field alias testing

x-pack/plugins/streams/common/types.ts

@@ -72,7 +72,8 @@ export type ProcessingDefinition = z.infer<typeof processingDefinitionSchema>;
 
 export const fieldDefinitionSchema = z.object({
   name: z.string(),
-  type: z.enum(['keyword', 'match_only_text', 'long', 'double', 'date', 'boolean', 'ip']),
+  type: z.enum(['keyword', 'match_only_text', 'long', 'double', 'date', 'boolean', 'ip', 'alias']),
+  alias_path: z.optional(z.string()),
 });
 
 export type FieldDefinition = z.infer<typeof fieldDefinitionSchema>;

x-pack/plugins/streams/server/lib/streams/component_templates/generate_layer.ts

@@ -8,6 +8,7 @@
 import {
   ClusterPutComponentTemplateRequest,
   MappingDateProperty,
+  MappingFieldAliasProperty,
   MappingProperty,
 } from '@elastic/elasticsearch/lib/api/types';
 import { StreamDefinition } from '../../../../common/types';
@@ -18,7 +19,8 @@ import { getComponentTemplateName } from './name';
 
 export function generateLayer(
   id: string,
-  definition: StreamDefinition
+  definition: StreamDefinition,
+  rootDefinition: StreamDefinition | undefined
 ): ClusterPutComponentTemplateRequest {
   const properties: Record<string, MappingProperty> = {};
   definition.fields.forEach((field) => {
@@ -29,6 +31,18 @@ export function generateLayer(
       // @timestamp can't ignore malformed dates as it's used for sorting in logsdb
       (property as MappingDateProperty).ignore_malformed = false;
     }
+    if (field.type === 'alias' && field.alias_path) {
+      (property as MappingFieldAliasProperty).path = field.alias_path;
+      // try to find the referenced field in the root definition and add it here as well to satisfy the Elasticsearch alias checker
+      if (rootDefinition) {
+        const rootField = rootDefinition.fields.find((f) => f.name === field.alias_path);
+        if (rootField) {
+          properties[field.alias_path] = {
+            type: rootField.type,
+          };
+        }
+      }
+    }
     properties[field.name] = property;
   });
   return {

x-pack/plugins/streams/server/lib/streams/root_stream_definition.ts

@@ -21,10 +21,18 @@ export const rootStreamDefinition: StreamDefinition = {
       name: 'message',
       type: 'match_only_text',
     },
+    {
+      name: 'body.text',
+      type: 'match_only_text',
+    },
     {
       name: 'host.name',
       type: 'keyword',
     },
+    {
+      name: 'resource.attributes.host.name',
+      type: 'keyword',
+    },
     {
       name: 'log.level',
       type: 'keyword',

x-pack/plugins/streams/server/lib/streams/stream_crud.ts

@@ -369,6 +369,10 @@ export async function validateAncestorFields(
   });
   for (const ancestor of ancestors) {
     for (const field of fields) {
+      if (field.type === 'alias') {
+        // TODO: validate whether field under alias_path has the same type as an ancestor field definition of the current field
+        continue;
+      }
       if (
         ancestor.definition.fields.some(
           (ancestorField) => ancestorField.type !== field.type && ancestorField.name === field.name
@@ -455,7 +459,7 @@ export async function syncStream({
     });
     return;
   }
-  const componentTemplate = generateLayer(definition.id, definition);
+  const componentTemplate = generateLayer(definition.id, definition, rootDefinition);
   await upsertComponent({
     esClient: scopedClusterClient.asCurrentUser,
     logger,