file_content.rb

#
# file_content.rb
#
# Amos Shapira: cloned from exists.rb at https://gist.github.com/chrisleavoy/5312010,
# returns the content of the file found
#
# James Fellows 8/8/12: cloned from git://gist.github.com/1160472.git then 
# modified to resolve puppet:/// paths
#
# Copyright 2011 Puppet Labs Inc.
# Copyright 2011 Krzysztof Wilczynski
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#

module Puppet::Parser::Functions
  newfunction(:file_content, :type => :rvalue, :doc => <<-EOS
Returns the content of the file if it is found on Puppet Master.

Prototype:

    file_content(x)

Where x is a file name.

  The function will also look in the puppetmaster modules directory if the 
  file path is relative rather than absolute, e.g. 'puppet:///modules/my_module/file'

  An error will be thrown if the a module by that name doesn't exist.
    EOS
  ) do |arguments|

    #
    # This is to ensure that whenever we call this function from within
    # the Puppet manifest or alternatively from a template it will always
    # do the right thing ...
    #
    arguments = arguments.shift if arguments.first.is_a?(Array)

    raise Puppet::ParseError, "file_conent(): Wrong number of arguments " +
      "given (#{arguments.size} for 1)" if arguments.size < 1

    file = arguments.shift
    raise Puppet::ParseError, 'file_content(): Requires a string type ' +
      'to work with' unless file.is_a?(String)

    if file.slice!('puppet:///')
    # Perform relative lookup in modules/files dir.
        # strip off the modules prefix too if it's there
        file.slice!('modules/')
        env = compiler.environment.to_s
        mod_name, file = file.split(File::SEPARATOR, 2)
        mod = Puppet::Module.find(mod_name, env)
        raise Puppet::Error, "file_content(): invalid module name #{mod_name}" unless mod
        path = mod.path
        file = File.join(path, "files", file)
    else
        file = File.expand_path(file)
    end

    result = File.read(file)

  end

end

# vim: set ts=2 sw=2 et :

I've created a clone of this called "file_content" which returns the content of the file. This is useful because file() doesn't seem to work with relative paths, and I need them in order to work with fileserver mount points.