'Unknown Error' when sending a POST request to my Spring Boot API Gateway from my Angular app and CORS is configured correctly

Question

I'm "Getting 'Http failure response for http://localhost:8080/api/user/auth/login: 0 Unknown Error' when sending a POST request to my Spring Boot API Gateway from my Angular app. CORS is configured correctly, and the same request works fine when sent directly to the user-service. The API Gateway logs don't show any errors, and the browser console doesn't provide additional insights. Any suggestions on how to troubleshoot this issue?".

API Gateway application.properties

eureka.client.register-with-eureka=true
eureka.client.fetch-registry=true
spring.application.name=api-gateway
eureka.client.service-url.defaultZone= http://localhost:8761/eureka
server.port=8080
## LOGS
logging.level.root=INFO
#class responsible for defining and identifying routes
logging.level.org.springframework.cloud.gateway.route.RouteDefinitionLocator = INFO
logging.level.org.springframework.cloud.gateway = TRACE
## END LOGS

## Routes
spring.cloud.gateway.routes[0].id=user-service
spring.cloud.gateway.routes[0].uri = lb://user-service
spring.cloud.gateway.routes[0].predicates[0]=Path=/api/user/**

Console error:

API GatewayCors config

import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.CorsRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

@Configuration
public class CorsConfig implements WebMvcConfigurer {
    @Override
    public void addCorsMappings(CorsRegistry registry) {
        registry.addMapping("/**")
                .allowedOrigins("*") // Replace with your Angular application's URL
                .allowedMethods("GET", "POST", "PUT", "DELETE")
                .allowedHeaders("Content-Type", "Authorization");
    }
}

PS: When I change the URL in my angular app to directly send a request to the user-service everything works fine.

Answer 1

please create an application.yml file in your api-gateway and place the following configuration inside.

spring:
  application:
    name: gateway

  cloud:
    gateway:
      global-cors:
        corsConfigurations:
          '[/**]':
            allowedOrigins: "*"
            allowedMethods:
              - GET
              - POST
              - PUT
              - DELETE
              - PATCH
            allowedHeaders:
              - "Origin"
              - "Content-Type"
              - "Accept"
              - "Authorization"
              - "User-Key"
              - "Request-Tracker"
              - "Session-Tracker"
              - "X-XSRF-TOKEN"
              - "X-IBM-CLIENT-ID"
              - "Message-ID"
              - "X-IBM-CLIENT-SECRET"
      default-filters:
        - DedupeResponseHeader=Access-Control-Allow-Credentials Access-Control-Allow-Origin, RETAIN_FIRST