Elastic as pinned provider (#208133)

## Summary

The Inference Service team is expecting `Elastic` service as a pinned
service in the provider list.




https://github.com/user-attachments/assets/e919d9ea-ebfa-4388-8125-c11c26199c54


### Checklist

Check the PR satisfies following conditions. 

Reviewers should verify this PR satisfies this list as well.

- [X] [Unit or functional
tests](https://www.elastic.co/guide/en/kibana/master/development-tests.html)
were updated or added to match the most common scenarios
- [ ] The PR description includes the appropriate Release Notes section,
and the correct `release_note:*` label is applied per the
[guidelines](https://www.elastic.co/guide/en/kibana/master/contributing.html#kibana-release-notes-process)

x-pack/platform/packages/shared/kbn-inference-endpoint-ui-common/src/components/inference_service_form_fields.test.tsx

@@ -56,6 +56,18 @@ describe('Inference Services', () => {
     expect(screen.getByTestId('euiSelectableList')).toBeInTheDocument();
   });
 
+  it('renders Elastic at top', async () => {
+    render(
+      <MockFormProvider>
+        <InferenceServiceFormFields http={httpMock} toasts={notificationsMock.toasts} />
+      </MockFormProvider>
+    );
+
+    await userEvent.click(screen.getByTestId('provider-select'));
+    const listItems = screen.getAllByTestId('provider');
+    expect(listItems[0]).toHaveTextContent('Elastic');
+  });
+
   it('renders selected provider fields - hugging_face', async () => {
     render(
       <MockFormProvider>

x-pack/platform/packages/shared/kbn-inference-endpoint-ui-common/src/components/inference_service_form_fields.tsx

@@ -28,7 +28,7 @@ import { ConnectorFormSchema } from '@kbn/triggers-actions-ui-plugin/public';
 
 import { HttpSetup, IToasts } from '@kbn/core/public';
 import * as LABELS from '../translations';
-import { Config, ConfigEntryView, Secrets } from '../types/types';
+import { Config, ConfigEntryView, InferenceProvider, Secrets } from '../types/types';
 import { SERVICE_PROVIDERS } from './providers/render_service_provider/service_provider';
 import { DEFAULT_TASK_TYPE, ServiceProviderKeys } from '../constants';
 import { SelectableProvider } from './providers/selectable';
@@ -56,6 +56,9 @@ export const InferenceServiceFormFields: React.FC<InferenceServicesProps> = ({
   isEdit,
 }) => {
   const { data: providers, isLoading } = useProviders(http, toasts);
+  const [updatedProviders, setUpdatedProviders] = useState<InferenceProvider[] | undefined>(
+    undefined
+  );
   const [isProviderPopoverOpen, setProviderPopoverOpen] = useState(false);
   const [providerSchema, setProviderSchema] = useState<ConfigEntryView[]>([]);
   const [taskTypeOptions, setTaskTypeOptions] = useState<TaskTypeOption[]>([]);
@@ -117,7 +120,7 @@ export const InferenceServiceFormFields: React.FC<InferenceServicesProps> = ({
         taskType,
       });
 
-      const newProvider = providers?.find(
+      const newProvider = updatedProviders?.find(
         (p) => p.service === (config.provider === '' ? providerSelected : config.provider)
       );
       if (newProvider) {
@@ -152,12 +155,12 @@ export const InferenceServiceFormFields: React.FC<InferenceServicesProps> = ({
         },
       });
     },
-    [config, providers, secrets, updateFieldValues]
+    [config, secrets, updateFieldValues, updatedProviders]
   );
 
   const onProviderChange = useCallback(
     (provider?: string) => {
-      const newProvider = providers?.find((p) => p.service === provider);
+      const newProvider = updatedProviders?.find((p) => p.service === provider);
 
       setTaskTypeOptions(getTaskTypeOptions(newProvider?.task_types ?? []));
       if (newProvider?.task_types && newProvider?.task_types.length > 0) {
@@ -202,7 +205,7 @@ export const InferenceServiceFormFields: React.FC<InferenceServicesProps> = ({
         },
       });
     },
-    [config, onTaskTypeOptionsSelect, providers, updateFieldValues]
+    [config, onTaskTypeOptionsSelect, updateFieldValues, updatedProviders]
   );
 
   const onSetProviderConfigEntry = useCallback(
@@ -281,9 +284,23 @@ export const InferenceServiceFormFields: React.FC<InferenceServicesProps> = ({
     ]
   );
 
+  useEffect(() => {
+    if (providers) {
+      // Ensure the Elastic Inference Service (EIS) appears at the top of the providers list
+      const elasticServiceIndex = providers.findIndex((provider) => provider.service === 'elastic');
+      if (elasticServiceIndex !== -1) {
+        const elasticService = providers[elasticServiceIndex];
+        const remainingProviders = providers.filter((_, index) => index !== elasticServiceIndex);
+        setUpdatedProviders([elasticService, ...remainingProviders]);
+      } else {
+        setUpdatedProviders(providers);
+      }
+    }
+  }, [providers]);
+
   useEffect(() => {
     if (config?.provider && config?.taskType && isEdit) {
-      const newProvider = providers?.find((p) => p.service === config.provider);
+      const newProvider = updatedProviders?.find((p) => p.service === config.provider);
       // Update connector providerSchema
 
       const newProviderSchema: ConfigEntryView[] = newProvider
@@ -294,7 +311,7 @@ export const InferenceServiceFormFields: React.FC<InferenceServicesProps> = ({
       }
       setSelectedTaskType(config.taskType);
     }
-  }, [config, config?.provider, config?.taskType, isEdit, providers, selectedTaskType]);
+  }, [config, config?.provider, config?.taskType, isEdit, selectedTaskType, updatedProviders]);
 
   useEffect(() => {
     if (isSubmitting) {
@@ -377,7 +394,7 @@ export const InferenceServiceFormFields: React.FC<InferenceServicesProps> = ({
                 className="rightArrowIcon"
               >
                 <SelectableProvider
-                  providers={providers ?? []}
+                  providers={updatedProviders ?? []}
                   onClosePopover={closeProviderPopover}
                   onProviderChange={onProviderChange}
                 />

x-pack/platform/packages/shared/kbn-inference-endpoint-ui-common/src/utils/mock_providers.ts

@@ -110,6 +110,43 @@ export const mockProviders: InferenceProvider[] = [
       },
     },
   },
+  {
+    service: 'elastic',
+    name: 'Elastic',
+    task_types: ['sparse_embedding', 'chat_completion'],
+    configurations: {
+      'rate_limit.requests_per_minute': {
+        default_value: null,
+        description: 'Minimize the number of rate limit errors.',
+        label: 'Rate Limit',
+        required: false,
+        sensitive: false,
+        updatable: false,
+        type: FieldType.INTEGER,
+        supported_task_types: ['sparse_embedding', 'chat_completion'],
+      },
+      model_id: {
+        default_value: null,
+        description: 'The name of the model to use for the inference task.',
+        label: 'Model ID',
+        required: true,
+        sensitive: false,
+        updatable: false,
+        type: FieldType.STRING,
+        supported_task_types: ['sparse_embedding', 'chat_completion'],
+      },
+      max_input_tokens: {
+        default_value: null,
+        description: 'Allows you to specify the maximum number of tokens per input.',
+        label: 'Maximum Input Tokens',
+        required: false,
+        sensitive: false,
+        updatable: false,
+        type: FieldType.INTEGER,
+        supported_task_types: ['sparse_embedding'],
+      },
+    },
+  },
   {
     service: 'elasticsearch',
     name: 'Elasticsearch',