One of the important functions of gateway is routing and forwarding. We often encounter the problem of forwarding failure
for example, the front-end configuration is as follows:

 // api interface request address
 window.SITE_CONFIG['baseUrl'] = 'http://localhost:90/api';

The application.yml configuration of gateway is as follows:

server:
  port: 90
spring:
  application:
    name: threat-gateway
  cloud:
    gateway:
      routes:
#        threat-ip microservice routing and forwarding
        - id: ip_route
# The forwarding address of the matching route
          uri: lb://threat-ip
          predicates:
            - Path=/api/cyber_threat_ip/**
          filters:
            - RewritePath=/api/(?<segment>.*),/$\{segment}

The reason for the error may be that the registry (such as Nacos) is not enabled, resulting in the unrecognized name of the microservice
it is revised as follows:

#          Match the forwarding address of the route (8082 is the threat-ip microservice port)
          uri: localhost:8082

As a result, an error was reported because http://, should be added in front of the URI, as follows:

#          Match the forwarding address of the route (8082 is the threat-ip microservice port)
          uri: http://localhost:8082

As a result, you can visit it

of course, the rewritepath path rewriting error in filters may also cause access error. Other reasons will be added later.