Logstash: Unable to create index in elasticsearch protected by Shield

 I've protected elasticsearch using SHIELD  and elasticsearch is prompting me
 for credentials when trying to access using SENSE, or KIBANA as expected.
       But It is not allowing me to create index using logstash. It show security
  exception message,

Settings: Default filter workers: 2
←[31m[401] {"error":{"root_cause":[{"type":"security_exception","reason":"missin
g authentication token for REST request [/_template/logstash]","header":{"WWW-Au
thenticate":"Basic realm="shield""}}],"type":"security_exception","reason":"mi
ssing authentication token for REST request [/_template/logstash]","header":{"WW
W-Authenticate":"Basic realm="shield""}},"status":401} {:class=>"Elasticsearch
::Transport::Transport::Errors::Unauthorized", :level=>:error}←[0m

  My question is how do I send credentials so as to authenticate logstash?

Have you been through https://www.elastic.co/guide/en/shield/current/logstash.html