Register this EmbeddedServletContainerCustomizer @bean in a Spring Boot application to customize the embedded Tomcat instance. In particular, this sets up SSL support for the container. I quite like this because it uses Java 8 lambas to nice effect. No finals, no anonymous inner classes. it just... works.

gistfile1.java

  @Bean 
  EmbeddedServletContainerCustomizer containerCustomizer(
        @Value("${keystore.file}") Resource keystoreFile,
        @Value("${keystore.pass}") String keystorePass) throws Exception {

      String absoluteKeystoreFile = keystoreFile.getFile().getAbsolutePath();
      
      return (ConfigurableEmbeddedServletContainer container) -> {

          if (container instanceof TomcatEmbeddedServletContainerFactory) {

              TomcatEmbeddedServletContainerFactory tomcat = (TomcatEmbeddedServletContainerFactory) container;
              tomcat.addConnectorCustomizers(
                      (connector) -> {
                          connector.setPort(8443);
                          connector.setSecure(true);
                          connector.setScheme("https");
                          Http11NioProtocol proto = (Http11NioProtocol) connector.getProtocolHandler();
                          proto.setSSLEnabled(true);
                          proto.setKeystoreFile(absoluteKeystoreFile);
                          proto.setKeystorePass(keystorePass);
                          proto.setKeystoreType("PKCS12");
                          proto.setKeyAlias("tomcat");
                      }
              );
          }
      };
  }

A single Bean... without a class. I keep struggling - the example is incomplete. Where this bean must be declared? In Application with main class? - Throws Caused by: java.lang.IllegalArgumentException: A ServletContext is required to configure default servlet handling.

How does this befriend @EnableAutoConfiguration?

What is the wrapper class? If I put it to separate configuration class then my changes are not picked up - ignored. Neither setPort works neither cookie max age.

Tried component wrapper, no way, the customizations are ignored. The entity is scanned..