Spring Zuul: Dynamically disable a route to a service

Question

I'm trying to disable a Zuul route to a microservice registered with Eureka at runtime (I'm using spring boot).

This is an example:

localhost/hello
localhost/world

Those two are the registered microservices. I would like to disable the route to one of them at runtime without shutting it down.

Is there a way to do this?

Thank you,

Nano

Answer 1

After a lot of efforts I came up with this solution. First, I used Netflix Archaius to watch a property file. Then I proceeded as follows:

public class ApplicationRouteLocator extends SimpleRouteLocator implements RefreshableRouteLocator {

public ApplicationRouteLocator(String servletPath, ZuulProperties properties) {
    super(servletPath, properties );
}


@Override
public void refresh() {
   doRefresh();
}
}

Made the doRefresh() method public by extending SimpleRouteLocator and calling its method in the overridden one of the interface RefreshableRouteLocator.

Then I redefined the bean RouteLocator with my custom implementation:

@Configuration
@EnableConfigurationProperties( { ZuulProperties.class } )
public class ZuulConfig {

public static ApplicationRouteLocator simpleRouteLocator;

@Autowired
private ZuulProperties zuulProperties;

@Autowired
private ServerProperties server;

@Bean
@Primary
public RouteLocator routeLocator() {
    logger.info( "zuulProperties are: {}", zuulProperties );
    simpleRouteLocator = new ApplicationRouteLocator( this.server.getServletPrefix(),
            this.zuulProperties );


    ConfigurationManager.getConfigInstance().addConfigurationListener( configurationListener );

    return simpleRouteLocator;
}


private ConfigurationListener configurationListener =
        new ConfigurationListener() {

            @Override
            public void configurationChanged( ConfigurationEvent ce ) {

                            // zuulProperties.getRoutes() do something
                            // zuulProperties.getIgnoredPatterns() do something
                            simpleRouteLocator.refresh();
                        }



                }

}

Every time a property in the file was modified an event was triggered and the ConfigurationEvent was able to deal with it (getPropertyName() and getPropertyValue() to extract data from the event). Since I also Autowired the ZuulProperties I was able to get access to it. With the right rule I could find whether the property of Zuul

zuul.ignoredPatterns

was modified changing its value in the ZuulProperties accordingly.