Quarkus - Using Flyway

Flyway is a popular database migration tool that is commonly used in JVM environments.

Quarkus provides first class support for using Flyway as will be explained in this guide.

Setting up support for Flyway

To start using Flyway with your project, you just need to:

  • add your migrations to the src/main/resources/db/migration folder as you usually do with Flyway

  • activate the migrate-at-start option to migrate the schema automatically or inject the Flyway object and run your migration as you normally do

In your pom.xml, add the following dependencies:

  • the Flyway extension

  • your JDBC driver extension (quarkus-jdbc-postgresql, quarkus-jdbc-h2, quarkus-jdbc-mariadb, …​)

<dependencies>
    <!-- Flyway specific dependencies -->
    <dependency>
        <groupId>io.quarkus</groupId>
        <artifactId>quarkus-flyway</artifactId>
    </dependency>

    <!-- JDBC driver dependencies -->
    <dependency>
        <groupId>io.quarkus</groupId>
        <artifactId>quarkus-jdbc-postgresql</artifactId>
    </dependency>
</dependencies>

Flyway support relies on the Quarkus datasource config. It can be customized for the default datasource as well as for every named datasource. First, you need to add the datasource config to the application.properties file in order to allow Flyway to manage the schema. Also, you can customize the Flyway behaviour by using the following properties:

The following is an example for the application.properties file:

# configure your datasource
quarkus.datasource.db-kind=postgresql
quarkus.datasource.username=sarah
quarkus.datasource.password=connor
quarkus.datasource.jdbc.url=jdbc:postgresql://localhost:5432/mydatabase

# Flyway minimal config properties
quarkus.flyway.migrate-at-start=true

# Flyway optional config properties
# quarkus.flyway.baseline-on-migrate=true
# quarkus.flyway.baseline-version=1.0.0
# quarkus.flyway.baseline-description=Initial version
# quarkus.flyway.connect-retries=10
# quarkus.flyway.schemas=TEST_SCHEMA
# quarkus.flyway.table=flyway_quarkus_history
# quarkus.flyway.locations=db/location1,db/location2
# quarkus.flyway.sql-migration-prefix=X
# quarkus.flyway.repeatable-sql-migration-prefix=K

Add a SQL migration to the default folder following the Flyway naming conventions: src/main/resources/db/migration/V1.0.0__Quarkus.sql

CREATE TABLE quarkus
(
  id   INT,
  name VARCHAR(20)
);
INSERT INTO quarkus(id, name)
VALUES (1, 'QUARKED');

Now you can start your application and Quarkus will run the Flyway’s migrate method according to your config:

@ApplicationScoped
public class MigrationService {
    // You can Inject the object if you want to use it manually
    @Inject
    Flyway flyway; (1)

    public void checkMigration() {
        // This will print 1.0.0
        System.out.println(flyway.info().current().getVersion().toString());
    }
}
1 Inject the Flyway object if you want to use it directly

Multiple datasources

Flyway can be configured for multiple datasources. The Flyway properties are prefixed exactly the same way as the named datasources, for example:

quarkus.datasource.db-kind=h2
quarkus.datasource.username=username-default
quarkus.datasource.jdbc.url=jdbc:h2:tcp://localhost/mem:default
quarkus.datasource.jdbc.min-size=3
quarkus.datasource.jdbc.max-size=13

quarkus.datasource.users.db-kind=h2
quarkus.datasource.users.username=username1
quarkus.datasource.users.jdbc.url=jdbc:h2:tcp://localhost/mem:users
quarkus.datasource.users.jdbc.min-size=1
quarkus.datasource.users.jdbc.max-size=11

quarkus.datasource.inventory.db-kind=h2
quarkus.datasource.inventory.username=username2
quarkus.datasource.inventory.jdbc.url=jdbc:h2:tcp://localhost/mem:inventory
quarkus.datasource.inventory.jdbc.min-size=2
quarkus.datasource.inventory.jdbc.max-size=12

# Flyway configuration for the default datasource
quarkus.flyway.schemas=DEFAULT_TEST_SCHEMA
quarkus.flyway.locations=db/default/location1,db/default/location2
quarkus.flyway.migrate-at-start=true

# Flyway configuration for the "users" datasource
quarkus.flyway.users.schemas=USERS_TEST_SCHEMA
quarkus.flyway.users.locations=db/users/location1,db/users/location2
quarkus.flyway.users.migrate-at-start=true

# Flyway configuration for the "inventory" datasource
quarkus.flyway.inventory.schemas=INVENTORY_TEST_SCHEMA
quarkus.flyway.inventory.locations=db/inventory/location1,db/inventory/location2
quarkus.flyway.inventory.migrate-at-start=true

Notice there’s an extra bit in the key. The syntax is as follows: quarkus.flyway.[optional name.][datasource property].

Without configuration, Flyway is set up for every datasource using the default settings.

Using the Flyway object

In case you are interested in using the Flyway object directly, you can inject it as follows:

If you enabled the quarkus.flyway.migrate-at-start property, by the time you use the Flyway instance, Quarkus will already have run the migrate operation
@ApplicationScoped
public class MigrationService {
    // You can Inject the object if you want to use it manually
    @Inject
    Flyway flyway; (1)

    @Inject
    @FlywayDataSource("inventory") (2)
    Flyway flywayForInventory;

    @Inject
    @Named("flyway_users") (3)
    Flyway flywayForUsers;

    public void checkMigration() {
        // Use the flyway instance manually
        flyway.clean(); (4)
        flyway.migrate();
        // This will print 1.0.0
        System.out.println(flyway.info().current().getVersion().toString());
    }
}
1 Inject the Flyway object if you want to use it directly
2 Inject Flyway for named datasources using the Quarkus FlywayDataSource qualifier
3 Inject Flyway for named datasources
4 Use the Flyway instance directly