flyway multitenant extension

bom/application/pom.xml

@@ -1060,6 +1060,16 @@
                 <artifactId>quarkus-flyway-deployment</artifactId>
                 <version>${project.version}</version>
             </dependency>
+            <dependency>
+                <groupId>io.quarkus</groupId>
+                <artifactId>quarkus-flyway-multitenant</artifactId>
+                <version>${project.version}</version>
+            </dependency>
+            <dependency>
+                <groupId>io.quarkus</groupId>
+                <artifactId>quarkus-flyway-multitenant-deployment</artifactId>
+                <version>${project.version}</version>
+            </dependency>
             <dependency>
                 <groupId>io.quarkus</groupId>
                 <artifactId>quarkus-flyway-postgresql</artifactId>

core/deployment/src/main/java/io/quarkus/deployment/Feature.java

@@ -25,6 +25,7 @@ public enum Feature {
     ELASTICSEARCH_REST_HIGH_LEVEL_CLIENT,
     ELASTICSEARCH_JAVA_CLIENT,
     FLYWAY,
+    FLYWAY_MULTITENANT,
     GRPC_CLIENT,
     GRPC_SERVER,
     HIBERNATE_ORM,

docs/src/main/asciidoc/flyway.adoc

@@ -315,7 +315,7 @@ NOTE: Without configuration, Flyway is set up for every datasource using the def
 
 == Customizing Flyway
 
-In cases where Flyway needs to be configured in addition to the configuration options that Quarkus provides, the `io.quarkus.flyway.FlywayConfigurationCustomizer` class comes in handy.
+In cases where Flyway needs to be configured in addition to the configuration options that Quarkus provides, the `io.quarkus.flyway.multitenant.FlywayConfigurationCustomizer` class comes in handy.
 
 To customize Flyway for the default datasource, simply add a bean like so:
 

extensions/flyway-multitenant/deployment/pom.xml

@@ -0,0 +1,97 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xmlns="http://maven.apache.org/POM/4.0.0"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <parent>
+        <artifactId>quarkus-flyway-multitenant-parent</artifactId>
+        <groupId>io.quarkus</groupId>
+        <version>999-SNAPSHOT</version>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+
+    <artifactId>quarkus-flyway-multitenant-deployment</artifactId>
+    <name>Quarkus - Flyway - Multitenant - Deployment</name>
+
+    <dependencies>
+        <dependency>
+            <groupId>io.quarkus</groupId>
+            <artifactId>quarkus-core-deployment</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>io.quarkus</groupId>
+            <artifactId>quarkus-arc-deployment</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>io.quarkus</groupId>
+            <artifactId>quarkus-flyway-deployment</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>io.quarkus</groupId>
+            <artifactId>quarkus-hibernate-orm-deployment</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>io.quarkus</groupId>
+            <artifactId>quarkus-flyway-multitenant</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>io.quarkus</groupId>
+            <artifactId>quarkus-vertx-http-dev-ui-tests</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>io.quarkus</groupId>
+            <artifactId>quarkus-junit5-internal</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>io.quarkus</groupId>
+            <artifactId>quarkus-test-h2</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>io.quarkus</groupId>
+            <artifactId>quarkus-jdbc-h2-deployment</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>io.quarkus</groupId>
+            <artifactId>quarkus-resteasy-jackson-deployment</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>io.rest-assured</groupId>
+            <artifactId>rest-assured</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <executions>
+                    <execution>
+                        <id>default-compile</id>
+                        <configuration>
+                            <annotationProcessorPaths>
+                                <path>
+                                    <groupId>io.quarkus</groupId>
+                                    <artifactId>quarkus-extension-processor</artifactId>
+                                    <version>${project.version}</version>
+                                </path>
+                            </annotationProcessorPaths>
+                            <compilerArgs>
+                                <arg>-AlegacyConfigRoot=true</arg>
+                            </compilerArgs>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
+        </plugins>
+    </build>
+</project>

extensions/flyway-multitenant/deployment/src/main/java/io/quarkus/flyway/multitenant/deployment/FlywayEnabled.java

@@ -0,0 +1,24 @@
+package io.quarkus.flyway.multitenant.deployment;
+
+import java.util.function.BooleanSupplier;
+
+import io.quarkus.flyway.multitenant.runtime.FlywayMultiTenantBuildTimeConfig;
+
+/**
+ * Supplier that can be used to only run build steps
+ * if the Flyway extension is enabled.
+ */
+public class FlywayEnabled implements BooleanSupplier {
+
+    private final FlywayMultiTenantBuildTimeConfig config;
+
+    FlywayEnabled(FlywayMultiTenantBuildTimeConfig config) {
+        this.config = config;
+    }
+
+    @Override
+    public boolean getAsBoolean() {
+        return config.enabled;
+    }
+
+}

extensions/flyway-multitenant/deployment/src/main/java/io/quarkus/flyway/multitenant/deployment/FlywayMultiTenantAlwaysEnabledProcessor.java

@@ -0,0 +1,14 @@
+package io.quarkus.flyway.multitenant.deployment;
+
+import io.quarkus.deployment.Feature;
+import io.quarkus.deployment.annotations.BuildProducer;
+import io.quarkus.deployment.annotations.BuildStep;
+import io.quarkus.deployment.builditem.FeatureBuildItem;
+
+public class FlywayMultiTenantAlwaysEnabledProcessor {
+
+    @BuildStep
+    void build(BuildProducer<FeatureBuildItem> featureProducer) {
+        featureProducer.produce(new FeatureBuildItem(Feature.FLYWAY_MULTITENANT));
+    }
+}

extensions/flyway-multitenant/deployment/src/main/java/io/quarkus/flyway/multitenant/deployment/FlywayMultiTenantCallbacksLocator.java

@@ -0,0 +1,105 @@
+package io.quarkus.flyway.multitenant.deployment;
+
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Modifier;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+import java.util.Optional;
+
+import org.flywaydb.core.api.callback.Callback;
+import org.jboss.jandex.ClassInfo;
+import org.jboss.jandex.DotName;
+
+import io.quarkus.deployment.annotations.BuildProducer;
+import io.quarkus.deployment.builditem.CombinedIndexBuildItem;
+import io.quarkus.deployment.builditem.nativeimage.ReflectiveClassBuildItem;
+import io.quarkus.flyway.multitenant.runtime.FlywayMultiTenantBuildTimeConfig;
+
+/**
+ * Logic to locate and process Flyway {@link Callback} classes.
+ * This class also helps to keep the {@link FlywayMultiTenantProcessor} class as lean as possible to make it easier to maintain
+ */
+class FlywayMultiTenantCallbacksLocator {
+    private final Collection<String> persistenceUnitNames;
+    private final FlywayMultiTenantBuildTimeConfig flywayBuildConfig;
+    private final CombinedIndexBuildItem combinedIndexBuildItem;
+    private final BuildProducer<ReflectiveClassBuildItem> reflectiveClassProducer;
+
+    private FlywayMultiTenantCallbacksLocator(Collection<String> persistenceUnitNames,
+            FlywayMultiTenantBuildTimeConfig flywayBuildConfig,
+            CombinedIndexBuildItem combinedIndexBuildItem, BuildProducer<ReflectiveClassBuildItem> reflectiveClassProducer) {
+        this.persistenceUnitNames = persistenceUnitNames;
+        this.flywayBuildConfig = flywayBuildConfig;
+        this.combinedIndexBuildItem = combinedIndexBuildItem;
+        this.reflectiveClassProducer = reflectiveClassProducer;
+    }
+
+    public static FlywayMultiTenantCallbacksLocator with(Collection<String> persistenceUnitNames,
+            FlywayMultiTenantBuildTimeConfig flywayBuildConfig,
+            CombinedIndexBuildItem combinedIndexBuildItem, BuildProducer<ReflectiveClassBuildItem> reflectiveClassProducer) {
+        return new FlywayMultiTenantCallbacksLocator(persistenceUnitNames, flywayBuildConfig, combinedIndexBuildItem,
+                reflectiveClassProducer);
+    }
+
+    /**
+     * Main logic to identify callbacks and return them to be processed by the {@link FlywayMultiTenantProcessor}
+     *
+     * @return Map containing the callbacks for each datasource. The datasource name is the map key
+     * @exception ClassNotFoundException if the {@link Callback} class cannot be located by the Quarkus class loader
+     * @exception InstantiationException if the {@link Callback} class represents an abstract class.
+     * @exception InvocationTargetException if the underlying constructor throws an exception.
+     * @exception IllegalAccessException if the {@link Callback} constructor is enforcing Java language access control
+     *            and the underlying constructor is inaccessible
+     */
+    public Map<String, Collection<Callback>> getCallbacks()
+            throws ClassNotFoundException, InvocationTargetException, InstantiationException, IllegalAccessException {
+        final Map<String, Collection<Callback>> callbacks = new HashMap<>();
+        for (String dataSourceName : persistenceUnitNames) {
+            final Collection<Callback> instances = callbacksForPersistenceUnit(dataSourceName);
+            callbacks.put(dataSourceName, instances);
+        }
+        return callbacks;
+    }
+
+    /**
+     *
+     * Reads the configuration, instantiates the {@link Callback} class. Also, adds it to the reflective producer
+     *
+     * @return List of callbacks for the datasource
+     * @exception ClassNotFoundException if the {@link Callback} class cannot be located by the Quarkus class loader
+     * @exception InstantiationException if the {@link Callback} class represents an abstract class.
+     * @exception InvocationTargetException if the underlying constructor throws an exception.
+     * @exception IllegalAccessException if the {@link Callback} constructor is enforcing Java language access control
+     *            and the underlying constructor is inaccessible
+     */
+    private Collection<Callback> callbacksForPersistenceUnit(String persistenceUnitName)
+            throws ClassNotFoundException, IllegalAccessException, InvocationTargetException, InstantiationException {
+        final Optional<List<String>> callbackConfig = flywayBuildConfig
+                .getConfigForPersistenceUnitName(persistenceUnitName).callbacks;
+        if (!callbackConfig.isPresent()) {
+            return Collections.emptyList();
+        }
+        final Collection<String> callbacks = callbackConfig.get();
+        final Collection<Callback> instances = new ArrayList<>(callbacks.size());
+        for (String callback : callbacks) {
+            final ClassInfo clazz = combinedIndexBuildItem.getIndex().getClassByName(DotName.createSimple(callback));
+            Objects.requireNonNull(clazz,
+                    "Flyway callback not found, please verify the fully qualified name for the class: " + callback);
+            if (Modifier.isAbstract(clazz.flags()) || !clazz.hasNoArgsConstructor()) {
+                throw new IllegalArgumentException(
+                        "Invalid Flyway callback. It shouldn't be abstract and must have a default constructor");
+            }
+            final Class<?> clazzType = Class.forName(callback, false, Thread.currentThread().getContextClassLoader());
+            final Callback instance = (Callback) clazzType.getConstructors()[0].newInstance();
+            instances.add(instance);
+            reflectiveClassProducer
+                    .produce(ReflectiveClassBuildItem.builder(clazz.name().toString()).build());
+        }
+        return instances;
+    }
+}