Add a property to disable the gateway.

spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/config/GatewayAutoConfiguration.java

@@ -27,6 +27,7 @@ import org.springframework.boot.autoconfigure.AutoConfigureBefore;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.boot.autoconfigure.web.reactive.HttpHandlerAutoConfiguration;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.cloud.gateway.actuate.GatewayEndpoint;
@@ -103,6 +104,7 @@ import rx.RxReactiveStreams;
  * @author Spencer Gibb
  */
 @Configuration
+@ConditionalOnProperty(name = "spring.cloud.gateway.enabled", matchIfMissing = true)
 @EnableConfigurationProperties
 @AutoConfigureBefore(HttpHandlerAutoConfiguration.class)
 @AutoConfigureAfter(GatewayLoadBalancerClientAutoConfiguration.class)