Storing sessions in Redis with Spring Boot

Tomcat has nice support to use Redis for session replication with this awesome library. However Spring Boot launches embedded Tomcat, so there is no traditional XML configuration, it is still super easy to change default manager to use Redis for session replication, just define containerCustomizer bean, like:

@Configuration
@EnableAutoConfiguration
@ComponentScan
public class App {
  public App() {
  }

  @Bean
  public EmbeddedServletContainerCustomizer containerCustomizer(){
    return factory -> {
      TomcatEmbeddedServletContainerFactory containerFactory = (TomcatEmbeddedServletContainerFactory) factory;
      containerFactory.addContextValves(new RedisSessionHandlerValve());
      containerFactory.setTomcatContextCustomizers(Arrays.asList(context -> {
        context.setSessionTimeout(30);
        context.setManager(new RedisSessionManager(){{
          setHost("redis.server.com");
        }});
      }));
    };
  }

  public static void main(String[] args) throws Exception {
    SpringApplication.run(App.class, args);
  }
}

(this is syntax with new shiny Java 8 lambdas, but with few additional boring types it should compile in old Javas too).