Puppet 4 :: Hiera

• Hiera helps to lookup data from data-source
  • Separation of data and logic
  • yaml :: YAML Ain't Markup Language

class motd ( $message = "Welcome to Git Wiki" ) 
{
  file { '/etc/motd':
    ensure => 'file',
    content => $message,
  }
}

• In Puppet 4 the configuration directory stores the hiera.yaml file and we can make use of the defaults found in the file.
• common.yaml

motd::message: "This is a dev system for developers only!"     ## this will ensure that $message param of class motd uses this value

Hiera Configuration

• The Hiera configuration file location puppet config get hiera_config
• Sample hira.yaml

---                        ## start of doc
:backends: yaml            ## scalar mapping
:hierarchy:                ## sequence to find variable value
  - param%{environment}    ## sequence mapping. {environment} => top level variable. {facts.os.hostname} can be used
  - common
:logger: console
:yaml:
  :datadir: "%{settings::confdir}/configuration"

YAML

## Strings (can be unquoted - but quotes are recommended)  
ntp::ntp_local_server: 192.168.0.3
ntp::ntp_local_server: '192.168.0.3'

## Boolean (yes, no, true, false, on, off)
ntp::monitor: false 

## Arrays (Indents are important)
ntp::ntp_regional_server:
  - 'server1'
  - 'server2'
  - true