Add copy ingest processor

_ingest-pipelines/processors/copy.md

@@ -0,0 +1,151 @@
+---
+layout: default
+title: Copy
+parent: Ingest processors
+nav_order: 35
+redirect_from:
+   - /api-reference/ingest-apis/processors/copy/
+---
+
+# 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: 
+
+```json
+{
+    "copy": {
+      "source_field": "source_field", 
+      "target_field": "target_field",
+      "ignore_missing": true,
+      "override_target": true,
+      "remove_source": true
+    }
+}
+```
+{% include copy-curl.html %}
+
+## 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]({{site.url}}{{site.baseurl}}/ingest-pipelines/create-ingest/#template-snippets). |
+`target_field`  | Required  | The name of the field to be copied to. Supports [template snippets]({{site.url}}{{site.baseurl}}/ingest-pipelines/create-ingest/#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: 
+
+```json
+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
+      }
+    }
+  ]
+}
+```
+{% include copy-curl.html %}
+
+**Step 2 (Optional): Test the pipeline**
+
+It is recommended that you test your pipeline before you ingest documents.
+{: .tip}
+
+To test the pipeline, run the following query:
+
+```json
+POST _ingest/pipeline/copy_object/_simulate
+{
+  "docs": [
+    {
+      "_index": "testindex1",
+      "_id": "1",
+      "_source":{
+         "message": {
+          "content": {
+            "foo": "bar",
+            "zoo": [1, 2, 3]
+          }
+         }
+      }
+    }
+  ]
+}
+```
+{% include copy-curl.html %}
+
+**Response**
+
+The following example response confirms that the pipeline is working as expected:
+
+```json
+{
+  "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`:
+
+```json
+PUT testindex1/_doc/1?pipeline=copy_object
+{
+  "content": {
+    "foo": "bar",
+    "zoo": [1, 2, 3]
+  }
+}
+```
+{% include copy-curl.html %}
+
+**Step 4 (Optional): Retrieve the document**
+
+To retrieve the document, run the following query:
+
+```json
+GET testindex1/_doc/1
+```
+{% include copy-curl.html %}