Logstash get only message content

I would like to read a file line-by-line and put only the rows into a queue. The process works but in the queue there are a lot of other information such as version and so one.

Do you have any idea?

Here is my config file:

input {
   file {
     codec => plain
     path => "/apps/*.txt"
  }
}
filter{

}
output {
    stomp {
        host => "localhost"
        port => "61613"
        destination => "stomp-test"
        debug => "true"
        headers => {
                "amq-msg-type" => "text"
                "my_custom_header" => "kutya"
        }
    }
}

The example.txt contains: This is my test row!

The MQ body contains: {"message":"This is my test row!","@version":"1","@timestamp":"2017-01-21T13:42:21.084Z","path":"/apps/1.txt","host":"ol7"}

My expected result should be: This is my test row!

Thanks in advance.

Solution

The stomp output, as it currently stands, will only write JSON to the destination queue as can be seen in the source code of that plugin:

t.send(event.sprintf(@destination), event.to_json, headers)
                                          ^
                                          |
                                     writes JSON

The best you can do is to remove all other fields using a mutate/remove_field filter, like this:

filter {
  mutate {
    remove_field => ["@timestamp", "@version", "path", "host"]
  }
}

Then you'll get only this in your destination queue:

{"message":"This is my test row!"}