Copy fieldsedit

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.

Exampleedit

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"
  }
}

Configuration settingsedit

Elastic Agent processors execute before ingest pipelines, which means that your processor configurations cannot refer to fields that are created by ingest pipelines or Logstash. For more limitations, refer to What are some limitations of using processors?

Name Required Default Description

fields

Yes

List of from and to pairs to copy from and to. You can use the @metadata. prefix to copy values from or to event metadata.

fail_on_error

No

true

Whether to fail if an error occurs. If true and an error occurs, any changes are reverted, and the original is returned. If false, processing continues even if an error occurs.

ignore_missing

No

false

Whether to ignore events that lack the source field. If false, the processing of an event will fail if a field is missing.