https://spring.io/guides/gs/spring-cloud-loadbalancer/
https://docs.spring.io/spring-cloud-commons/docs/current/reference/html/#spring-cloud-loadbalancer
https://docs.spring.io/spring-cloud-commons/docs/current/reference/html/#instance-health-check-for-loadbalancer

samples
import org.springframework.cloud.client.loadbalancer.LoadBalanced;

@Configuration
public class RestTemplateConfiguration {
    ...
    @Bean
    @LoadBalanced
    public RestTemplate restTemplate() {
        return new RestTemplate();
    }
    ...
}

application.yml

spring:
  cloud:
    loadbalancer:
      zone: "zone" #remove it, after https://github.com/spring-cloud/spring-cloud-netflix/commit/64e283201198da8cc05eadc9a640384fbec3c9ba is released
    kubernetes:
      enabled: false
      discovery:
        metadata:
          addAnnotations: true
          addLabels: false

eureka:
  client:
    enabled: false

security:
  oauth2:
    resource:
      token-info-uri: http://auth-server/oauth/check_token


---
spring:
  profiles: simple-discovery
  cloud:
    discovery:
      client:
        simple:
          instances:
            cmp-dev:
              - uri: http://localhost:8180

resttemplate:
  loadbalancer:
    enabled: true

---
spring:
  profiles: eureka
eureka:
  client:
    enabled: true
    serviceUrl:
      defaultZone: http://localhost:8761/eureka/
  instance:
    hostname: ${spring.cloud.client.hostname}
    instance-id: ${spring.cloud.client.hostname}:${spring.application.name}:${server.port}
    metadata-map:
      instanceId: ${eureka.instance.instance-id}

---
spring:
  profiles: kubernetes
  cloud:
    kubernetes:
      enabled: true


application-test.yml

spring:
  cloud:
    discovery:
      client:
        simple:
          instances:
            test-auth-server:
              - uri: http://localhost:12345
            test-designer:
              - uri: http://localhost:12345
security:
  oauth2:
    client:
      client-id: ingestion-gateway
      client-secret: testsecret
    resource:
      token-info-uri: http://test-auth-server/oauth/check_token