Add current timestamp to a logstash_processed_at field

Elastic Stack Logstash
3

I thought that logs like

Nov  1 04:09:02 my-hostname postfix/cleanup[13509]: 3yRj7y3g8wz36b0: info: header X-MyHeader: 1585

are processed by Logstash automatically without extra configuration.

I think that Logstash uses some default grok patterns like SYSLOGBASE2 to extract timestamp and replace @timestamp with extracted value. So, I don't have any custom date filters.

Idea number 3:

ruby { 
    code => "event.set('logstash_processed_at', Time.now());"
}