Make DataSource beans application-scoped

So that we'll be able to postpone initialization to first access
in some cases, instead of doing it on startup.

This could be useful in particular for deactivated datasources:
we don't want to initialize those on startup, but we do want them
to fail on first use.

An alternative would have been to represent deactivated datasources
with a custom implementation of AgroalDataSource, like we currently do
with UnconfiguredDataSource, but that solution has serious problems,
in particular when we "forget" to implement some methods:
see quarkusio#36666

extensions/agroal/deployment/src/main/java/io/quarkus/agroal/deployment/AgroalProcessor.java

@@ -14,8 +14,8 @@
 
 import javax.sql.XADataSource;
 
+import jakarta.enterprise.context.ApplicationScoped;
 import jakarta.enterprise.inject.Default;
-import jakarta.inject.Singleton;
 
 import org.jboss.jandex.ClassType;
 import org.jboss.jandex.DotName;
@@ -72,6 +72,7 @@ class AgroalProcessor {
 
     private static final String OPEN_TELEMETRY_DRIVER = "io.opentelemetry.instrumentation.jdbc.OpenTelemetryDriver";
     private static final DotName DATA_SOURCE = DotName.createSimple(javax.sql.DataSource.class.getName());
+    private static final DotName AGROAL_DATA_SOURCE = DotName.createSimple(AgroalDataSource.class.getName());
 
     @BuildStep
     void agroal(BuildProducer<FeatureBuildItem> feature) {
@@ -277,7 +278,8 @@ void generateDataSourceBeans(AgroalRecorder recorder,
             SyntheticBeanBuildItem.ExtendedBeanConfigurator configurator = SyntheticBeanBuildItem
                     .configure(AgroalDataSource.class)
                     .addType(DATA_SOURCE)
-                    .scope(Singleton.class)
+                    .addType(AGROAL_DATA_SOURCE)
+                    .scope(ApplicationScoped.class)
                     .setRuntimeInit()
                     .unremovable()
                     .addInjectionPoint(ClassType.create(DotName.createSimple(DataSources.class)))

extensions/agroal/deployment/src/test/java/io/quarkus/agroal/test/EagerStartupTest.java

@@ -0,0 +1,41 @@
+package io.quarkus.agroal.test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import jakarta.inject.Singleton;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.RegisterExtension;
+
+import io.quarkus.agroal.runtime.DataSources;
+import io.quarkus.arc.Arc;
+import io.quarkus.datasource.common.runtime.DataSourceUtil;
+import io.quarkus.test.QuarkusUnitTest;
+
+/**
+ * Check that datasources are created eagerly on application startup.
+ * <p>
+ * This has always been the case historically, so we want to keep it that way.
+ */
+public class EagerStartupTest {
+
+    @RegisterExtension
+    static final QuarkusUnitTest config = new QuarkusUnitTest()
+            .withConfigurationResource("base.properties");
+
+    @Test
+    public void shouldStartEagerly() {
+        var container = Arc.container();
+        var instanceHandle = container.instance(DataSources.class);
+        // Check that the following call won't trigger a lazy initialization:
+        // the DataSources bean must be eagerly initialized.
+        assertThat(container.getActiveContext(Singleton.class).getState()
+                .getContextualInstances().get(instanceHandle.getBean()))
+                .as("Eagerly instantiated DataSources bean")
+                .isNotNull();
+        // Check that the datasource has already been eagerly created.
+        assertThat(instanceHandle.get().isDataSourceCreated(DataSourceUtil.DEFAULT_DATASOURCE_NAME))
+                .isTrue();
+    }
+
+}

extensions/agroal/runtime/src/main/java/io/quarkus/agroal/runtime/DataSources.java

@@ -13,6 +13,7 @@
 import java.util.function.Function;
 import java.util.stream.Collectors;
 
+import jakarta.annotation.PostConstruct;
 import jakarta.annotation.PreDestroy;
 import jakarta.enterprise.inject.Any;
 import jakarta.enterprise.inject.Default;
@@ -122,6 +123,10 @@ public static AgroalDataSource fromName(String dataSourceName) {
                 .getDataSource(dataSourceName);
     }
 
+    public boolean isDataSourceCreated(String dataSourceName) {
+        return dataSources.containsKey(dataSourceName);
+    }
+
     public AgroalDataSource getDataSource(String dataSourceName) {
         return dataSources.computeIfAbsent(dataSourceName, new Function<String, AgroalDataSource>() {
             @Override
@@ -131,6 +136,13 @@ public AgroalDataSource apply(String s) {
         });
     }
 
+    @PostConstruct
+    public void start() {
+        for (String dataSourceName : dataSourceSupport.entries.keySet()) {
+            getDataSource(dataSourceName);
+        }
+    }
+
     @SuppressWarnings("resource")
     public AgroalDataSource doCreateDataSource(String dataSourceName) {
         if (!dataSourceSupport.entries.containsKey(dataSourceName)) {

extensions/hibernate-orm/deployment/src/test/java/io/quarkus/hibernate/orm/config/datasource/EntitiesInDefaultPUWithImplicitUnconfiguredDatasourceTest.java

@@ -20,7 +20,7 @@ public class EntitiesInDefaultPUWithImplicitUnconfiguredDatasourceTest {
             .assertException(t -> assertThat(t)
                     .isInstanceOf(RuntimeException.class)
                     .hasMessageContainingAll(
-                            "Model classes are defined for the default persistence unit <default> but configured datasource <default> not found",
+                            "Model classes are defined for persistence unit <default> but configured datasource <default> not found",
                             "To solve this, configure the default datasource.",
                             "Refer to https://quarkus.io/guides/datasource for guidance."));
 

extensions/hibernate-orm/runtime/src/main/java/io/quarkus/hibernate/orm/runtime/FastBootHibernatePersistenceProvider.java

@@ -24,11 +24,9 @@
 import org.hibernate.service.internal.ProvidedService;
 import org.jboss.logging.Logger;
 
-import io.quarkus.agroal.DataSource.DataSourceLiteral;
+import io.quarkus.agroal.runtime.DataSources;
 import io.quarkus.agroal.runtime.UnconfiguredDataSource;
 import io.quarkus.arc.Arc;
-import io.quarkus.arc.InstanceHandle;
-import io.quarkus.datasource.common.runtime.DataSourceUtil;
 import io.quarkus.hibernate.orm.runtime.RuntimeSettings.Builder;
 import io.quarkus.hibernate.orm.runtime.boot.FastBootEntityManagerFactoryBuilder;
 import io.quarkus.hibernate.orm.runtime.boot.RuntimePersistenceUnitDescriptor;
@@ -38,7 +36,6 @@
 import io.quarkus.hibernate.orm.runtime.integration.HibernateOrmIntegrationRuntimeInitListener;
 import io.quarkus.hibernate.orm.runtime.recording.PrevalidatedQuarkusMetadata;
 import io.quarkus.hibernate.orm.runtime.recording.RecordedState;
-import io.quarkus.runtime.configuration.ConfigurationException;
 
 /**
  * This can not inherit from HibernatePersistenceProvider as that would force
@@ -375,7 +372,7 @@ private void verifyProperties(Map properties) {
         }
     }
 
-    private static void injectDataSource(String persistenceUnitName, String dataSource,
+    private static void injectDataSource(String persistenceUnitName, String dataSourceName,
             RuntimeSettings.Builder runtimeSettingsBuilder) {
         // first convert
 
@@ -389,26 +386,21 @@ private static void injectDataSource(String persistenceUnitName, String dataSour
             return;
         }
 
-        InstanceHandle<DataSource> dataSourceHandle;
-        if (DataSourceUtil.isDefault(dataSource)) {
-            dataSourceHandle = Arc.container().instance(DataSource.class);
-        } else {
-            dataSourceHandle = Arc.container().instance(DataSource.class, new DataSourceLiteral(dataSource));
-        }
-
-        if (!dataSourceHandle.isAvailable()) {
+        DataSource dataSource;
+        try {
+            dataSource = Arc.container().instance(DataSources.class).get().getDataSource(dataSourceName);
+        } catch (IllegalArgumentException e) {
             throw new IllegalStateException(
-                    "No datasource " + dataSource + " has been defined for persistence unit " + persistenceUnitName);
+                    "No datasource " + dataSourceName + " has been defined for persistence unit " + persistenceUnitName);
         }
 
-        DataSource ds = dataSourceHandle.get();
-        if (ds instanceof UnconfiguredDataSource) {
-            throw new ConfigurationException(
-                    "Model classes are defined for the default persistence unit " + persistenceUnitName
-                            + " but configured datasource " + dataSource
+        if (dataSource instanceof UnconfiguredDataSource) {
+            throw new IllegalStateException(
+                    "Model classes are defined for persistence unit " + persistenceUnitName
+                            + " but configured datasource " + dataSourceName
                             + " not found: the default EntityManagerFactory will not be created. To solve this, configure the default datasource. Refer to https://quarkus.io/guides/datasource for guidance.");
         }
-        runtimeSettingsBuilder.put(AvailableSettings.DATASOURCE, ds);
+        runtimeSettingsBuilder.put(AvailableSettings.DATASOURCE, dataSource);
     }
 
     private static void injectRuntimeConfiguration(HibernateOrmRuntimeConfigPersistenceUnit persistenceUnitConfig,