Allow Servlet Filters to be applied to Actuator endpoints when using a separate management port

I noticed that some of my custom filters are not applied to Actuator endpoints when a different management port is defined.

Even using :

@ManagementContextConfiguration
public class MicroServiceManagementAutoConfiguration {

  @Bean
  public FilterRegistrationBean<TestFilter> testFilter() {
    final FilterRegistrationBean<TestFilter> registrationBean  = new FilterRegistrationBean<>();

    registrationBean.setFilter(new TestFilter());
    registrationBean.addUrlPatterns("/*");

    return registrationBean;
  }
}

// registered in META-INF/spring.factories#org.springframework.boot.actuate.autoconfigure.ManagementContextConfiguration

The TestFilter is successfully applied when management.server.port == server.port but never applied when management.server.port != server.port.

Start by reproducing the behavior with a separate management.server.port and inspect the ManagementContextConfiguration and FilterRegistrationBean registration described in the issue, including META-INF/spring.factories. Trace how the management context creates its servlet filters, then verify that TestFilter is applied to Actuator endpoints on both shared and separate ports.