Flyway configuration ignores init-sqls when using spring.datasource.* properties

[ThomasKasene]

I'm trying to set the spring.flyway.init-sqls property to run a little statement before Flyway does anything with the migration scripts, while re-using the spring.datasource.* properties for the Flyway connection. That doesn't seem to be straight-forward, however.

I have the following in my application.yml:

spring:
  datasource:
    url: <url>
    username: <username>
    password: <password>
  flyway.init-sqls: SET ROLE '<username>'

Now, in FlywayAutoConfiguration.FlywayConfiguration there's a method that looks like this:

private DataSource configureDataSource(FluentConfiguration configuration, FlywayProperties properties,
        DataSourceProperties dataSourceProperties, DataSource flywayDataSource, DataSource dataSource) {
    if (properties.isCreateDataSource()) {
        String url = getProperty(properties::getUrl, dataSourceProperties::determineUrl);
        String user = getProperty(properties::getUser, dataSourceProperties::determineUsername);
        String password = getProperty(properties::getPassword, dataSourceProperties::determinePassword);
        configuration.dataSource(url, user, password);
        if (!CollectionUtils.isEmpty(properties.getInitSqls())) {
            String initSql = StringUtils.collectionToDelimitedString(properties.getInitSqls(), "\n");
            configuration.initSql(initSql);
        }
    }
    else if (flywayDataSource != null) {
        configuration.dataSource(flywayDataSource);
    }
    else {
        configuration.dataSource(dataSource);
    }
    return configuration.getDataSource();
}

This is the only place where I can find any usage of spring.flyway.init-sqls, but I'm noticing that properties.isCreateDataSource() only returns true if spring.flyway.url or spring.flyway.user are defined. Therefore, the code that uses init-sqls is never reached.

Is this expected behavior? I would have expected that as long as spring.datasource.url or spring.datasource.username is set, it's not necessary to also define spring.flyway.url or spring.flyway.user. It appears to work when I do this:

spring:
  datasource:
    url: <url>
    username: <username>
    password: <password>
  flyway:
    init-sqls: SET ROLE '<username>'
    url: ${spring.datasource.url}

I have a workaround for my case, but I'd like to hear if there's something I'm missing?

[wilkinsona]

Thanks for the report. When Spring Boot's initSql support was added (in Spring Boot 1.1) we were using Flyway 3.0 where it was only possible to specify SQL to initialise a connection when configuring Flyway's data source using a url, username, and password, rather than a DataSource instance. This changed in Flyway 5.2 but we missed it.

I see no reason not to apply spring.flyway.init-sqls irrespective of how the DataSource is being configured. I think we should have done that when we upgraded to 5.2.