/modules/filebeat/manifests/configfile.pp
$input_type    = "log",

/modules/filebeat/templates/filebeat.yml.erb
input_type: <%= @input_type %>

/manifests/nodes/mynode.pp
filebeat::configfile { "filebeat-test":
    input_type => "foo",                                                                                                             
  }


##### 
Error: Could not retrieve catalog from remote server: Could not intern from text/pson: wrong constant name foo
Warning: Not using cache on failed catalog
Error: Could not retrieve catalog; skipping run