Spring API Gateway java.net.ConnectException: Connection timed out: no further information - spring-boot

Question

I have a spring boot app with simple GET method "sayHello" i have configured API gateway to route calls to my microservice module when uri pattern matches /ms1/**
Both gateway and microservice registered to the Registry service and dashboard displays both registered
API-GATEAY YAML configuration
server:
port: '8010'
spring:
application:
name: MY-GATEWAY
cloud:
compatibility-verifier:
enabled: false
gateway:
routes:
- id: MICRO-SERVICE1
uri: lb://MICRO-SERVICE1
predicates:
- Path=/ms1/**
eureka:
client:
register-with-eureka: true
fetch-registry: true
service-uri: http://localhost:8761/eureka/
intance:
hostname: localhost
MICRO-SERVICE1 YAML configuration
server:
port: '8030'
spring:
application:
name: MICRO-SERVICE1
eureka:
client:
register-with-eureka: true
fetch-registry: true
service-uri: http://localhost:8761/eureka/
intance:
hostname: localhost
Controller's GET method
#RestController
#RequestMapping("/ms1")
public class UATController {
#GetMapping(value = "/sayHello")
public #ResponseBody ResponseEntity<String> sayHello() {
String message = "Hello World";
return new ResponseEntity<String>(message, HttpStatus.OK);
}
}
I am getting following error when i access via gateway, however when i access my microservice directly it works any idea where i am wrong here?
http://localhost:8010/ms1/sayHello <- Not working via gateway
http://localhost:8030/ms1/sayHello <- Working direct access
Wed Dec 07 23:32:31 EST 2021
[83b324d4-2] There was an unexpected error (type=Internal Server Error, status=500).
Connection timed out: no further information: DESKTOP-1.verizon.net/192.168.1.160:8030
io.netty.channel.AbstractChannel$AnnotatedConnectException: Connection timed out: no further information: DESKTOP-1.verizon.net/192.168.1.160:8030
Suppressed: The stacktrace has been enhanced by Reactor, refer to additional information below:
Error has been observed at the following site(s):
*__checkpoint ⇢ org.springframework.cloud.gateway.filter.WeightCalculatorWebFilter [DefaultWebFilterChain]
*__checkpoint ⇢ org.springframework.boot.actuate.metrics.web.reactive.server.MetricsWebFilter [DefaultWebFilterChain]
*__checkpoint ⇢ HTTP GET "/ms1/sayHello" [ExceptionHandlingWebHandler]
Original Stack Trace:
Caused by: java.net.ConnectException: Connection timed out: no further information
at java.base/sun.nio.ch.Net.pollConnect(Native Method)
at java.base/sun.nio.ch.Net.pollConnectNow(Net.java:672)
at java.base/sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:946)
at io.netty.channel.socket.nio.NioSocketChannel.doFinishConnect(NioSocketChannel.java:330)
at io.netty.channel.nio.AbstractNioChannel$AbstractNioUnsafe.finishConnect(AbstractNioChannel.java:334)
at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:707)
at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:655)
at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:581)
at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:493)
at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:986)
at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
at java.base/java.lang.Thread.run(Thread.java:833)

Answer 1

I have faced the same issue today as well when running the micro services, the gateway and the Eureka discovery all on localhost.
I was able to solve it by adding eureka.instance.preferIpAddress=true to my application.properties of the micro services. That property causes that the services will advertise their IP addresses instead of the host names. More info here under point 2.6: https://cloud.spring.io/spring-cloud-netflix/multi/multi_spring-cloud-eureka-server.html. My guess is that there was an issue with forwarding the requests to the microservices due to using localhost.
Edit: Here are my settings
There is nothing special in my setup. These are the values I am using in my application.properties
The microservice is using:
spring.cloud.discovery.enabled=true
spring.application.name=[The name of my app]
eureka.client.register.with-eureka=true
eureka.client.service-url.defaultZone=http://localhost:8999/eureka
eureka.instance.prefer-ip-address=true
The properties for the gateway are similar to the service one.
The load balancing part looks like this:
spring.cloud.gateway.routes[0].id=[Same name as my app]
spring.cloud.gateway.routes[0].uri=lb://[name of my app]
spring.cloud.gateway.routes[0].predicates=Path=/test/**
Where test/** is the part of the Rest URL of my application

Answer 2

Adding DESKTOP-1.verizon.net to hosts file worked, following is entry I have added to C:\Windows\System32\drivers\etc\hosts file. Unfortunately eureka.instance.prefer-ip-address=true didn't work for me
127.0.0.1 DESKTOP-1.verizon.net

Answer 3

have added this settings in yml file in all services and its work for me.
eureka:
instance:
prefer-ip-address: true

Answer 4

I just faced the same issue, and in my case, I had a problem with port number. I was using the code below to set up the port for me:
server:
port: ${random.int(8010,8013)}
I noticed when the service starts, even though the log shows "Tomcat started on port(s): 8010", on Eureka's page shows "host.docker.internal:my-service:8011"
This error happens randomly, because sometimes when you re-start the microservice, it is able to register on Eureka correctly.
You can do a simple test using a non-random port number.
I haven't figured out how to solve it for random port number.
UPDATING:
I did this and worked fine for me:
server:
port: 0
spring:
application:
name: user-service
eureka:
instance:
hostname: localhost
prefer-ip-address: true
client:
serviceUrl:
defaultZone: http://localhost:9000/eureka/