[ML] Adding configurable inference service

docs/changelog/127939.yaml

@@ -0,0 +1,5 @@
+pr: 127939
+summary: Add Custom inference service
+area: Machine Learning
+type: enhancement
+issues: []

server/src/main/java/org/elasticsearch/TransportVersions.java

@@ -177,6 +177,7 @@ static TransportVersion def(int id) {
     public static final TransportVersion ESQL_DRIVER_TASK_DESCRIPTION_8_19 = def(8_841_0_30);
     public static final TransportVersion ML_INFERENCE_HUGGING_FACE_CHAT_COMPLETION_ADDED_8_19 = def(8_841_0_31);
     public static final TransportVersion V_8_19_FIELD_CAPS_ADD_CLUSTER_ALIAS = def(8_841_0_32);
+    public static final TransportVersion ADD_INFERENCE_CUSTOM_MODEL_8_19 = def(8_841_0_33);
     public static final TransportVersion V_9_0_0 = def(9_000_0_09);
     public static final TransportVersion INITIAL_ELASTICSEARCH_9_0_1 = def(9_000_0_10);
     public static final TransportVersion INITIAL_ELASTICSEARCH_9_0_2 = def(9_000_0_11);
@@ -258,6 +259,7 @@ static TransportVersion def(int id) {
     public static final TransportVersion ESQL_TIME_SERIES_SOURCE_STATUS = def(9_076_0_00);
     public static final TransportVersion ESQL_HASH_OPERATOR_STATUS_OUTPUT_TIME = def(9_077_0_00);
     public static final TransportVersion ML_INFERENCE_HUGGING_FACE_CHAT_COMPLETION_ADDED = def(9_078_0_00);
+    public static final TransportVersion ADD_INFERENCE_CUSTOM_MODEL = def(9_079_0_00);
 
     /*
      * STOP! READ THIS FIRST! No, really,

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

@@ -25,7 +25,7 @@ public class InferenceGetServicesIT extends BaseMockEISAuthServerTest {
 
     public void testGetServicesWithoutTaskType() throws IOException {
         List<Object> services = getAllServices();
-        assertThat(services.size(), equalTo(22));
+        assertThat(services.size(), equalTo(23));
 
         var providers = providers(services);
 
@@ -39,6 +39,7 @@ public void testGetServicesWithoutTaskType() throws IOException {
                     "azureaistudio",
                     "azureopenai",
                     "cohere",
+                    "custom",
                     "deepseek",
                     "elastic",
                     "elasticsearch",
@@ -70,7 +71,7 @@ private Iterable<String> providers(List<Object> services) {
 
     public void testGetServicesWithTextEmbeddingTaskType() throws IOException {
         List<Object> services = getServices(TaskType.TEXT_EMBEDDING);
-        assertThat(services.size(), equalTo(16));
+        assertThat(services.size(), equalTo(17));
 
         var providers = providers(services);
 
@@ -83,6 +84,7 @@ public void testGetServicesWithTextEmbeddingTaskType() throws IOException {
                     "azureaistudio",
                     "azureopenai",
                     "cohere",
+                    "custom",
                     "elasticsearch",
                     "googleaistudio",
                     "googlevertexai",
@@ -101,7 +103,7 @@ public void testGetServicesWithTextEmbeddingTaskType() throws IOException {
 
     public void testGetServicesWithRerankTaskType() throws IOException {
         List<Object> services = getServices(TaskType.RERANK);
-        assertThat(services.size(), equalTo(7));
+        assertThat(services.size(), equalTo(8));
 
         var providers = providers(services);
 
@@ -111,6 +113,7 @@ public void testGetServicesWithRerankTaskType() throws IOException {
                 List.of(
                     "alibabacloud-ai-search",
                     "cohere",
+                    "custom",
                     "elasticsearch",
                     "googlevertexai",
                     "jinaai",
@@ -123,7 +126,7 @@ public void testGetServicesWithRerankTaskType() throws IOException {
 
     public void testGetServicesWithCompletionTaskType() throws IOException {
         List<Object> services = getServices(TaskType.COMPLETION);
-        assertThat(services.size(), equalTo(11));
+        assertThat(services.size(), equalTo(12));
 
         var providers = providers(services);
 
@@ -137,6 +140,7 @@ public void testGetServicesWithCompletionTaskType() throws IOException {
                     "azureaistudio",
                     "azureopenai",
                     "cohere",
+                    "custom",
                     "deepseek",
                     "googleaistudio",
                     "openai",
@@ -161,7 +165,7 @@ public void testGetServicesWithChatCompletionTaskType() throws IOException {
 
     public void testGetServicesWithSparseEmbeddingTaskType() throws IOException {
         List<Object> services = getServices(TaskType.SPARSE_EMBEDDING);
-        assertThat(services.size(), equalTo(6));
+        assertThat(services.size(), equalTo(7));
 
         var providers = providers(services);
 
@@ -170,6 +174,7 @@ public void testGetServicesWithSparseEmbeddingTaskType() throws IOException {
             containsInAnyOrder(
                 List.of(
                     "alibabacloud-ai-search",
+                    "custom",
                     "elastic",
                     "elasticsearch",
                     "hugging_face",

x-pack/plugin/inference/src/main/java/org/elasticsearch/xpack/inference/InferenceNamedWriteablesProvider.java

@@ -59,6 +59,15 @@
 import org.elasticsearch.xpack.inference.services.cohere.embeddings.CohereEmbeddingsTaskSettings;
 import org.elasticsearch.xpack.inference.services.cohere.rerank.CohereRerankServiceSettings;
 import org.elasticsearch.xpack.inference.services.cohere.rerank.CohereRerankTaskSettings;
+import org.elasticsearch.xpack.inference.services.custom.CustomSecretSettings;
+import org.elasticsearch.xpack.inference.services.custom.CustomServiceSettings;
+import org.elasticsearch.xpack.inference.services.custom.CustomTaskSettings;
+import org.elasticsearch.xpack.inference.services.custom.response.CompletionResponseParser;
+import org.elasticsearch.xpack.inference.services.custom.response.CustomResponseParser;
+import org.elasticsearch.xpack.inference.services.custom.response.NoopResponseParser;
+import org.elasticsearch.xpack.inference.services.custom.response.RerankResponseParser;
+import org.elasticsearch.xpack.inference.services.custom.response.SparseEmbeddingResponseParser;
+import org.elasticsearch.xpack.inference.services.custom.response.TextEmbeddingResponseParser;
 import org.elasticsearch.xpack.inference.services.deepseek.DeepSeekChatCompletionModel;
 import org.elasticsearch.xpack.inference.services.elastic.completion.ElasticInferenceServiceCompletionServiceSettings;
 import org.elasticsearch.xpack.inference.services.elastic.sparseembeddings.ElasticInferenceServiceSparseEmbeddingsServiceSettings;
@@ -155,6 +164,7 @@ public static List<NamedWriteableRegistry.Entry> getNamedWriteables() {
         addAlibabaCloudSearchNamedWriteables(namedWriteables);
         addJinaAINamedWriteables(namedWriteables);
         addVoyageAINamedWriteables(namedWriteables);
+        addCustomNamedWriteables(namedWriteables);
 
         addUnifiedNamedWriteables(namedWriteables);
 
@@ -166,6 +176,38 @@ public static List<NamedWriteableRegistry.Entry> getNamedWriteables() {
         return namedWriteables;
     }
 
+    private static void addCustomNamedWriteables(List<NamedWriteableRegistry.Entry> namedWriteables) {
+        namedWriteables.add(
+            new NamedWriteableRegistry.Entry(ServiceSettings.class, CustomServiceSettings.NAME, CustomServiceSettings::new)
+        );
+
+        namedWriteables.add(new NamedWriteableRegistry.Entry(TaskSettings.class, CustomTaskSettings.NAME, CustomTaskSettings::new));
+
+        namedWriteables.add(new NamedWriteableRegistry.Entry(SecretSettings.class, CustomSecretSettings.NAME, CustomSecretSettings::new));
+
+        namedWriteables.add(
+            new NamedWriteableRegistry.Entry(CustomResponseParser.class, TextEmbeddingResponseParser.NAME, TextEmbeddingResponseParser::new)
+        );
+
+        namedWriteables.add(
+            new NamedWriteableRegistry.Entry(
+                CustomResponseParser.class,
+                SparseEmbeddingResponseParser.NAME,
+                SparseEmbeddingResponseParser::new
+            )
+        );
+
+        namedWriteables.add(
+            new NamedWriteableRegistry.Entry(CustomResponseParser.class, RerankResponseParser.NAME, RerankResponseParser::new)
+        );
+
+        namedWriteables.add(new NamedWriteableRegistry.Entry(CustomResponseParser.class, NoopResponseParser.NAME, NoopResponseParser::new));
+
+        namedWriteables.add(
+            new NamedWriteableRegistry.Entry(CustomResponseParser.class, CompletionResponseParser.NAME, CompletionResponseParser::new)
+        );
+    }
+
     private static void addUnifiedNamedWriteables(List<NamedWriteableRegistry.Entry> namedWriteables) {
         var writeables = UnifiedCompletionRequest.getNamedWriteables();
         namedWriteables.addAll(writeables);

x-pack/plugin/inference/src/main/java/org/elasticsearch/xpack/inference/InferencePlugin.java

@@ -119,6 +119,7 @@
 import org.elasticsearch.xpack.inference.services.azureaistudio.AzureAiStudioService;
 import org.elasticsearch.xpack.inference.services.azureopenai.AzureOpenAiService;
 import org.elasticsearch.xpack.inference.services.cohere.CohereService;
+import org.elasticsearch.xpack.inference.services.custom.CustomService;
 import org.elasticsearch.xpack.inference.services.deepseek.DeepSeekService;
 import org.elasticsearch.xpack.inference.services.elastic.ElasticInferenceService;
 import org.elasticsearch.xpack.inference.services.elastic.ElasticInferenceServiceComponents;
@@ -396,6 +397,7 @@ public List<InferenceServiceExtension.Factory> getInferenceServiceFactories() {
             context -> new JinaAIService(httpFactory.get(), serviceComponents.get()),
             context -> new VoyageAIService(httpFactory.get(), serviceComponents.get()),
             context -> new DeepSeekService(httpFactory.get(), serviceComponents.get()),
+            context -> new CustomService(httpFactory.get(), serviceComponents.get()),
             ElasticsearchInternalService::new
         );
     }

x-pack/plugin/inference/src/main/java/org/elasticsearch/xpack/inference/external/http/retry/BaseResponseHandler.java

@@ -36,7 +36,7 @@ public abstract class BaseResponseHandler implements ResponseHandler {
     public static final String METHOD_NOT_ALLOWED = "Received a method not allowed status code";
 
     protected final String requestType;
-    private final ResponseParser parseFunction;
+    protected final ResponseParser parseFunction;
     private final Function<HttpResult, ErrorResponse> errorParseFunction;
     private final boolean canHandleStreamingResponses;