Add model registry to semantic query builder

Author: Mikep86

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

@@ -592,10 +592,11 @@ public Map<String, Highlighter> getHighlighters() {
     @Override
     public void onNodeStarted() {
         var registry = inferenceServiceRegistry.get();
-
         if (registry != null) {
             registry.onNodeStarted();
         }
+
+        SemanticQueryBuilder.setModelRegistrySupplier(getModelRegistry());
     }
 
     @Override

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

@@ -36,12 +36,14 @@
 import org.elasticsearch.xpack.core.ml.inference.results.TextExpansionResults;
 import org.elasticsearch.xpack.core.ml.inference.results.WarningInferenceResults;
 import org.elasticsearch.xpack.inference.mapper.SemanticTextFieldMapper;
+import org.elasticsearch.xpack.inference.registry.ModelRegistry;
 
 import java.io.IOException;
 import java.util.Collection;
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
+import java.util.function.Supplier;
 
 import static org.elasticsearch.xcontent.ConstructingObjectParser.constructorArg;
 import static org.elasticsearch.xcontent.ConstructingObjectParser.optionalConstructorArg;
@@ -68,6 +70,12 @@ public class SemanticQueryBuilder extends AbstractQueryBuilder<SemanticQueryBuil
         declareStandardFields(PARSER);
     }
 
+    private static Supplier<ModelRegistry> MODEL_REGISTRY_SUPPLIER = () -> null;
+
+    public static void setModelRegistrySupplier(Supplier<ModelRegistry> supplier) {
+        MODEL_REGISTRY_SUPPLIER = supplier;
+    }
+
     private final String fieldName;
     private final String query;
     private final SetOnce<InferenceServiceResults> inferenceResultsSupplier;