title: How to have Logstash shipper to grab a value from a local file and passed to indexer ?
body: <p>I have a logstash project that in general is of this architecture: </p>
  
  <p>" 
  Several logstash Shippers ==> Redis ==> Logstash Indexer ==> ES
  ".  </p>
  
  <p>For each individual Shipper, it needs to grab an ID VALUE from a local file, and have it passed to the Logstash Indexer, that will be used as its unique "INDEX" String. But I don't know how this can be done. Two Quesions here: </p>
  
  <p>a) how this value may be grabbed from a file ? </p>
  
  <p>b) how this value may be passed from shipper to the indexer ? </p>
  
  <p>I know how it works if this string is part of the "path" value, but if it was from a file, I am still clueless.  Anyone has any clue for that ? </p>
  
  <p>John. </p>