CODEWITHSUNDEEP
spring-bootmicroservicesspring-cloud-gateway
Factor Three
Factor Three

Reputation: 2274

Spring Cloud Gateway not forwarding correctly

I have a Spring Boot application that is attempting to use Spring Cloud Gateway to access some microservices. The code I am using is based on instructions read at:

https://betterjavacode.com/programming/how-to-use-api-gateway-with-spring-cloud

Basically, my application duplicates the code provided on that site, including the two test microservices that the author created:

@RestController
@RequestMapping("/vendor")
public class VendorController
{
    @GetMapping("/total")
    public List vendors()
    {
        List list = new ArrayList<>();
        list.add("CJI Consultants");
        list.add("Signature Consultants");
        list.add("Deloitte");
        return list;
    }
}

and

@RestController
@RequestMapping("/customer")
public class CustomerController
{
    @GetMapping("/total")
    public List customers()
    {
        List list = new ArrayList<>();
        list.add("Microsoft");
        list.add("Amazon");
        list.add("Apple");
        return list;
    }
}

My actual gateway code is similar to the author's:

package com.betterjavacode.apigatewaydemo.config;

import org.springframework.cloud.gateway.route.RouteLocator;
import org.springframework.cloud.gateway.route.builder.RouteLocatorBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class SpringCloudConfig
{
    @Bean
    public RouteLocator gatewayRoutes(RouteLocatorBuilder routeLocatorBuilder)
    {
        return routeLocatorBuilder.routes()
                .route("customerModule", rt -> rt.path("/customer/**")
                        .uri("http://localhost:8081/"))
                .route("vendorModule", rt -> rt.path("/vendor/**")
                    .uri("http://localhost:8082/"))
                    .build();

    }
}

Unfortunately, when I run this application, enter the correct URLs:

http://localhost:8080/vendor/total

and

http://localhost:8080/customer/total

I get 404 errors!

The only way I seem able to access the two microservices through the gateway is to change the path to "/**". For example, in order to access the customer microservice I have to change:

.route("customerModule", rt -> rt.path("/customer/**") .uri("http://localhost:8081/"))

to

v.route("customerModule", rt -> rt.path("/**") .uri("http://localhost:8081/"))

then I can see the customer microservice output without problems. Of course, I cannot use the same path for both routes. It looks like this gateway is only able to handle one route using the "/**" path.

Am I missing something here? Can someone give some idea of why this isn't working properly? How can I get this gateway to forward to the paths it should be going to?

Upvotes: 1

Views: 5763

Answers (2)

Factor Three
Factor Three

Reputation: 2274

I believe I have resolved the problem. It turns out that, for reasons unknown, whenever a route other than "/**" is used in the Gateway, the URI must not contain the HTTP prefix.

In other words, instead of having a route:

route("customerModule", rt -> rt.path("/customer/**")
                    .uri("http://localhost:8081/"))

The route should be without the HTTP prefix:

.route("customerModule", rt -> rt.path("/customer/**")
                    .uri("localhost:8081/"))

I do not know why this works, but it does. I can access the microservices as long as I format the uri without the prefix.

I discovered this by accident. I would be curious to know why it works that way, but at least this requirement should be documented.

Upvotes: 4

cherful
cherful

Reputation: 189

you can try to use StripPrefix parameter.

return routeLocatorBuilder.routes()
                .route("customerModule", rt -> rt.path("/customer/**")
                        .filters(f -> f.stripPrefix(0))
                        .uri("http://localhost:8081/"))
                .route("vendorModule", rt -> rt.path("/vendor/**")
                    .filters(f -> f.stripPrefix(0))
                    .uri("http://localhost:8082/"))
                    .build();

or you can remove the @RequestMapping("/customer") and @RequestMapping("/vendor") because it deletes the prefix path before sending it downstream.

Upvotes: 0

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