I have a Logstash configuration that originally has a udp input processing JSON on a port. Recently, and beyond my control, another team started sending a specific string (for example ‘some string here’) of text once every second on the same port.

I cannot figure out how to register as input both the JSON text we are expecting AND the extra string. I would like to drop that extra string. Is this possible in logstash?

input {
  udp {                                           
    codec => 'json'                               
    port => 22222                                 
    add_field => { 'data_source' => 'input_a' }
  }                                               
}