Mongock migrations

Helpers for running Mongock migrations using the same MongoClient as the rest of the application, so migrations share transactional state with the surrounding code.

fun Mongo.runMigrations(packageName: String, vararg dependencies: Any)
fun Mongo.runMigration(migrationClass: KClass<*>, vararg dependencies: Any)

Example

mongo.runMigrations(
    packageName = "myapp.persistence.migrations",
    productService,
    auditService
)

dependencies are registered with the Mongock runner and can be injected into migration classes.

Migration interfaces

Three convenience interfaces for the most common migration shapes. Implementations are picked up by package or class scan.

ModelMigration

For schema-style changes that cannot run inside a transaction (e.g. index creation). The @BeforeExecution hook is wired by these interfaces so you only implement model(...) and rollbackModel(...).

class CreateProductIndexes : ModelMigration {
    override fun model(mongo: Mongo) {
        mongo.database.getCollection<Product>("products").createIndices(
            Product::name.asc(),
            *TimestampedDocument.allIndices()
        )
    }
}

DataMigration

For data changes that run inside a transaction.

class FixProductPrices : DataMigration {
    override fun data(mongo: Mongo, javaSession: JavaClientSession) {
        // operate via javaSession.kotlin() to use the Kotlin driver
    }
    override fun rollbackData(mongo: Mongo, javaSession: JavaClientSession) { /* ... */ }
}

ModelAndDataMigration

Combines both phases for migrations that need to alter the schema and then move data accordingly.