gistfile1.txt

class Chef
  class Resource
    class ManagedTemplate < Template
      def initialize(name, collection=nil, node=nil)
        super(name, collection, node)
        not_if { ::File.exists?(name.sub(/(.*)(\/)/, '\1/noclobber.')) }
      end
    end
  end
end

Chef::Platform.platforms[:default].merge! :managed_template => Chef::Provider::Template

# This is just a small wrapper around template that allows us to add a not_if condition as follows: 
# take the full path of the template "/data/someservice.conf" and check for a file on the filesystem
# called "/data/noclobber.someservice.conf"

# so for this managed_template resource
# managed_template "/data/someservice.conf" do
#   owner "ez"
#   mode 0755
#   source 'someservice.conf.erb'
#   action :create
#   variables :applications => ['foo', 'bar', 'baz']
# end
# 
# a not_if condition as follows gets automatically added for you:
# not_if { File.exists?("/data/noclobber.someservice.conf") } 
#
# This allows for a user of a managed system to say "Hey I've made changes to this
# config file, DO NOT CLOBBER IT! KTHXBYE" by just prepending any file they want to manage by hand with 'noclobber.'