[Backport 2.9] [DOC] Add ingest processors documentation

_api-reference/ingest-apis/create-ingest.md

@@ -0,0 +1,100 @@
+---
+layout: default
+title: Create pipeline
+parent: Ingest pipelines
+grand_parent: Ingest APIs
+nav_order: 10
+redirect_from:
+  - /opensearch/rest-api/ingest-apis/create-update-ingest/
+---
+
+# Create pipeline
+
+Use the create pipeline API operation to create or update pipelines in OpenSearch. Note that the pipeline requires you to define at least one processor that specifies how to change the documents. 
+
+## Path and HTTP method
+
+Replace `<pipeline-id>` with your pipeline ID:
+
+```json
+PUT _ingest/pipeline/<pipeline-id>
+```
+#### Example request
+
+Here is an example in JSON format that creates an ingest pipeline with two `set` processors and an `uppercase` processor. The first `set` processor sets the `grad_year` to `2023`, and the second `set` processor sets `graduated` to `true`. The `uppercase` processor converts the `name` field to uppercase.
+
+```json
+PUT _ingest/pipeline/my-pipeline
+{
+  "description": "This pipeline processes student data",
+  "processors": [
+    {
+      "set": {
+        "description": "Sets the graduation year to 2023",
+        "field": "grad_year",
+        "value": 2023
+      }
+    },
+    {
+      "set": {
+        "description": "Sets graduated to true",
+        "field": "graduated",
+        "value": true
+      }
+    },
+    {
+      "uppercase": {
+        "field": "name"
+      }
+    }
+  ]
+}
+```
+{% include copy-curl.html %}
+
+To learn more about error handling, see [Handling pipeline failures]({{site.url}}{{site.baseurl}}/api-reference/ingest-apis/pipeline-failures/).
+
+## Request body fields
+
+The following table lists the request body fields used to create or update a pipeline. 
+
+Parameter | Required | Type | Description
+:--- | :--- | :--- | :---
+`processors` | Required | Array of processor objects | An array of processors, each of which transforms documents. Processors are run sequentially in the order specified.
+`description` | Optional | String | A description of your ingest pipeline. 
+
+## Path parameters
+
+Parameter | Required | Type | Description
+:--- | :--- | :--- | :---
+`pipeline-id` | Required | String | The unique identifier, or pipeline ID, assigned to the ingest pipeline. 
+
+## Query parameters
+
+Parameter | Required | Type | Description
+:--- | :--- | :--- | :---
+`cluster_manager_timeout` | Optional | Time | Period to wait for a connection to the cluster manager node. Defaults to 30 seconds.
+`timeout` | Optional | Time | Period to wait for a response. Defaults to 30 seconds. 
+
+## Template snippets
+
+Some processor parameters support [Mustache](https://mustache.github.io/) template snippets. To get the value of a field, surround the field name in three curly braces, for example, `{% raw %}{{{field-name}}}{% endraw %}`.
+
+#### Example: `set` ingest processor using Mustache template snippet
+
+The following example sets the field `{% raw %}{{{role}}}{% endraw %}` with a value `{% raw %}{{{tenure}}}{% endraw %}`:
+
+```json
+PUT _ingest/pipeline/my-pipeline
+{
+ "processors": [
+    {
+      "set": {
+        "field": "{% raw %}{{{role}}}{% endraw %}",
+        "value": "{% raw %}{{{tenure}}}{% endraw %}"
+         }
+    }
+  ]
+}
+```
+{% include copy-curl.html %}

_api-reference/ingest-apis/delete-ingest.md

@@ -1,44 +1,27 @@
 ---
 layout: default
-title: Delete a pipeline
-parent: Ingest APIs
-nav_order: 14
+title: Delete pipeline
+parent: Ingest pipelines
+grand_parent: Ingest APIs
+nav_order: 13
 redirect_from:
   - /opensearch/rest-api/ingest-apis/delete-ingest/
 ---
 
-# Delete a pipeline
+# Delete pipeline
 
-If you no longer want to use an ingest pipeline, use the delete ingest pipeline API operation.
+Use the following request to delete a pipeline. 
 
-## Example
+To delete a specific pipeline, pass the pipeline ID as a parameter:
 
-```
-DELETE _ingest/pipeline/12345
+```json
+DELETE /_ingest/pipeline/<pipeline-id>
 ```
 {% include copy-curl.html %}
 
-## Path and HTTP methods
-
-Delete an ingest pipeline based on that pipeline's ID.
-
-```
-DELETE _ingest/pipeline/
-```
-
-## URL parameters
-
-All URL parameters are optional.
-
-Parameter | Type | Description
-:--- | :--- | :---
-master_timeout | time | How long to wait for a connection to the master node.
-timeout | time | How long to wait for the request to return.
-
-## Response
+To delete all pipelines in a cluster, use the wildcard character (`*`):
 
 ```json
-{
-  "acknowledged" : true
-}
-```
+DELETE /_ingest/pipeline/*
+```
+{% include copy-curl.html %}

_api-reference/ingest-apis/get-ingest.md

@@ -1,59 +1,62 @@
 ---
 layout: default
-title: Get ingest pipeline
-parent: Ingest APIs
-nav_order: 10
+title: Get pipeline
+parent: Ingest pipelines
+grand_parent: Ingest APIs
+nav_order: 12
 redirect_from:
   - /opensearch/rest-api/ingest-apis/get-ingest/
 ---
 
-## Get ingest pipeline
+# Get pipeline
 
-After you create a pipeline, use the get ingest pipeline API operation to return all the information about a specific ingest pipeline.
+Use the get ingest pipeline API operation to retrieve all the information about the pipeline.
 
-## Example
+## Retrieving information about all pipelines
 
-```
-GET _ingest/pipeline/12345
+The following example request returns information about all ingest pipelines:
+
+```json
+GET _ingest/pipeline/
 ```
 {% include copy-curl.html %}
 
-## Path and HTTP methods
+## Retrieving information about a specific pipeline
 
-Return all ingest pipelines.
+The following example request returns information about a specific pipeline, which for this example is `my-pipeline`: 
 
+```json
+GET _ingest/pipeline/my-pipeline
 ```
-GET _ingest/pipeline
-```
-
-Returns a single ingest pipeline based on the pipeline's ID.
-
-```
-GET _ingest/pipeline/{id}
-```
-
-## URL parameters
-
-All parameters are optional.
-
-Parameter | Type | Description
-:--- | :--- | :---
-master_timeout | time | How long to wait for a connection to the master node.
+{% include copy-curl.html %}
 
-## Response
+The response contains the pipeline information:
 
 ```json
 {
-  "pipeline-id" : {
-    "description" : "A description for your pipeline",
-    "processors" : [
+  "my-pipeline": {
+    "description": "This pipeline processes student data",
+    "processors": [
       {
-        "set" : {
-          "field" : "field-name",
-          "value" : "value"
+        "set": {
+          "description": "Sets the graduation year to 2023",
+          "field": "grad_year",
+          "value": 2023
+        }
+      },
+      {
+        "set": {
+          "description": "Sets graduated to true",
+          "field": "graduated",
+          "value": true
+        }
+      },
+      {
+        "uppercase": {
+          "field": "name"
         }
       }
     ]
   }
 }
-```
+```

_api-reference/ingest-apis/index.md

@@ -9,6 +9,13 @@ redirect_from:
 
 # Ingest APIs
 
-Before you index your data, OpenSearch's ingest APIs help transform your data by creating and managing ingest pipelines. Pipelines consist of **processors**, customizable tasks that run in the order they appear in the request body. The transformed data appears in your index after each of the processor completes.
+Ingest APIs are a valuable tool for loading data into a system. Ingest APIs work together with [ingest pipelines]({{site.url}}{{site.baseurl}}/api-reference/ingest-apis/ingest-pipelines/) and [ingest processors]({{site.url}}{{site.baseurl}}/api-reference/ingest-apis/ingest-processors/) to process or transform data from a variety of sources and in a variety of formats. 
 
-Ingest pipelines in OpenSearch can only be managed using ingest API operations. When using ingest in production environments, your cluster should contain at least one node with the node roles permission set to `ingest`. For more information on setting up node roles within a cluster, see [Cluster Formation]({{site.url}}{{site.baseurl}}/opensearch/cluster/).
+## Ingest pipeline APIs
+
+Simplify, secure, and scale your OpenSearch data ingestion with the following APIs:
+
+- [Create pipeline]({{site.url}}{{site.baseurl}}/api-reference/ingest-apis/create-ingest/): Use this API to create or update a pipeline configuration.
+- [Get pipeline]({{site.url}}{{site.baseurl}}/api-reference/ingest-apis/get-ingest/): Use this API to retrieve a pipeline configuration.
+- [Simulate pipeline]({{site.url}}{{site.baseurl}}/api-reference/ingest-apis/simulate-ingest/): Use this pipeline to test a pipeline configuration.
+- [Delete pipeline]({{site.url}}{{site.baseurl}}/api-reference/ingest-apis/delete-ingest/): Use this API to delete a pipeline configuration.