Spring Cloud Kubernetes, Gateway Route Mapping

I am learning Spring boot kubernetes and trying to setup spring cloud gateway for my services. I believe with Spring cloud gateway we don;t have to use ribbon for load balancing any more. So If I don;t use ribbon then the configuration for routes changes as well. I looked over the sites for suggestion and following is what I found :-

routes:
- id: department_route
  uri: http://departmentservice:4200 # 
  predicates:
  - Path=/* 

In this case the uri has a hardcoded value of port at which the service is available. Is this is recommended approach ?

And then there is another flavor of the configuration which looks like this and Not sure what url-expression trying to do :-

spring:
  application.name: gateway
  cloud:
    gateway:
      discovery:
        locator:
          enabled: true
          url-expression: "'http://'+serviceId"
  server.port: 8080

Is it not possible to do a service discovery by name and append the predicate after that?

I am Still working on fixing the Spring Cloud Gateway project of main but following has worked for me. I have configured the routes via Zuul so make sure your dependencies and configuration related to it matches :-

<dependencies>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-netflix-zuul</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-kubernetes-all</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-sleuth</artifactId>
    </dependency>

**Config :: application.yaml ::**

    zuul:
      routes:
        shopping-cart-service:
          path: "/shopping-cart-service/**"
        item-service:
          path: "/item-service/**"