How to set up liquibase in Spring for multiple data sources?

Question

I need to set up liquibase for two datasources in Spring, at the moment it seems that only one liquibase set up is possib

Answer 1

I was in the need of supporting a dynamic amount of DataSources, not a fixed number of them. I found that you can use the same SpringLiquibase bean for multiple DataSources by making a service like this:

@Service
@DependsOn("liquibase")
public class LiquibaseService {

    @Autowired
    @Qualifier("liquibase")
    private SpringLiquibase liquibase;

    @PostConstruct
    public void initialize() {

        /* Obtain datasources from wherever. I obtain them from a master DB. It's up to you. */
        List dataSources = obtainDataSources();

        for (DataSource dataSource : dataSources) {
            try {
                liquibase.setDataSource(dataSource);
                liquibase.setChangeLog("classpath:liquibase/emp.changelog.xml");
                liquibase.setShouldRun(true);

                // This runs Liquibase
                liquibase.afterPropertiesSet();

            } catch (LiquibaseException ex) {
                throw new RuntimeException(ex);
            }
        }
    }

}

For this to work, you should have a SpringLiquibase bean declared somewhere. In this example, I got this in one of my configuration files:

@Bean
public SpringLiquibase liquibase(LiquibaseProperties properties) {

    SpringLiquibase liquibase = new SpringLiquibase();
    liquibase.setDataSource(systemDataSource);
    liquibase.setChangeLog("classpath:liquibase/sis.changelog.xml");
    liquibase.setContexts(properties.getContexts());
    liquibase.setDefaultSchema(properties.getDefaultSchema());
    liquibase.setDropFirst(properties.isDropFirst());


    liquibase.setLabels(properties.getLabels());
    liquibase.setChangeLogParameters(properties.getParameters());
    liquibase.setRollbackFile(properties.getRollbackFile());

    // This is because we are running the process manually. Don't let SpringLiquibase do it.
    liquibase.setShouldRun(false);

    return liquibase;
}

The above highly depends on your DataSource configuration requirements. You could also need to put this on your main Application class so the Spring-Liquibase auto-configuration doesn't kick in:

@SpringBootApplication(exclude = {
    LiquibaseAutoConfiguration.class
})
public class Application {

    // Stuff...

}