Logstash configuration file that allows you to parse an old file with the correct timestamps via: "nc localhost 3333 < yourlogfile.log "

logstash-haproxy.conf

input {
  tcp { 
    type => "haproxy"
    port => 3333
  } 
}

filter {
  grok {
    type => "haproxy"
    # See the following URL for a complete list of named patterns
    # logstash/grok ships with by default:
    # https://github.com/logstash/logstash/tree/master/patterns
    #
    # The grok filter will use the below pattern and on successful match use
    # any captured values as new fields in the event.
    pattern => "%{HAPROXYHTTP}"
  }

  date {
    type => "haproxy"
    # Try to pull the timestamp from the 'timestamp' field (parsed above with
    # grok). The apache time format looks like: "18/Aug/2011:05:44:34 -0700"
    syslog_timestamp => ["MMM  d HH:mm:ss", "MMM dd HH:mm:ss"]
  }
}

output {
  elasticsearch {
    # Setting 'embedded' will run  a real elasticsearch server inside logstash.
    # This option below saves you from having to run a separate process just
    # for ElasticSearch, so you can get started quicker!
    embedded => true
  }
}