AddRequestHeader Filter

The AddRequestHeader is a "before" filter that takes a name and value parameter. The following example configures an AddRequestHeader filter:

application.yml
spring:
  cloud:
    gateway:
      mvc:
        routes:
        - id: add_request_header_route
          uri: https://example.org
          filters:
          - AddRequestHeader=X-Request-red, blue
GatewaySampleApplication.java
import static org.springframework.cloud.gateway.server.mvc.filter.BeforeFilterFunctions.addRequestHeader;
import static org.springframework.cloud.gateway.server.mvc.handler.GatewayRouterFunctions.route;
import static org.springframework.cloud.gateway.server.mvc.handler.HandlerFunctions.http;

@Configuration
class RouteConfiguration {

    @Bean
    public RouterFunction<ServerResponse> gatewayRouterFunctionsAddReqHeader() {
        return route(GET("/red"), http("https://example.org"))
                .before(addRequestHeader("X-Request-red", "blue"));
    }
}

This listing adds X-Request-red:blue header to the downstream request’s headers for all matching requests.

AddRequestHeader is aware of the URI variables used to match a path or host. URI variables may be used in the value and are expanded at runtime. The following example configures an AddRequestHeader filter that uses a variable:

GatewaySampleApplication.java
@Configuration
class RouteConfiguration {

    @Bean
    public RouterFunction<ServerResponse> gatewayRouterFunctionsAddReqHeader() {
        return route(GET("/red/{segment}"), http("https://example.org"))
                .before(addRequestHeader("X-Request-red", "blue-{segment}"));
    }
}