Add Mixedbread AI support

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

@@ -329,6 +329,7 @@ static TransportVersion def(int id) {
     public static final TransportVersion PROJECT_STATE_REGISTRY_RECORDS_DELETIONS = def(9_113_0_00);
     public static final TransportVersion ESQL_SERIALIZE_TIMESERIES_FIELD_TYPE = def(9_114_0_00);
     public static final TransportVersion ML_INFERENCE_IBM_WATSONX_COMPLETION_ADDED = def(9_115_0_00);
+    public static final TransportVersion ML_INFERENCE_MIXEDBREAD_ADDED = def(9_116_0_00);
     /*
      * STOP! READ THIS FIRST! No, really,
      *        ____ _____ ___  ____  _        ____  _____    _    ____    _____ _   _ ___ ____    _____ ___ ____  ____ _____ _

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

@@ -106,6 +106,10 @@
 import org.elasticsearch.xpack.inference.services.jinaai.rerank.JinaAIRerankTaskSettings;
 import org.elasticsearch.xpack.inference.services.mistral.completion.MistralChatCompletionServiceSettings;
 import org.elasticsearch.xpack.inference.services.mistral.embeddings.MistralEmbeddingsServiceSettings;
+import org.elasticsearch.xpack.inference.services.mixedbread.embeddings.MixedbreadEmbeddingsServiceSettings;
+import org.elasticsearch.xpack.inference.services.mixedbread.embeddings.MixedbreadEmbeddingsTaskSettings;
+import org.elasticsearch.xpack.inference.services.mixedbread.rerank.MixedbreadRerankServiceSettings;
+import org.elasticsearch.xpack.inference.services.mixedbread.rerank.MixedbreadRerankTaskSettings;
 import org.elasticsearch.xpack.inference.services.openai.completion.OpenAiChatCompletionServiceSettings;
 import org.elasticsearch.xpack.inference.services.openai.completion.OpenAiChatCompletionTaskSettings;
 import org.elasticsearch.xpack.inference.services.openai.embeddings.OpenAiEmbeddingsServiceSettings;
@@ -164,6 +168,7 @@ public static List<NamedWriteableRegistry.Entry> getNamedWriteables() {
         addIbmWatsonxNamedWritables(namedWriteables);
         addGoogleVertexAiNamedWriteables(namedWriteables);
         addMistralNamedWriteables(namedWriteables);
+        addMixedbreadNamedWriteables(namedWriteables);
         addCustomElandWriteables(namedWriteables);
         addAnthropicNamedWritables(namedWriteables);
         addAmazonBedrockNamedWriteables(namedWriteables);
@@ -276,6 +281,34 @@ private static void addMistralNamedWriteables(List<NamedWriteableRegistry.Entry>
         // note - no task settings for Mistral embeddings...
     }
 
+    private static void addMixedbreadNamedWriteables(List<NamedWriteableRegistry.Entry> namedWriteables) {
+        namedWriteables.add(
+            new NamedWriteableRegistry.Entry(
+                ServiceSettings.class,
+                MixedbreadEmbeddingsServiceSettings.NAME,
+                MixedbreadEmbeddingsServiceSettings::new
+            )
+        );
+        namedWriteables.add(
+            new NamedWriteableRegistry.Entry(
+                TaskSettings.class,
+                MixedbreadEmbeddingsTaskSettings.NAME,
+                MixedbreadEmbeddingsTaskSettings::new
+            )
+        );
+
+        namedWriteables.add(
+            new NamedWriteableRegistry.Entry(
+                ServiceSettings.class,
+                MixedbreadRerankServiceSettings.NAME,
+                MixedbreadRerankServiceSettings::new
+            )
+        );
+        namedWriteables.add(
+            new NamedWriteableRegistry.Entry(TaskSettings.class, MixedbreadRerankTaskSettings.NAME, MixedbreadRerankTaskSettings::new)
+        );
+    }
+
     private static void addAzureAiStudioNamedWriteables(List<NamedWriteableRegistry.Entry> namedWriteables) {
         namedWriteables.add(
             new NamedWriteableRegistry.Entry(

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

@@ -133,6 +133,7 @@
 import org.elasticsearch.xpack.inference.services.ibmwatsonx.IbmWatsonxService;
 import org.elasticsearch.xpack.inference.services.jinaai.JinaAIService;
 import org.elasticsearch.xpack.inference.services.mistral.MistralService;
+import org.elasticsearch.xpack.inference.services.mixedbread.MixedbreadService;
 import org.elasticsearch.xpack.inference.services.openai.OpenAiService;
 import org.elasticsearch.xpack.inference.services.sagemaker.SageMakerClient;
 import org.elasticsearch.xpack.inference.services.sagemaker.SageMakerService;
@@ -392,6 +393,7 @@ public List<InferenceServiceExtension.Factory> getInferenceServiceFactories() {
             context -> new GoogleAiStudioService(httpFactory.get(), serviceComponents.get()),
             context -> new GoogleVertexAiService(httpFactory.get(), serviceComponents.get()),
             context -> new MistralService(httpFactory.get(), serviceComponents.get()),
+            context -> new MixedbreadService(httpFactory.get(), serviceComponents.get()),
             context -> new AnthropicService(httpFactory.get(), serviceComponents.get()),
             context -> new AmazonBedrockService(httpFactory.get(), amazonBedrockFactory.get(), serviceComponents.get()),
             context -> new AlibabaCloudSearchService(httpFactory.get(), serviceComponents.get()),

x-pack/plugin/inference/src/main/java/org/elasticsearch/xpack/inference/services/mixedbread/MixedbreadConstants.java

@@ -0,0 +1,31 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0; you may not use this file except in compliance with the Elastic License
+ * 2.0.
+ */
+
+package org.elasticsearch.xpack.inference.services.mixedbread;
+
+public class MixedbreadConstants {
+    public static final String EMBEDDINGS_URI_PATH = "/v1/embeddings";
+    public static final String RERANK_URI_PATH = "/v1/rerank";
+
+    // common service settings fields
+    public static final String API_KEY_FIELD = "api_key";
+
+    // embeddings service and request settings
+    public static final String INPUT_FIELD = "input";
+
+    // rerank task settings fields
+    public static final String QUERY_FIELD = "query";
+
+    // embeddings task settings fields
+    public static final String USER_FIELD = "user";
+
+    // rerank task settings fields
+    public static final String RETURN_DOCUMENTS_FIELD = "return_documents";
+    public static final String TOP_K_FIELD = "top_k";
+
+    private MixedbreadConstants() {}
+}

x-pack/plugin/inference/src/main/java/org/elasticsearch/xpack/inference/services/mixedbread/MixedbreadModel.java

@@ -0,0 +1,101 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0; you may not use this file except in compliance with the Elastic License
+ * 2.0.
+ */
+
+package org.elasticsearch.xpack.inference.services.mixedbread;
+
+import org.elasticsearch.inference.EmptySecretSettings;
+import org.elasticsearch.inference.ModelConfigurations;
+import org.elasticsearch.inference.ModelSecrets;
+import org.elasticsearch.inference.SecretSettings;
+import org.elasticsearch.inference.ServiceSettings;
+import org.elasticsearch.inference.TaskSettings;
+import org.elasticsearch.xpack.inference.services.RateLimitGroupingModel;
+import org.elasticsearch.xpack.inference.services.settings.DefaultSecretSettings;
+import org.elasticsearch.xpack.inference.services.settings.RateLimitSettings;
+
+import java.net.URI;
+import java.net.URISyntaxException;
+import java.util.Map;
+import java.util.Objects;
+
+/**
+ * Abstract class representing a Mixedbread model for inference.
+ * This class extends RateLimitGroupingModel and provides common functionality for Mixedbread models.
+ */
+public abstract class MixedbreadModel extends RateLimitGroupingModel {
+    protected String modelId;
+    protected URI uri;
+    protected RateLimitSettings rateLimitSettings;
+
+    public MixedbreadModel(MixedbreadModel model, TaskSettings taskSettings, RateLimitSettings rateLimitSettings) {
+        super(model, taskSettings);
+        this.rateLimitSettings = Objects.requireNonNull(rateLimitSettings);
+    }
+
+    /**
+     * Constructor for creating a MixedbreadModel with specified configurations and secrets.
+     *
+     * @param configurations the model configurations
+     * @param secrets the secret settings for the model
+     */
+    protected MixedbreadModel(ModelConfigurations configurations, ModelSecrets secrets) {
+        super(configurations, secrets);
+    }
+
+    /**
+     * Constructor for creating a MixedbreadModel with specified model, service settings, and secret settings.
+     * @param model the model configurations
+     * @param serviceSettings the settings for the inference service
+     */
+    protected MixedbreadModel(RateLimitGroupingModel model, ServiceSettings serviceSettings) {
+        super(model, serviceSettings);
+    }
+
+    public String model() {
+        return this.modelId;
+    }
+
+    public URI uri() {
+        return this.uri;
+    }
+
+    @Override
+    public RateLimitSettings rateLimitSettings() {
+        return this.rateLimitSettings;
+    }
+
+    @Override
+    public int rateLimitGroupingHash() {
+        return Objects.hash(modelId, uri, getSecretSettings());
+    }
+
+    // Needed for testing only
+    public void setURI(String newUri) {
+        try {
+            this.uri = new URI(newUri);
+        } catch (URISyntaxException e) {
+            // swallow any error
+        }
+    }
+
+    /**
+     * Retrieves the secret settings from the provided map of secrets.
+     * If the map is null or empty, it returns an instance of EmptySecretSettings.
+     * Caused by the fact that Mixedbread model doesn't have out of the box security settings and can be used witout authentication.
+     *
+     * @param secrets the map containing secret settings
+     * @return an instance of SecretSettings
+     */
+    protected static SecretSettings retrieveSecretSettings(Map<String, Object> secrets) {
+        return (secrets != null && secrets.isEmpty()) ? EmptySecretSettings.INSTANCE : DefaultSecretSettings.fromMap(secrets);
+    }
+
+    @Override
+    public DefaultSecretSettings getSecretSettings() {
+        return (DefaultSecretSettings) super.getSecretSettings();
+    }
+}