logstash/logstash — pull request #302 by paulczar (2013-01-04 05:26:30+00:00)
Title: outputs / elasticsearch_river

fixed line 209

from: header = { "index" => { "_index" => index, "_type" => type } }
to : header = { "index" => { "_index" => event.sprintf(@index), "_type" => event.sprintf(@type) } }

the allows index to properly parse out variables such as the date {+YYY-mm-dd}