API Gateway는 사용자의 설정에 따라서 client 대신 요청하고 client의 요청에 응답하는 프록시 구조이다.
API Gateway는 단일 진입점이다. 클라이언트는 API Gateway만 접근할 수 있다.
https://spring.io/blog/2018/12/12/spring-cloud-greenwich-rc1-available-now
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 FilterConfig {
@Bean
public RouteLocator gatewayRoutes(RouteLocatorBuilder builder) {
return builder.routes()
.route(r -> r.path("/first-service/**")
.filters(f -> f.addRequestHeader("first-request", "first-request-header")
.addResponseHeader("first-response", "first-response-header"))
.uri("http://localhost:8081"))
.route(r -> r.path("/second-service/**")
.filters(f -> f.addRequestHeader("second-request", "second-request-header")
.addResponseHeader("second-response", "second-response-header"))
.uri("http://localhost:8082"))
.build();
}
}
import lombok.extern.slf4j.Slf4j;
import org.springframework.cloud.gateway.filter.GatewayFilter;
import org.springframework.cloud.gateway.filter.factory.AbstractGatewayFilterFactory;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.stereotype.Component;
import reactor.core.publisher.Mono;
@Component
@Slf4j
public class CustomFilter extends AbstractGatewayFilterFactory<CustomFilter.Config> {
public CustomFilter() {
super(Config.class);
}
@Override
public GatewayFilter apply(Config config) {
// Custom Pre Filter
return (exchange, chain) -> {
ServerHttpRequest request = exchange.getRequest();
ServerHttpResponse response = exchange.getResponse();
log.info("Custom PRE filter: request id -> {}", request.getId());
// Custom Post Filter
return chain.filter(exchange).then(Mono.fromRunnable(() -> {
log.info("Custom POST filter: response code -> {}", response.getStatusCode());
}));
};
}
public static class Config {
// Put the configuration properties
}
}
spring:
application:
name: apigateway-service
cloud:
gateway:
routes:
- id: first-service
uri: http://localhost:8081/
predicates:
- Path=/first-service/**
filters:
- CustomFilter