fluentd/label/default_output/drop_event.yml

agent:
  config:
    label:
      default_output:
        filter:
          drop_event:
            tag: '**'
            type: grep
            exclude:
              - name: drop_event
                regexp: ^.+?$
          remove_drop_event_key:
            require:
              - drop_event
            tag: '**'
            type: record_transformer
            remove_keys: drop_event