gistfile1.txt

file {
  'initial-config':
    path    => "${config_file}.bak",
    source  => "${config_file}",
    replace => no,
}
exec {
  'rm config':
    command     => "rm ${initial-config}",
    subscribe   => File['initial-config'],
    refreshonly => true,
}
file {
  "init_config":
    path => "${config_file}",
    require => Exec['rm config'],
    replace => no,
    content => template("${module_name}/foobar.erb")
}

define stupidfile(
  $name,
  $path = $name,
  $content = undef
) {
  file {$name:
    ensure  => 'present',
    path    => $path,
    replace => false,
    content => $content,
    require => Exec['rm initial file'],
  }
  exec {"rm_initial_${name}":
    creates => "${path}.lck",
    command => "rm ${path}; echo 'THIS FILE PREVENTS PUPPET FROM OVERWRITING ${path}' >  ${path}.lck",
    path    => ['/bin','/usr/bin'],
  }
}

There obviously is an error in what I wrote :) the require => Exec['THIS IS WRONG'] ;)