Add support for auto-configuring an indexed reactive session repository

[TMRGZ]

As noted in the Spring Session configuration documentation, reactive indexed repositories can only be enabled through annotations, which limits the configuration flexibility via application.properties.

• https://docs.spring.io/spring-session/reference/configuration/redis.html

• https://docs.spring.io/spring-session/reference/configuration/reactive-redis-indexed.html

Additionally, the auto-configuration classes do not account for important properties such as configureRedisAction and namespace.

• https://github.com/spring-projects/spring-boot/blob/main/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/session/RedisSessionConfiguration.java

• https://github.com/spring-projects/spring-boot/blob/main/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/session/RedisReactiveSessionConfiguration.java

Simply adding the equivalent methods resolves this issue, as shown in the following configuration:

@Configuration(proxyBeanMethods = false)
@ConditionalOnProperty(prefix = "spring.session.redis", name = "repository-type", havingValue = "indexed")
@Import(RedisIndexedWebSessionConfiguration.class)
@EnableConfigurationProperties(RedisSessionProperties.class)
static class IndexedRedisSessionConfiguration {

  @Bean
  @ConditionalOnMissingBean
  ConfigureReactiveRedisAction configureRedisAction(RedisSessionProperties redisSessionProperties) {
    return switch (redisSessionProperties.getConfigureAction()) {
      case NOTIFY_KEYSPACE_EVENTS -> new ConfigureNotifyKeyspaceEventsReactiveAction();
      case NONE -> ConfigureReactiveRedisAction.NO_OP;
    };
  }

  @Bean
  @Order(Ordered.HIGHEST_PRECEDENCE)
  ReactiveSessionRepositoryCustomizer<ReactiveRedisIndexedSessionRepository> springBootSessionRepositoryCustomizer(
      SessionProperties sessionProperties, RedisSessionProperties redisSessionProperties,
      ServerProperties serverProperties) {
    return (sessionRepository) -> {
      PropertyMapper map = PropertyMapper.get().alwaysApplyingWhenNonNull();
      map.from(sessionProperties.determineTimeout(() -> serverProperties.getReactive().getSession().getTimeout()))
          .to(sessionRepository::setDefaultMaxInactiveInterval);
      map.from(redisSessionProperties::getNamespace).to(sessionRepository::setRedisKeyNamespace);
      map.from(redisSessionProperties::getSaveMode).to(sessionRepository::setSaveMode);
    };
  }

}

Additionally, it would be helpful to add a similar check for non-indexed repositories when the cleanup-cron property is enabled.

I can provide a PR if needed

[wilkinsona]

Thanks for the report.

The missing support for spring.session.redis.configure-action looks like an oversight. Support was added to Spring Session in 3.3 to which we upgraded in Spring Boot 3.3. We'll have to discuss this as a team to see if we want to treat adding support as enhancement or as a bug of omission.

As far as I can tell, spring.session.redis.namespace is already supported when using a reactive session repository:

spring-boot/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/session/RedisReactiveSessionConfiguration.java

Line 57 in 8704448

map.from(redisSessionProperties::getNamespace).to(sessionRepository::setRedisKeyNamespace);

This functionality was added when we started supporting reactive in Spring Boot 2.0.

Can you please clarify what you believe to be missing from the reactive session support beyond spring.session.redis.configure-action?

[TMRGZ]

That config works when the default reactive redis session repository is used, but since to use the indexed one you have to use the @EnableRedisIndexedWebSession annotation it's ignored and uses the configurations provided in the annotation.

I'll clarify that this affects only the reactive indexed repository

[wilkinsona]

I've opened #42834 to look at improving the properties so that it's clearer which properties apply in which situations.