[FIXED] Issue with CORS configuration on Spring Cloud Gateway

Issue

I am trying to build Gateway proxy using Spring Cloud Gateway.

I am able to route my requests to respective services using RouteLocator in Spring Cloud. But I am not able to configure CORS for the paths which are routing through RouteLocator.

I tried all the possibilities which are mentioned in the Spring Cloud document.

I am facing following error in my webpage:

My code looks like Application.java

@SpringBootApplication
public class Application {

public static void main(String[] args) {
    SpringApplication.run(Application.class, args);
}

// tag::route-locator[]
@Bean
public RouteLocator myRoutes(RouteLocatorBuilder builder) {
    return builder.routes()
            .route(p -> p
                    .path("/order/**")
                    .filters(f -> f.setResponseHeader("Access-Control-Allow-Origin", "http://localhost:8081")
                    )
                    .uri("http://localhost:9090"))
            .route(p -> p
                    .path("/priority-model/selection/**")
                    .filters(f -> f.addResponseHeader("Access-Control-Allow-Origin", "http://localhost:8081")
                    )
                    .uri("http://localhost:9090"))
            .build();
}

}

application.yml

server:
  port: 8080

spring:
  cloud:
    gateway:
      globalcors:
        corsConfigurations:
          '[/**]':
            allowedOrigins: "*"
            allowedMethods:
              - GET

buils.gradle

    buildscript {
    repositories {
        mavenCentral()
    }
    dependencies {
        classpath("org.springframework.boot:spring-boot-gradle-plugin:2.0.5.RELEASE")
    }
}

apply plugin: 'java'
apply plugin: 'eclipse'
apply plugin: 'idea'
apply plugin: 'org.springframework.boot'
apply plugin: 'io.spring.dependency-management'

bootJar {
    baseName = 'gs-gateway'
    version =  '0.1.0'
}

repositories {
    mavenCentral()
}

sourceCompatibility = 1.8
targetCompatibility = 1.8

dependencyManagement {
    imports {
        mavenBom "org.springframework.cloud:spring-cloud-dependencies:Finchley.SR2"
    }
}

dependencies {
    compile("org.springframework.cloud:spring-cloud-starter-gateway")
    compile("org.springframework.cloud:spring-cloud-starter-netflix-hystrix")
    compile("org.springframework.cloud:spring-cloud-starter-contract-stub-runner"){
        exclude group: "org.springframework.boot", module: "spring-boot-starter-web"
    }
    compile group: 'org.springframework.cloud', name: 'spring-cloud-gateway-webflux', version: '2.0.2.RELEASE'
    testCompile("org.springframework.boot:spring-boot-starter-test")
}

Solution

By default, API Gateway enables CORS for all the origins, if you want to allow only whitelisted origins then use globalcors configurations.
spring: cloud: gateway: globalcors: corsConfigurations: '[/**]': allowedOrigins: "*" allowedMethods: - GET

Answered By - samba