Consider initialization of multiple datasources

[krabaey]

Sample project in attach with failing test cases, run via mvnw test

Two datasources are configured, each with a schema and data init file, however only the schema and data initialization from the primary datasource is executed.

I would have expected the data/schema init files both would be executed in their respective configured datasource.

Main reason seems to be that the spring DataSourceInitializerPostProcessor requests a DataSourceInitializerInvoker singleton which will then only execute intialization once.

A second issue seems to be that the DataSourceInitializerInvoker does not check the DataSourceSchemaCreatedEvent source to match the current datasource, so it might react to the wrong one.

Issue seems to be present from at least Spring Boot 2.0.0
demo.zip

[philwebb]

This is the expected behavior with the current implementation. The initializer currently only works with the @Primary datasource. The reason that foo-schema.sql is used is because you're also registering a DataSourceProperties bean as @Primary which will replace the usual spring.datasource properties.

So multiple datasource you'll currently need to use ResourceDatabasePopulator directly.

[philwebb]

See also #9528

[snicoll]

We have discussed the possibility to auto-configure multiple data sources and didn’t execute on it. For that reason, I think this issue should be closed.

[wilkinsona]

But with #9528 we may end up with an API that can be used to register a DataSource for initialisation. We'd then use that API for the auto-configured DataSource and make it available to users for use with their own, manually configured data sources. If anything, I could see this being or becoming a duplicate of #9528.

[philwebb]

See #15732

[philwebb]

Closing in favor of #9528