Index lost the alias rollover

Elastic Stack Elasticsearch
5

thank you!

but i dont understand it very well, then the fluentd.conf the index name should be
the alias which use in the template?

for example, i make the lifepolicy, then the template,

PUT _index_template/indextemplate
{
  "index_patterns": ["index-*"], 
  "template": {
    "settings": {
      "number_of_shards": 1,
      "number_of_replicas": 1,
      "index.lifecycle.name": "index-policy"
      "index.lifecycle.rollover_alias": "indexalias"  
    }
  }

and then create the alias and make it writeable

POST /_aliases
{
  "actions": [
    {
      "add": {
        "index": "index-*",
        "alias": "indexalias",
        "is_write_index": true
      }
    }
  ]

so if understand well the congif should be

<match **>
 @type elasticsearch
 index_name indexalias
 host 
 port 
 user 
 password 
 logstash_format 
</match>