Ensure data.sql / schema.sql support is disabled automatically when using Flyway/Liquibase

[philwebb]

See #20920 for background.

[ThomasVitale]

If this issue is open to community contribution, I'm available to work on it.

[wilkinsona]

@ThomasVitale Thanks very much for the offer. That'd be great, yes please. Let us know if you have any questions.

[ThomasVitale]

@wilkinsona thank you and sorry for the late answer. I looked into the code and it seems that the DataSourceInitializer class is the one responsible for handling the schema.sql and data.sql files. Right now, there's a condition about whether to run the scripts that is based on the value of spring.datasource.initialization-mode and the data source type (embedded or not). So, if I use H2 and Flyway (and I don't explicitly set the initialization mode to false), then the scripts are run.

spring-boot/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/jdbc/DataSourceInitializer.java

Line 123 in 558c2b4

private boolean isEnabled() {

I thought about two possible solutions that I'd like to validate with you.
A) Extending the condition in DataSourceInitializer to include a check for Flyway/Liquibase.
B) Preventing the loading of DataSourceInitializationConfiguration if either Flyway or Liquibase is present, so that we don't register the DataSourceInitializerPostProcessor bean at all.

[wilkinsona]

@ThomasVitale Thanks for taking a look.

I think, ideally, DataSourceInitializationConfiguration would back off when Flyway or Liquibase is going to run. Unfortunately, after a brief look at the code, I'm not sure of the best way to make that happen. The auto-configuration for Flyway and Liquibase runs after the DataSource auto-configuration so we can't simply look for a Flyway or Liquibase bean in the context when deciding whether or not to auto-configure data source initialization.

[ThomasVitale]

Good point! Both FlywayAutoConfiguration and LiquibaseAutoConfiguration are loaded after DataSourceAutoConfiguration, so we can't check the beans for building the conditional. What about the properties? The autoconfiguration for Flyway and Liquibase is only loaded if spring.flyway.enabled=true and spring.liquibase.enabled=true, respectively. What if we checked for the presence of Flyway/Liquibase in the classpath and whether the corresponding property is true? Though, it would probably not be the cleanest solution.

[wilkinsona]

What if we checked for the presence of Flyway/Liquibase in the classpath and whether the corresponding property is true? Though, it would probably not be the cleanest solution.

I agree that may not be the cleanest. I think we'd be in danger of duplicating the Flyway and Liquibase auto-configuration conditions in the DataSource initialization auto-configuration.

The core team discussed this one yesterday and decided that it's something that should be tackled as part of a broader revamp of DataSource initialization that we'd like to do in 3.0. Thanks anyway for taking a look.