Copy fields

The copy_fields processor takes the value of a field and copies it to a new field.

You cannot use this processor to replace an existing field. If the target field already exists, you must drop or rename the field before using copy_fields.

This configuration:

- copy_fields:
    fields:
      - from: message
        to: event.original
    fail_on_error: false
    ignore_missing: true

Copies the original message field to event.original:

{
  "message": "my-interesting-message",
  "event": {
      "original": "my-interesting-message"
  }
}