudoers":
owner => root,
group => wheel,
mode => 400,
}
And run:
[puppet@puppet manifests]# puppet –noop –d /etc/puppet/
manifests/sudoers.pp
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12. Puppeting Sudoers II — Operating Conditions
Now, correct with /etc/puppet/manifests/sudoers2.pp
file { "/etc/sudoers”:
mode => $operatingsystem ? {
centos => "440",
gentoo => "440",
suse => "640",
default => ”400",
},
owner => root,
group => root,
} 12

13. Puppeting Sudoers III — Inheriting Class
/etc/puppet/manifests/sudoers3.pp
class unix {
file { "/etc/sudoers":
owner => root,
group => root,
}
service {
"sshd":
ensure => running,
}
}
class centos_mycompany inherits unix {
File["/etc/sudoers"] { mode => 440 }
}
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14. Puppeting Sudoers III — Inheriting Class (cont.)
/etc/puppet/manifests/sudoers3.pp
node default {
include unix
}
node bastionhost {
include centos_mycompany
}
And run:
[puppet@puppet manifests]# puppet –d –noop sudoers3.pp
[puppet@puppet manifests]# cat /var/lib/puppet/classes.txt
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15. Puppeting Sudoers III — Inheriting Class (cont. 2)
Use Facter to defind nodename:
[puppet@puppet manifests]# facter | egrep -i 'fqdn|hostname’
/etc/puppet/manifests/sudoers3.pp
node'puppet.us-west-1.compute.internal' {
include centos_mycompany
}
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16. Facts about Facter
 Facter is a Puppet utility that
discovers relevant “facts” that
puppet can use to dynamically
populate puppet manifest variables
 Executing command-line Facter
can show you the reserved
variables like FQDN, hostname,
kernel, architecture, sshdsakey, etc.
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17. References
 Reductive Labs Puppet Guides
http://docs.reductivelabs.com/guides/
 Glossary of Terms
http://reductivelabs.com/trac/puppet/wiki/
GlossaryOfTerms
 Resource Attributes
http://reductivelabs.com/trac/puppet/wiki/
TypeReference#metaparameters
 Nice vimrc for Puppet
http://www.davidpashley.com/blog/systems-
administration/puppet/vim-highlighting.html
 Classic LISA ‘98 paper on best-practice infrastructures
http://www.infrastructures.org/papers/bootstrap/
bootstrap.html 17