curl -XPOST localhost:9200/test/Materials/Steel/_update?pretty=true -d '
{
    "lang": "groovy",
    "script_file": "updateDocument",
    "scripted_upsert":true,
    "params": {
        "update": {
            "foo": "bar"
        },
        "timestamp": 130
    }
}'

Response:
{
  "error" : "ActionRequestValidationException[Validation Failed: 1: script or doc is missing;]",
  "status" : 400
}