Filter and enhance data with processorsedit

Your use case might require only a subset of the data exported by Functionbeat, or you might need to enhance the exported data (for example, by adding metadata). Functionbeat provides a couple of options for filtering and enhancing exported data.

You can specify a filter_pattern to match the data you want to send. This approach may reduce execution costs because the function running Functionbeat only executes if there is data that matches the pattern.

Another approach (the one described here) is to define processors.


You can define processors in your configuration to process events before they are sent to the configured output. The libbeat library provides processors for:

  • reducing the number of exported fields
  • enhancing events with additional metadata
  • performing additional processing and decoding

Each processor receives an event, applies a defined action to the event, and returns the event. If you define a list of processors, they are executed in the order they are defined in the Functionbeat configuration file.

event -> processor 1 -> event1 -> processor 2 -> event2 ...

It’s recommended to do all drop and renaming of existing fields as the last step in a processor configuration. This is because dropping or renaming fields can remove data necessary for the next processor in the chain, for example dropping the source.ip field would remove one of the fields necessary for the community_id processor to function. If it’s necessary to remove, rename or overwrite an existing event field, please make sure it’s done by a corresponding processor (drop_fields, rename or add_fields) placed at the end of the processor list defined in the input configuration.