Elasticsearch > Logstash > _ID を任意な値に設定

output {
    elasticsearch { 
        document_id => "%{some_id_field}"
    }
}

output {
  elasticsearch {
    document_id => "%{some_id_field}" # _IDをsome_id_fieldとする
    hosts => ["http://elasticsearch:9200/"]
    user => "elastic"
    password => "xxxxx"
    index => "some_index"
    ...
  }
}