[eem] metadata as keyword (elastic#202611)

Cast identity fields and metadata fields as keyword to prevent ambiguous
mappings error

### Testing

- setup data
```
PUT service-name-as-keyword
{
    "mappings": {
        "dynamic": false,
        "properties": {
            "service.name": {
                "type": "keyword"
            }
        }
    }
}

POST service-name-as-keyword/_doc
{
  "service.name": "as-keyword"
}

PUT service-name-as-text
{
    "mappings": {
        "dynamic": false,
        "properties": {
            "service.name": {
                "type": "text"
            }
        }
    }
}


POST service-name-as-text/_doc
{
  "service.name": "as-text"
}
```

- data loads successfully in `/app/entity_manager`
![Screenshot 2024-12-03 at 11 50
10](https://github.com/user-attachments/assets/12d6cbd8-c075-475f-b140-9158e93158ff)

_new query_
```
POST _query
{
    "query": """FROM service-name-as* | WHERE service.name::keyword IS NOT NULL | STATS  BY service.name::keyword | RENAME `service.name::keyword` AS service.name | EVAL entity.type = "service", entity.id = service.name, entity.display_name = entity.id | SORT entity.id ASC | LIMIT 10"""
}
```

- previous query fails with ambiguous mappings error
```
POST _query
{
    "query": """FROM service-name-as* | WHERE service.name IS NOT NULL | STATS  BY service.name | EVAL entity.type = "service", entity.id = service.name, entity.display_name = entity.id | SORT entity.id ASC | LIMIT 10"""
}
```

x-pack/plugins/entity_manager/server/lib/v2/queries/index.test.ts

@@ -29,9 +29,10 @@ describe('getEntityInstancesQuery', () => {
 
       expect(query).toEqual(
         'FROM logs-*, metrics-* | ' +
-          'WHERE service.name IS NOT NULL | ' +
+          'WHERE service.name::keyword IS NOT NULL | ' +
           'WHERE custom_timestamp_field >= "2024-11-20T19:00:00.000Z" AND custom_timestamp_field <= "2024-11-20T20:00:00.000Z" | ' +
-          'STATS host.name = VALUES(host.name), entity.last_seen_timestamp = MAX(custom_timestamp_field), service.id = MAX(service.id) BY service.name | ' +
+          'STATS host.name = VALUES(host.name::keyword), entity.last_seen_timestamp = MAX(custom_timestamp_field), service.id = MAX(service.id::keyword) BY service.name::keyword | ' +
+          'RENAME `service.name::keyword` AS service.name | ' +
           'EVAL entity.type = "service", entity.id = service.name, entity.display_name = COALESCE(service.id, entity.id) | ' +
           'SORT entity.id DESC | ' +
           'LIMIT 5'

x-pack/plugins/entity_manager/server/lib/v2/queries/index.ts

@@ -5,6 +5,7 @@
  * 2.0.
  */
 
+import { asKeyword } from './utils';
 import { EntitySourceDefinition, SortBy } from '../types';
 
 const sourceCommand = ({ source }: { source: EntitySourceDefinition }) => {
@@ -30,7 +31,7 @@ const whereCommand = ({
   end: string;
 }) => {
   const filters = [
-    source.identity_fields.map((field) => `${field} IS NOT NULL`).join(' AND '),
+    source.identity_fields.map((field) => `${asKeyword(field)} IS NOT NULL`).join(' AND '),
     ...source.filters,
   ];
 
@@ -46,7 +47,7 @@ const whereCommand = ({
 const statsCommand = ({ source }: { source: EntitySourceDefinition }) => {
   const aggs = source.metadata_fields
     .filter((field) => !source.identity_fields.some((idField) => idField === field))
-    .map((field) => `${field} = VALUES(${field})`);
+    .map((field) => `${field} = VALUES(${asKeyword(field)})`);
 
   if (source.timestamp_field) {
     aggs.push(`entity.last_seen_timestamp = MAX(${source.timestamp_field})`);
@@ -55,10 +56,15 @@ const statsCommand = ({ source }: { source: EntitySourceDefinition }) => {
   if (source.display_name) {
     // ideally we want the latest value but there's no command yet
     // so we use MAX for now
-    aggs.push(`${source.display_name} = MAX(${source.display_name})`);
+    aggs.push(`${source.display_name} = MAX(${asKeyword(source.display_name)})`);
   }
 
-  return `STATS ${aggs.join(', ')} BY ${source.identity_fields.join(', ')}`;
+  return `STATS ${aggs.join(', ')} BY ${source.identity_fields.map(asKeyword).join(', ')}`;
+};
+
+const renameCommand = ({ source }: { source: EntitySourceDefinition }) => {
+  const operations = source.identity_fields.map((field) => `\`${asKeyword(field)}\` AS ${field}`);
+  return `RENAME ${operations.join(', ')}`;
 };
 
 const evalCommand = ({ source }: { source: EntitySourceDefinition }) => {
@@ -107,6 +113,7 @@ export function getEntityInstancesQuery({
     sourceCommand({ source }),
     whereCommand({ source, start, end }),
     statsCommand({ source }),
+    renameCommand({ source }),
     evalCommand({ source }),
     sortCommand({ source, sort }),
     `LIMIT ${limit}`,

x-pack/plugins/entity_manager/server/lib/v2/queries/utils.ts

@@ -65,3 +65,7 @@ export function mergeEntitiesList(
 
   return Object.values(instances);
 }
+
+export function asKeyword(field: string) {
+  return `${field}::keyword`;
+}