Copy processor

This documentation describes using the copy processor in OpenSearch ingest pipelines. Consider using the Data Prepper copy_values processor, which runs on the OpenSearch cluster, if your use case involves large or complex datasets.

Copy processor

The copy processor copies an entire object in an existing field to another field.

Syntax

The following is the syntax for the copy processor:

{
    "copy": {
      "source_field": "source_field", 
      "target_field": "target_field",
      "ignore_missing": true,
      "override_target": true,
      "remove_source": true
    }
}

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Configuration parameters

The following table lists the required and optional parameters for the copy processor.

Parameter	Required/Optional	Description
`source_field`	Required	The name of the field to be copied. Supports template snippets.
`target_field`	Required	The name of the field to be copied to. Supports template snippets.
`ignore_missing`	Optional	Specifies whether the processor should ignore documents that do not contain the specified `source_field`. If set to `true`, the processor does not modify the document if the `source_field` does not exist or is `null`. Default is `false`.
`override_target`	Optional	Specifies whether the processor should override the `target_field` if it already exists in the document. If set to `true`, the processor overrides the value of `target_field` if it already exists. Default is `false`.
`remove_source`	Optional	Specifies whether the processor should remove the `source_field` after it has been copied. If set to `true`, the processor removes the `source_field` from the document. Default is `false`.
`description`	Optional	A brief description of the processor.
`if`	Optional	A condition for running the processor.
`ignore_failure`	Optional	Specifies whether the processor continues execution even if it encounters an error. If set to `true`, the failure is ignored. Default is `false`.
`on_failure`	Optional	A list of processors to run if the processor fails.
`tag`	Optional	An identifier tag for the processor. Useful for debugging in order to distinguish between processors of the same type.

Using the processor

Follow these steps to use the processor in a pipeline.

Step 1: Create a pipeline

The following query creates a pipeline named copy_object that copies a nested object from one field to the root level:

PUT /_ingest/pipeline/copy_object
{
  "description": "Pipeline that copies object.",
  "processors": [
    {
      "copy": {
        "source_field": "message.content", 
        "target_field":"content",
        "ignore_missing": true,
        "override_target": true,
        "remove_source": true
      }
    }
  ]
}

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Step 2 (Optional): Test the pipeline

It is recommended that you test your pipeline before you ingest documents.

To test the pipeline, run the following query:

POST _ingest/pipeline/copy_object/_simulate
{
  "docs": [
    {
      "_index": "testindex1",
      "_id": "1",
      "_source":{
         "message": {
          "content": {
            "foo": "bar",
            "zoo": [1, 2, 3]
          }
         }
      }
    }
  ]
}

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Response

The following example response confirms that the pipeline is working as expected:

{
  "docs": [
    {
      "doc": {
        "_index": "testindex1",
        "_id": "1",
        "_source": {
          "content": {
            "foo": "bar",
            "zoo": [1, 2, 3]
          }
        },
        "_ingest": {
          "timestamp": "2023-08-24T18:02:13.218986756Z"
        }
      }
    }
  ]
}

Step 3: Ingest a document

The following query ingests a document into an index named testindex1:

PUT testindex1/_doc/1?pipeline=copy_object
{
  "content": {
    "foo": "bar",
    "zoo": [1, 2, 3]
  }
}

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Step 4 (Optional): Retrieve the document

To retrieve the document, run the following query:

GET testindex1/_doc/1

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