How to register servlet on a different port in spring boot?

Question

In my casual spring boot application I regiser servlet like this.

    import io.prometheus.client.exporter.*
    .....
    @Bean
    public ServletRegistrationBean<MetricsServlet> registerMetricsServlet(MetricRegistry metricRegistry) {
        return new ServletRegistrationBean<>(new MetricsServlet(), "/metrics");
    }

This servlet is registred on the same port as application. The issue is that my infrastructure(k8s and etc) is expecting that application and metrics endpoint works on a different ports(like actuator does).

How can I register third party servlet on a ddifferent port ?

Answer 1

You can do it with multiple connectors and request filter. (All connectors are handle same way)

1. https://tech.asimio.net/2016/12/15/Configuring-Tomcat-to-Listen-on-Multiple-ports-using-Spring-Boot.html

pay attention to the lines from

   public FilterRegistrationBean javaMelodyRestrictingFilter(FilterRegistrationBean javaMelodyFilter) {...

2. spring boot 2.0 listening on multiple ports

Original answer here. Configure Spring Boot with two ports