Logstash not streaming to kafka

i've kept a very basic conf file that reads logs from a folder and pushing it to kafka like so:

input {
file
 {
        add_field => { "app_id" => "12345"}
        path => "/tmp/logs/*.log"
        start_position => "beginning"
 }
}
output {
 if [app_id] == "12345" {
        kafka {
                topic_id => "mytopic"
                bootstrap_servers => "kafka_topic_id:9043"
                ssl => false
                }
        }
}

My logstash logs show "pipeline main started". However I do not see anything on kibana. This means either stream is not being pushed to kafka or else from kafka to elastic search data is not being pushed. Have I missed something in the conf?