Add ingest field access pattern to specification (#5309)

* Add spec for ingest pipeline field access pattern.

* contrib

Author: jbaiera

output/openapi/elasticsearch-openapi.json

@@ -73,6 +73,13 @@ export class Pipeline {
    * @availability serverless
    */
   modified_date_millis?: EpochTime<UnitMillis>
+  /**
+   * Controls how processors in this pipeline should read and write data on a document's source.
+   * @server_default classic
+   * @availability stack since=9.2.0
+   * @availability serverless
+   */
+  field_access_pattern?: FieldAccessPattern
 }
 
 // Unused .. but let's keep it for now
@@ -104,3 +111,8 @@ export class PipelineConfig {
    */
   processors: ProcessorContainer[]
 }
+
+export enum FieldAccessPattern {
+  classic,
+  flexible
+}

output/openapi/elasticsearch-serverless-openapi.json

@@ -20,6 +20,7 @@
 import { RequestBase } from '@_types/Base'
 import { Id, Metadata, VersionNumber } from '@_types/common'
 import { Duration } from '@_types/Time'
+import { FieldAccessPattern } from '@ingest/_types/Pipeline'
 import { ProcessorContainer } from '@ingest/_types/Processors'
 
 /**
@@ -86,5 +87,12 @@ export interface Request extends RequestBase {
      * @server_default false
      */
     deprecated?: boolean
+    /**
+     * Controls how processors in this pipeline should read and write data on a document's source.
+     * @server_default classic
+     * @availability stack since=9.2.0
+     * @availability serverless
+     */
+    field_access_pattern?: FieldAccessPattern
   }
 }