input {
  file {
     path => ["/var/log/syslog"]
     type => "syslog"
     start_position => "beginning"
   }
}
filter {
       if [type] == "syslog" {
    grok {
      match => { "message" => "%{SYSLOGTIMESTAMP:syslog_timestamp} %{SYSLOGHOST:syslog_hostname} %{DATA:syslog_program}(?:\[%{POSINT:syslog_pid}\])?: %{GREEDYDATA:syslog_message}" }
      add_field => [ "received_at", "%{@timestamp}" ]
      add_field => [ "received_from", "%{host}" ]
    }
    date {
      match => [ "syslog_timestamp", "MMM  d HH:mm:ss", "MMM dd HH:mm:ss" ]
      target => "syslog_timestamp"
    }
  }
}
output{
  elasticsearch{
    hosts => ["localhost:9200"] 
    index => "syslog-monitor" 
  }
}