Unsupported Database: MariaDB 10.4

Which version and edition of Flyway are you using?

7.8.2 (latest)

Which client are you using? (Command-line, Java API, Maven plugin, Gradle plugin)

Java API

Which database are you using? (Type & version)

MariaDB 10.4

Which operating system are you using?

Debian 10

What did you do? (Please include the content causing the issue, any relevant configuration settings, the SQL statement(s) that failed (if any), and the command you ran)

var flyway = Flyway.configure(classLoader).dataSource(dataSource).load();
try {
    flyway.migrate();
} catch (final FlywayException e) {
    return Result.error(e);
}

What did you expect to see?

Successful migration

What did you see instead?

[21:01:49 INFO]: [org.flywaydb.core.internal.license.VersionPrinter] Flyway Community Edition 7.8.2 by Redgate
[21:01:49 INFO]: [com.zaxxer.hikari.HikariDataSource] SamplePool - Starting...
[21:01:49 INFO]: [com.zaxxer.hikari.HikariDataSource] SamplePool - Start completed.
[21:01:49 ERROR]: [ExamplePlugin] Jdbc url: jdbc:mariadb://127.0.0.1:3306/app?useUnicode=true&characterEncoding=utf-8&useSSL=false
[21:01:49 ERROR]: [ExamplePlugin] Migration error: 
org.flywaydb.core.api.FlywayException: Unsupported Database: MariaDB 10.4
                at org.flywaydb.core.internal.database.DatabaseTypeRegister.getDatabaseTypeForConnection(DatabaseTypeRegister.java:143) ~[?:?]
                at org.flywaydb.core.internal.jdbc.JdbcConnectionFactory.<init>(JdbcConnectionFactory.java:69) ~[?:?]
                at org.flywaydb.core.Flyway.execute(Flyway.java:505) ~[?:?]
                at org.flywaydb.core.Flyway.migrate(Flyway.java:165) ~[?:?]
                at ru.example.clans.service.simple.SqlMigrateService.migrate(SqlMigrateService.java:30) ~[?:?]
                at ru.example.clans.ExamplePlugin.onPluginEnable(ExamplePlugin.java:95) ~[?:?]
                at ru.coder.api.BenioPlugin.onEnable(BenioPlugin.java:51) ~[?:?]
                at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:263) ~[patched_1.16.5.jar:git-Paper-638]
                at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:380) ~[patched_1.16.5.jar:git-Paper-638]
                at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:483) ~[patched_1.16.5.jar:git-Paper-638]
                at org.bukkit.craftbukkit.v1_16_R3.CraftServer.enablePlugin(CraftServer.java:501) ~[patched_1.16.5.jar:git-Paper-638]
                at org.bukkit.craftbukkit.v1_16_R3.CraftServer.enablePlugins(CraftServer.java:415) ~[patched_1.16.5.jar:git-Paper-638]
                at net.minecraft.server.v1_16_R3.MinecraftServer.loadWorld(MinecraftServer.java:591) ~[patched_1.16.5.jar:git-Paper-638]
                at net.minecraft.server.v1_16_R3.DedicatedServer.init(DedicatedServer.java:281) ~[patched_1.16.5.jar:git-Paper-638]
                at net.minecraft.server.v1_16_R3.MinecraftServer.w(MinecraftServer.java:1065) ~[patched_1.16.5.jar:git-Paper-638]
                at net.minecraft.server.v1_16_R3.MinecraftServer.lambda$a$0(MinecraftServer.java:289) ~[patched_1.16.5.jar:git-Paper-638]
                at java.lang.Thread.run(Thread.java:832) [?:?]

[A248]

Test case with JUnit 5:

public class Flyway3168Test {

	private DataSource dataSource;

	@BeforeEach
	public void initDataSource() {
		HikariConfig hikariConfig = new HikariConfig();
		hikariConfig.setDriverClassName("org.hsqldb.jdbc.JDBCDriver");
		hikariConfig.setJdbcUrl("jdbc:hsqldb:mem:testdb");
		dataSource = new HikariDataSource(hikariConfig);
	}

	private void migrate() {
		Flyway.configure(getClass().getClassLoader())
				.locations("classpath:test-migrations") // Uses some migrations in src/test/resources/test-migrations
				.dataSource(dataSource)
				.load().migrate();
	}

	private void migrateUsing(ClassLoader contextClassLoader) {
		Thread currentThread = Thread.currentThread();
		ClassLoader originalLoader = currentThread.getContextClassLoader();
		currentThread.setContextClassLoader(contextClassLoader);
		try {
			migrate();
		} finally {
			currentThread.setContextClassLoader(originalLoader);
		}
	}

        // PASSES always
	@Test
	public void flywayVisibleFromContextLoader() {
		migrateUsing(getClass().getClassLoader());
	}

        // PASSES on 7.7.1, FAILS on 7.8.2
	@Test
	public void flywayNotVisibleFromContextLoader() {
		ClassLoader emptyLoader = new ClassLoader(null) {};
		migrateUsing(emptyLoader);
	}

	@AfterEach
	public void resetFlywayState() throws NoSuchFieldException, IllegalAccessException {
                // No other good way to do this
		Field field = DatabaseTypeRegister.class.getDeclaredField("hasRegisteredDatabaseTypes");
		field.setAccessible(true);
		field.set(null, false);
	}

}

[A248]

I ran into this same problem. Unit tests pass but migration fails in the deployment environment. It occurs when Flyway and the user code is in a child ClassLoader, which is unreachable from the context ClassLoader.

On previous versions, in my case 7.7.1, using Flyway.configure(classLoader) works fine and allows Flyway to detect migrations reachable in the specified ClassLoader which are not available in the context ClassLoader.

The issue is that the ServiceLoader.load(Class) uses the context ClassLoader:

https://github.com/flyway/flyway/blob/7f9921a58eb3b35a217e47e3dd1bf9a787386175/flyway-core/src/main/java/org/flywaydb/core/internal/database/DatabaseTypeRegister.java#L54

To solve this, ServiceLoader.load(Class, ClassLoader) can be used instead. It probably should be used instead, considering the context loader is more of a mechanism to workaround inflexible existing APIs (from what I understand).