[Inference API] Default eis endpoint

docs/changelog/119694.yaml

@@ -0,0 +1,5 @@
+pr: 119694
+summary: "[Inference API] Add default endpoint for completion in elastic inference service"
+area: Machine Learning
+type: enhancement
+issues: []

x-pack/plugin/inference/qa/inference-service-tests/src/javaRestTest/java/org/elasticsearch/xpack/inference/InferenceCrudIT.java

@@ -35,7 +35,6 @@
 import java.util.stream.Stream;
 
 import static org.hamcrest.Matchers.containsString;
-import static org.hamcrest.Matchers.empty;
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.equalToIgnoringCase;
 import static org.hamcrest.Matchers.hasSize;
@@ -58,7 +57,7 @@ public void testCRUD() throws IOException {
         }
 
         var getAllModels = getAllModels();
-        int numModels = 12;
+        int numModels = 13;
         assertThat(getAllModels, hasSize(numModels));
 
         var getSparseModels = getModels("_all", TaskType.SPARSE_EMBEDDING);
@@ -543,8 +542,8 @@ private static String expectedResult(String input) {
         }
     }
 
-    public void testGetZeroModels() throws IOException {
+    public void testGetCompletionModels() throws IOException {
         var models = getModels("_all", TaskType.COMPLETION);
-        assertThat(models, empty());
+        assertEquals(models.size(), 1);
     }
 }

x-pack/plugin/inference/src/main/java/org/elasticsearch/xpack/inference/services/elastic/ElasticInferenceService.java

@@ -72,6 +72,10 @@ public class ElasticInferenceService extends SenderService {
     private static final EnumSet<TaskType> supportedTaskTypes = EnumSet.of(TaskType.SPARSE_EMBEDDING, TaskType.COMPLETION);
     private static final String SERVICE_NAME = "Elastic";
 
+    public static final String DEFAULT_EIS_COMPLETION_ENDPOINT_ID_V1 = ".eis-alpha-1";
+
+    public static final List<String> DEFAULT_EIS_ENDPOINT_IDS = List.of(DEFAULT_EIS_COMPLETION_ENDPOINT_ID_V1);
+
     public ElasticInferenceService(
         HttpRequestSender.Factory factory,
         ServiceComponents serviceComponents,
@@ -175,6 +179,17 @@ public void parseRequestConfig(
         Map<String, Object> config,
         ActionListener<Model> parsedModelListener
     ) {
+        if (DEFAULT_EIS_ENDPOINT_IDS.contains(inferenceEntityId)) {
+            parsedModelListener.onFailure(
+                new ElasticsearchStatusException(
+                    "[{}] is a reserved inference Id. Cannot create a new inference endpoint with a reserved Id",
+                    RestStatus.BAD_REQUEST,
+                    inferenceEntityId
+                )
+            );
+            return;
+        }
+
         try {
             Map<String, Object> serviceSettingsMap = removeFromMapOrThrowIfNull(config, ModelConfigurations.SERVICE_SETTINGS);
             Map<String, Object> taskSettingsMap = removeFromMapOrDefaultEmpty(config, ModelConfigurations.TASK_SETTINGS);
@@ -210,6 +225,32 @@ public EnumSet<TaskType> supportedTaskTypes() {
         return supportedTaskTypes;
     }
 
+    @Override
+    public List<DefaultConfigId> defaultConfigIds() {
+        return List.of(new DefaultConfigId(DEFAULT_EIS_COMPLETION_ENDPOINT_ID_V1, TaskType.COMPLETION, this));
+    }
+
+    @Override
+    public void defaultConfigs(ActionListener<List<Model>> defaultsListener) {
+        defaultsListener.onResponse(List.of(firstDefaultCompletionModel()));
+    }
+
+    private ElasticInferenceServiceCompletionModel firstDefaultCompletionModel() {
+        var serviceSettings = new HashMap<String, Object>(1);
+        serviceSettings.put(MODEL_ID, "elastic-model"); // TODO
+
+        return new ElasticInferenceServiceCompletionModel(
+            DEFAULT_EIS_COMPLETION_ENDPOINT_ID_V1,
+            TaskType.COMPLETION,
+            NAME,
+            serviceSettings,
+            null,
+            null,
+            elasticInferenceServiceComponents,
+            ConfigurationParseContext.PERSISTENT
+        );
+    }
+
     private static ElasticInferenceServiceModel createModel(
         String inferenceEntityId,
         TaskType taskType,

x-pack/plugin/inference/src/main/java/org/elasticsearch/xpack/inference/services/elastic/ElasticInferenceServiceSettings.java

@@ -35,7 +35,6 @@ public class ElasticInferenceServiceSettings {
     public ElasticInferenceServiceSettings(Settings settings) {
         eisGatewayUrl = EIS_GATEWAY_URL.get(settings);
         elasticInferenceServiceUrl = ELASTIC_INFERENCE_SERVICE_URL.get(settings);
-
     }
 
     public static List<Setting<?>> getSettingsDefinitions() {

x-pack/plugin/inference/src/main/java/org/elasticsearch/xpack/inference/services/elastic/completion/ElasticInferenceServiceCompletionModel.java

@@ -74,7 +74,7 @@ public ElasticInferenceServiceCompletionModel(
 
     }
 
-    ElasticInferenceServiceCompletionModel(
+    public ElasticInferenceServiceCompletionModel(
         String inferenceEntityId,
         TaskType taskType,
         String service,