Configuration for Spring Cloud Gateway is driven by a collection of `RouteDefinitionLocator`s.
RouteDefinitionLocator.java.
public interface RouteDefinitionLocator { Flux<RouteDefinition> getRouteDefinitions(); }
By default, a PropertiesRouteDefinitionLocator loads properties using Spring Boot’s @ConfigurationProperties mechanism.
The configuration examples above all use a shortcut notation that uses positional arguments rather than named ones. The two examples below are equivalent:
application.yml.
spring: cloud: gateway: routes: # ===================================== - id: setstatus_route uri: https://example.org filters: - name: SetStatus args: status: 401 - id: setstatusshortcut_route uri: https://example.org filters: - SetStatus=401
For some usages of the gateway, properties will be adequate, but some production use cases will benefit from loading configuration from an external source, such as a database. Future milestone versions will have RouteDefinitionLocator implementations based off of Spring Data Repositories such as: Redis, MongoDB and Cassandra.
To allow for simple configuration in Java, there is a fluent API defined in the Routes class.
GatewaySampleApplication.java.
// static imports from GatewayFilters and RoutePredicates @Bean public RouteLocator customRouteLocator(ThrottleGatewayFilterFactory throttle) { return Routes.locator() .route("test") .predicate(host("**.abc.org").and(path("/image/png"))) .addResponseHeader("X-TestHeader", "foobar") .uri("http://httpbin.org:80") .route("test2") .predicate(path("/image/webp")) .add(addResponseHeader("X-AnotherHeader", "baz")) .uri("http://httpbin.org:80") .route("test3") .order(-1) .predicate(host("**.throttle.org").and(path("/get"))) .add(throttle.apply(tuple().of("capacity", 1, "refillTokens", 1, "refillPeriod", 10, "refillUnit", "SECONDS"))) .uri("http://httpbin.org:80") .build(); }
This style also allows for more custom predicate assertions. The predicates defined by RouteDefinitionLocator beans are combined using logical and. By using the fluent Java API, you can use the and(), or() and negate() operators on the Predicate class.