Add support for multiple flyway instances

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/flyway/FlywayInstance.java

@@ -0,0 +1,28 @@
+/*
+ * Copyright 2012-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.autoconfigure.flyway;
+
+import java.lang.annotation.*;
+
+@Target({ElementType.METHOD, ElementType.ANNOTATION_TYPE,ElementType.TYPE})
+@Retention(RetentionPolicy.RUNTIME)
+@Documented
+public @interface FlywayInstance {
+
+	String value() default "";
+
+}

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/flyway/FlywayInstancesProperties.java

@@ -0,0 +1,37 @@
+/*
+ * Copyright 2012-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.autoconfigure.flyway;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import org.springframework.boot.context.properties.ConfigurationProperties;
+
+@ConfigurationProperties(prefix = "spring.flyway")
+public class FlywayInstancesProperties extends FlywayProperties {
+
+	private Map<String, FlywayProperties> instances = new HashMap<>();
+
+	public Map<String, FlywayProperties> getInstances() {
+		return this.instances;
+	}
+
+	public void setInstances(Map<String, FlywayProperties> instances) {
+		this.instances = instances;
+	}
+
+}

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/flyway/FlywayInstancesRegistrar.java

@@ -0,0 +1,147 @@
+/*
+ * Copyright 2012-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.autoconfigure.flyway;
+
+import java.lang.annotation.Annotation;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.function.Supplier;
+import java.util.stream.Stream;
+
+import javax.sql.DataSource;
+
+import org.flywaydb.core.Flyway;
+import org.flywaydb.core.api.callback.Callback;
+import org.flywaydb.core.api.migration.JavaMigration;
+
+import org.springframework.beans.factory.BeanFactory;
+import org.springframework.beans.factory.ListableBeanFactory;
+import org.springframework.beans.factory.ObjectProvider;
+import org.springframework.beans.factory.support.BeanDefinitionBuilder;
+import org.springframework.beans.factory.support.BeanDefinitionRegistry;
+import org.springframework.beans.factory.support.StaticListableBeanFactory;
+import org.springframework.boot.context.properties.bind.Bindable;
+import org.springframework.boot.context.properties.bind.Binder;
+import org.springframework.context.annotation.ImportBeanDefinitionRegistrar;
+import org.springframework.core.env.Environment;
+import org.springframework.core.type.AnnotationMetadata;
+import org.springframework.util.Assert;
+
+class FlywayInstancesRegistrar implements ImportBeanDefinitionRegistrar {
+	private final ListableBeanFactory listableBeanFactory;
+	private final Binder binder;
+
+	public FlywayInstancesRegistrar(BeanFactory beanFactory, Environment environment) {
+		this.listableBeanFactory = (ListableBeanFactory) beanFactory;
+		this.binder = Binder.get(environment);
+	}
+
+	@Override
+	public void registerBeanDefinitions(AnnotationMetadata importingClassMetadata, BeanDefinitionRegistry registry) {
+		FlywayInstancesProperties instancesProperties = new FlywayInstancesProperties();
+		this.binder.bind("spring.flyway", Bindable.ofInstance(instancesProperties));
+
+		if (instancesProperties.getInstances().isEmpty()) {
+			registry.registerBeanDefinition("flyway",
+					BeanDefinitionBuilder.genericBeanDefinition(Flyway.class, createFlywaySupplier(null, instancesProperties)).getBeanDefinition());
+
+			if (this.listableBeanFactory.getBeanNamesForType(FlywayMigrationInitializer.class).length == 0) {
+				registry.registerBeanDefinition("flywayMigrationInitializer",
+						BeanDefinitionBuilder.genericBeanDefinition(FlywayMigrationInitializer.class,
+								createFlywayMigrationInitializerSupplier(null, "flyway")).getBeanDefinition());
+			}
+		} else {
+			for (String flywayInstanceName : instancesProperties.getInstances().keySet()) {
+				FlywayProperties properties = bindFlywayInstanceProperties(flywayInstanceName);
+
+				if (properties.isEnabled()) {
+					String flywayBeanName = "flyway-" + flywayInstanceName;
+
+					registry.registerBeanDefinition(flywayBeanName,
+							BeanDefinitionBuilder.genericBeanDefinition(Flyway.class, createFlywaySupplier(flywayInstanceName, properties)).getBeanDefinition());
+
+					registry.registerBeanDefinition("flywayMigrationInitializer-" + flywayInstanceName,
+							BeanDefinitionBuilder.genericBeanDefinition(FlywayMigrationInitializer.class,
+									createFlywayMigrationInitializerSupplier(flywayInstanceName, flywayBeanName)).getBeanDefinition());
+				}
+			}
+		}
+	}
+
+	private FlywayProperties bindFlywayInstanceProperties(String flywayInstanceName) {
+		FlywayProperties properties = new FlywayProperties();
+		this.binder.bind("spring.flyway", Bindable.ofInstance(properties));
+		this.binder.bind("spring.flyway.instances." + flywayInstanceName, Bindable.ofInstance(properties));
+		return properties;
+	}
+
+	private Supplier<Flyway> createFlywaySupplier(String flywayInstanceName, FlywayProperties properties) {
+		return () -> {
+			ObjectProvider<FlywayConnectionDetails> connectionDetails = findBeans(flywayInstanceName, FlywayConnectionDetails.class, null, true, true);
+			ObjectProvider<DataSource> flywayDataSource = findBeans(flywayInstanceName, DataSource.class, FlywayDataSource.class, true, true);
+			ObjectProvider<FlywayConfigurationCustomizer> flywayConfigurationCustomizers = findBeans(flywayInstanceName, FlywayConfigurationCustomizer.class, null, false, true);
+			ObjectProvider<Callback> callbacks = findBeans(flywayInstanceName, Callback.class, null, false, true);
+			ObjectProvider<JavaMigration> javaMigrations = findBeans(flywayInstanceName, JavaMigration.class, null, true, false);
+
+			FlywayFactory flywayFactory = this.listableBeanFactory.getBean(FlywayFactory.class);
+			return flywayFactory.createFlyway(properties, connectionDetails, flywayDataSource, flywayConfigurationCustomizers, callbacks, javaMigrations);
+		};
+	}
+
+	private Supplier<FlywayMigrationInitializer> createFlywayMigrationInitializerSupplier(String flywayInstanceName, String flywayBeanName) {
+		return () -> {
+			ObjectProvider<FlywayMigrationStrategy> flywayMigrationStrategy = findBeans(flywayInstanceName, FlywayMigrationStrategy.class, null, true, true);
+			return new FlywayMigrationInitializer(this.listableBeanFactory.getBean(flywayBeanName, Flyway.class), flywayMigrationStrategy.getIfAvailable());
+		};
+	}
+
+	private <T> ObjectProvider<T> findBeans(String flywayInstanceName, Class<T> type, Class<? extends Annotation> additionalAnnotation, boolean preferInstanceBeans, boolean allowGeneralBeans) {
+		if (flywayInstanceName == null) {
+			return this.listableBeanFactory.getBeanProvider(type);
+		}
+
+		Map<String, T> generalBeans = new HashMap<>();
+		Map<String, T> instanceBeans = new HashMap<>();
+
+		for (Map.Entry<String, T> beanWithName : this.listableBeanFactory.getBeansOfType(type).entrySet()) {
+			if (additionalAnnotation != null && this.listableBeanFactory.findAnnotationOnBean(beanWithName.getKey(), additionalAnnotation) == null) {
+				continue;
+			}
+
+			FlywayInstance flywayInstanceSpecific = this.listableBeanFactory.findAnnotationOnBean(beanWithName.getKey(), FlywayInstance.class);
+			if (flywayInstanceSpecific == null) {
+				Assert.isTrue(allowGeneralBeans, "Undefined instance binding for bean " + beanWithName.getKey() + " of type " +  type.getName());
+
+				generalBeans.put(beanWithName.getKey(), beanWithName.getValue());
+			} else if (flywayInstanceSpecific.value().equals(flywayInstanceName)) {
+				instanceBeans.put(beanWithName.getKey(), beanWithName.getValue());
+			}
+		}
+
+		Stream<Map<String, T>> stream;
+		if (preferInstanceBeans && !instanceBeans.isEmpty()) {
+			stream = Stream.of(instanceBeans);
+		} else {
+			stream = Stream.of(generalBeans, instanceBeans);
+		}
+
+		StaticListableBeanFactory staticListableBeanFactory = new StaticListableBeanFactory();
+		stream.flatMap(map -> map.entrySet().stream()).forEach(beanWithName -> staticListableBeanFactory.addBean(beanWithName.getKey(), beanWithName.getValue()));
+		return staticListableBeanFactory.getBeanProvider(type);
+	}
+
+}

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/flyway/FlywayProperties.java

@@ -27,7 +27,6 @@
 import java.util.List;
 import java.util.Map;
 
-import org.springframework.boot.context.properties.ConfigurationProperties;
 import org.springframework.boot.context.properties.DeprecatedConfigurationProperty;
 import org.springframework.boot.convert.DurationUnit;
 
@@ -40,7 +39,6 @@
  * @author Chris Bono
  * @since 1.1.0
  */
-@ConfigurationProperties(prefix = "spring.flyway")
 public class FlywayProperties {
 
 	/**