Overwrite @timestamp field

[2knarf (Frank Solli)]

Hello, I'm trying to overwrite the timestamp field with incoming log messages' timestamp, However I am unable to get it working, I have tried searching the forums but I do not find anything that solves my case, attaching configuration:

filter {
  
if [type] == "exim-log" {
    


  
  grok {
    overwrite => [ "message" ]
    match => { "message" => "%{DATESTAMP:timestamp} %{GREEDYDATA:message}" }
    add_tag => [ "_got_syslog_exim_timestamp" ]
  } 

  date {
    match => [ "timestamp" , "yy-MM-dd HH:mm:ss" ]
    timezone => "UTC"
  }


# Not everything has a MessageID but    if it has lets grab it here
  grok {
    overwrite => [ "message" ]
    patterns_dir => "/etc/logstash/patterns"
    match => { "message" => "%{EXIM_MESSAGE_ID:message_id} %{GREEDYDATA:message}" }
    add_tag => [ "_got_syslog_exim_msg_id" ]
    remove_tag => "_grokparsefailure"
  }
 }
}

Example event

{
  "_index": "filebeat-2017.06.29",
  "_type": "exim-log",
  "_id": "AVzzqtOOyDLns164PTmP",
  "_score": 1,
  "_source": {
    "@timestamp": "2017-06-29T11:44:35.220Z",
    "offset": 72175145,
    "@version": "1",
    "input_type": "log",
    "beat": {
      "hostname": "frank-MacBookPro",
      "name": "frank-MacBookPro",
      "version": "5.1.2"
    },
    "host": "frank-MacBookPro",
    "message_id": "1WXXDi-XX60L-Ph",
    "source": "/home/frank/logstash/mainlog.upto-20140214",
    "message": "<= x@x.com H=xt.com x.v) [x] P=esmtp S=22XX id=XXXX@x.v",
    "type": "exim-log",
    "tags": [
      "beats_input_codec_plain_applied",
      "_got_syslog_exim_timestamp",
      "_dateparsefailure",
      "_got_syslog_exim_msg_id"
    ],
    "timestamp": "14-02-11 10:01:34"
  },
  "fields": {
    "@timestamp": [
      1498736675220
    ]
  }
}

Patterns file:

EXIM_MESSAGE_ID [\d\w]{6}-[\d\w]{6}-[\d\w]{2}

[marjan4jc (Marjan)]

maybe you should try like this:

date {
match => [ "timestamp", "YY-MM-dd HH:mm:ss" ]
locale => en
remove_field => timestamp
}