Integrate Mongeez with Spring Boot and Spring Data MongoDB - spring-boot

Question

I want to integrate Mongeez with my Spring Boot application and was wondering how to properly run Mongeez during application startup. Mongeez suggests creating a MongeezRunner bean. However, the challenge is to run Mongeez before any of the Spring Data initialization is happening, specifically, before the MongoTemplate instance is created. This is crucial because there might be changes in the database that prevent the application to start at all (e.g. changing index definitions).
My current approach is to provide the MongoTemplate bean myself, running Mongeez before creating it:
#Bean
public MongoTemplate mongoTemplate(Mongo mongo, MongoDbFactory mongoDbFactory,
MongoConverter converter) throws IOException {
// make sure that Mongeez runs before Spring Data is initialized
runMongeez(mongo);
return new MongoTemplate(mongoDbFactory, converter);
}
private void runMongeez(Mongo mongo) throws IOException {
Mongeez mongeez = new Mongeez();
mongeez.setMongo(mongo);
mongeez.setDbName(mongodbDatabaseName);
mongeez.setFile(new ClassPathResource("/db/migrations.xml"));
mongeez.process();
}
It works, but it feels like a hack. Is there any other way to do this?

Answer 1

After taking a look at Spring Boot's source code, it turns out that this problem isn't anything new. The FlywayAutoConfiguration for example has to make sure that Flyway (a migration tool for SQL-based databases) runs before any EntityManagerFactory beans are created. To achieve this the auto-configuration registers a BeanFactoryPostProcessor that dynamically makes every EntityManagerFactory bean depend on the Flyway bean, thus forcing Spring to create the Flyway bean first.
I solved my problem by creating a Spring Boot starter with a similar auto-configuration for Mongeez: mongeez-spring-boot-starter.