deferred issue

foo.pp

notify { "hello ${Deferred('pid', [])}": }
notify { "hello ${pid()}": }
file { '/tmp/foo':
  ensure  => file,
  content => Deferred('pid', []),
}

pid.rb

Puppet::Functions.create_function(:pid) do
  def pid
    Process.pid.to_s
  end
end

Put pid.rb at foo/lib/puppet/functions/pid.rb. Then run

$ puppet apply foo.pp --modulepath foo
Notice: Compiled catalog for localhost in environment production in 0.04 seconds
Notice: hello Deferred({'name' => 'pid', 'arguments' => []})
Notice: /Stage[main]/Main/Notify[hello Deferred({'name' => 'pid', 'arguments' => []})]/message: defined 'message' as 'hello Deferred({\'name\' => \'pid\', \'arguments\' => []})'
Notice: hello 68774
Notice: /Stage[main]/Main/Notify[hello 68774]/message: defined 'message' as 'hello 68774'
Notice: /Stage[main]/Main/File[/tmp/foo]/ensure: defined content as '{md5}9319e8ccd187e2773282ec8d5a6edc8b'
Notice: Applied catalog in 0.02 seconds
$ cat /tmp/foo
68774

If you do it like this, it should work

notify { 'hello notify':
    message => "hello ${Deferred('pid', [])}",
}

Still an issue even with that change.

You cannot have Deferred inside of an interpolation and expect that to be resolved on the agent. You need to send the string and the arguments and do a Deferred sprintf or similar.