Generic Augeas based facter plugin

aug_facts.ini

# This is the configuration file
# for the augeas_generic.rb facter plugin
#
# Each section defines a new fact
# and has the following attributes:
#  - type:   Optional, the type of value to retrieve.
#            Possible values: "single" and "multiple".
#            Defaults to "single".
#  - path:   Mandatory, the path to the value.
#  - method: Optional, how to retrieve the value.
#            Possible values: "value", "label".
#            Defaults to "value".
#            When "value" is used, the node value is returned.
#            When "label" is used, the node label is returned.
#  - sep:    Optional, the separator for multiple values.
#            Defaults to ",".

[augeasversion]
type   = single
path   = /augeas/version
method = value

[root_shell]
type = single
path = /files/etc/passwd/root/shell

[root_device]
type = single
path = /files/etc/mtab/*[file="/"]/spec

[home_device]
# a home device
# type=single is default
path = /files/etc/mtab/*[file="/home"]/spec

[users]
type = multiple
sep  = :
path = /files/etc/passwd/*
method = label

augeas_generic.rb

require 'augeas'
aug = Augeas::open(nil, nil, Augeas::NO_LOAD)

DEFAULT_SEP = ','

def path_label(path)
  path.split("/")[-1].split("[")[0]
end

def get_value(aug, path, method)
  if method == 'label'
    path_label(path)
  elsif method == 'value'
    aug.get(path)
  else
    Facter.debug("Unknown method #{method} to retrieve path #{path}")
    return nil
  end
end

facts_file = '/home/rpinson/bas/facter/aug_facts.ini'

aug.transform(
  :lens => 'Puppet.lns',
  :name => 'Aug_Facts',
  :incl => facts_file
)
aug.load!

aug.match("/files#{facts_file}/*[label()!='#comment']").each do |fact|
  fact_name = path_label(fact)
  Facter.debug("Adding fact #{fact_name}")
  path  = aug.get("#{fact}/path")
  unless path
    Facter.debug("No path specified for fact #{fact_name}. Ignoring.")
    next
  end
  type  = aug.get("#{fact}/type") || 'single'
  method = aug.get("#{fact}/method") || 'value'
  Facter.add(fact_name) do 
    setcode do
      if type == 'single'
        get_value(aug, path, method) || nil
      elsif type == 'multiple'
        sep = aug.get("#{fact}/sep") || DEFAULT_SEP
        vals = Array.new()
        aug.match(path).each do |p|
          Facter.debug("Adding value from path #{p}")
          vals.push(get_value(aug, p, method))
        end
        vals.join(sep)
      else
        Facter.debug("Unknown type #{type} for fact #{fact_name}. Ignoring")
      end
    end
  end
end