title: Problem in ILM rollover alias in elastic stack
body: <p>I am using logstash to ingest flat files into an elastic cluster and I want to make use of ILM.
  I have configured the lifecycle policy and created an index template in kibana. In my logstash file, I am using the policy name and the rollover alias.
  Here is my problem:</p>
  <ul>
  <li>If I don't give the rollover alias in the index template, it throws error <code>setting [index.lifecycle.rollover_alias] for index is empty or not defined</code> when it tries to rollover according to the rollover conditions.</li>
  <li>But if I do give it, then it complains that there is duplicate alias.</li>
  <li>If I keep it in the index template and remove the alias from the logstash conf file, then logstash doesn't send the data to the correct index. It tries sending to some default index name.</li>
  </ul>
  <p>Here is my output plugin from logstash conf file:</p>
  <pre><code>output {
      elasticsearch {
          hosts =&gt;  XXXX
          ilm_enabled =&gt; true
          ilm_rollover_alias =&gt; &quot;myaliasname&quot;
          ilm_pattern =&gt; &quot;000001&quot;
          ilm_policy =&gt; &quot;my_policy&quot;
          user =&gt; XXXX
          password =&gt; XXXX
          manage_template =&gt; false    
      }
  }
  </code></pre>
  <p>I have searched the elastic forums as well as on SO, but can't seem to narrow down the issue.
  Any help is greatly appreciated.</p>
  <p>P.S. I am not using data streams currently.</p>