Removes predicate path exchange attr for forwards.

This moves the removal of GATEWAY_PREDICATE_PATH_CONTAINER_ATTR to ServerWebExchangeUtils.handle() which is now used in SpringCloudCircuitBreakerFilterFactory and ForwardRoutingFilter.

Fixes gh-2950

spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/filter/ForwardRoutingFilter.java

@@ -28,6 +28,7 @@ import org.springframework.web.reactive.DispatcherHandler;
 import org.springframework.web.server.ServerWebExchange;
 
 import static org.springframework.cloud.gateway.support.ServerWebExchangeUtils.GATEWAY_REQUEST_URL_ATTR;
+import static org.springframework.cloud.gateway.support.ServerWebExchangeUtils.handle;
 import static org.springframework.cloud.gateway.support.ServerWebExchangeUtils.isAlreadyRouted;
 
 public class ForwardRoutingFilter implements GlobalFilter, Ordered {
@@ -71,7 +72,7 @@ public class ForwardRoutingFilter implements GlobalFilter, Ordered {
 			log.trace("Forwarding to URI: " + requestUrl);
 		}
 
-		return this.getDispatcherHandler().handle(exchange);
+		return handle(this.getDispatcherHandler(), exchange);
 	}
 
 }

spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/filter/factory/SpringCloudCircuitBreakerFilterFactory.java

@@ -43,9 +43,9 @@ import static java.util.Collections.singletonList;
 import static java.util.Optional.ofNullable;
 import static org.springframework.cloud.gateway.support.GatewayToStringStyler.filterToStringCreator;
 import static org.springframework.cloud.gateway.support.ServerWebExchangeUtils.CIRCUITBREAKER_EXECUTION_EXCEPTION_ATTR;
-import static org.springframework.cloud.gateway.support.ServerWebExchangeUtils.GATEWAY_PREDICATE_PATH_CONTAINER_ATTR;
 import static org.springframework.cloud.gateway.support.ServerWebExchangeUtils.GATEWAY_REQUEST_URL_ATTR;
 import static org.springframework.cloud.gateway.support.ServerWebExchangeUtils.containsEncodedParts;
+import static org.springframework.cloud.gateway.support.ServerWebExchangeUtils.handle;
 import static org.springframework.cloud.gateway.support.ServerWebExchangeUtils.reset;
 
 /**
@@ -107,7 +107,6 @@ public abstract class SpringCloudCircuitBreakerFilterFactory
 					}
 
 					exchange.getResponse().setStatusCode(null);
-					reset(exchange);
 
 					// TODO: copied from RouteToRequestUrlFilter
 					URI uri = exchange.getRequest().getURI();
@@ -116,14 +115,13 @@ public abstract class SpringCloudCircuitBreakerFilterFactory
 					URI requestUrl = UriComponentsBuilder.fromUri(uri).host(null).port(null)
 							.uri(config.getFallbackUri()).scheme(null).build(encoded).toUri();
 					exchange.getAttributes().put(GATEWAY_REQUEST_URL_ATTR, requestUrl);
-					exchange.getAttributes().remove(GATEWAY_PREDICATE_PATH_CONTAINER_ATTR);
 					addExceptionDetails(t, exchange);
 
 					// Reset the exchange
 					reset(exchange);
 
 					ServerHttpRequest request = exchange.getRequest().mutate().uri(requestUrl).build();
-					return getDispatcherHandler().handle(exchange.mutate().request(request).build());
+					return handle(getDispatcherHandler(), exchange.mutate().request(request).build());
 				}).onErrorResume(t -> handleErrorWithoutFallback(t, config.isResumeWithoutError()));
 			}
 

spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/support/ServerWebExchangeUtils.java

@@ -46,6 +46,7 @@ import org.springframework.http.server.reactive.ServerHttpRequest;
 import org.springframework.http.server.reactive.ServerHttpRequestDecorator;
 import org.springframework.http.server.reactive.ServerHttpResponse;
 import org.springframework.util.Assert;
+import org.springframework.web.reactive.DispatcherHandler;
 import org.springframework.web.server.ServerWebExchange;
 import org.springframework.web.util.UriComponentsBuilder;
 
@@ -401,4 +402,18 @@ public final class ServerWebExchangeUtils {
 		return decorator;
 	}
 
+	/**
+	 * One place to handle forwarding using DispatcherHandler. Allows for common code to
+	 * be reused.
+	 * @param handler The DispatcherHandler.
+	 * @param exchange The ServerWebExchange.
+	 * @return value from handler.
+	 */
+	public static Mono<Void> handle(DispatcherHandler handler, ServerWebExchange exchange) {
+		// remove attributes that may disrupt the forwarded request
+		exchange.getAttributes().remove(GATEWAY_PREDICATE_PATH_CONTAINER_ATTR);
+
+		return handler.handle(exchange);
+	}
+
 }

spring-cloud-gateway-server/src/test/java/org/springframework/cloud/gateway/filter/ForwardRoutingFilterStaticIntegrationTests.java

@@ -0,0 +1,50 @@
+/*
+ * Copyright 2013-2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.cloud.gateway.filter;
+
+import org.junit.jupiter.api.Test;
+
+import org.springframework.boot.SpringBootConfiguration;
+import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.cloud.gateway.test.BaseWebClientTests;
+import org.springframework.context.annotation.Import;
+import org.springframework.test.context.ActiveProfiles;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.springframework.boot.test.context.SpringBootTest.WebEnvironment.RANDOM_PORT;
+
+@SpringBootTest(webEnvironment = RANDOM_PORT)
+@ActiveProfiles("forwardstatic")
+public class ForwardRoutingFilterStaticIntegrationTests extends BaseWebClientTests {
+
+	@Test
+	public void gatewayRequestsMeterFilterHasTags() {
+		testClient.get().uri("/mydocs").exchange().expectStatus().isOk().expectBody(String.class)
+				.consumeWith(result -> {
+					assertThat(result.getResponseBody()).contains("Docs 123");
+				});
+	}
+
+	@EnableAutoConfiguration
+	@SpringBootConfiguration
+	@Import(DefaultTestConfig.class)
+	public static class CustomConfig {
+
+	}
+
+}

spring-cloud-gateway-server/src/test/resources/application-forwardstatic.yml

@@ -0,0 +1,8 @@
+spring:
+  cloud:
+    gateway:
+      routes:
+      - uri: forward:/docs.html
+        id: static_docs_route
+        predicates:
+        - Path=/mydocs

spring-cloud-gateway-server/src/test/resources/static/httpbin/docs.html

@@ -0,0 +1,21 @@
+<!--
+  ~ Copyright 2013-2023 the original author or authors.
+  ~
+  ~ Licensed under the Apache License, Version 2.0 (the "License");
+  ~ you may not use this file except in compliance with the License.
+  ~ You may obtain a copy of the License at
+  ~
+  ~      https://www.apache.org/licenses/LICENSE-2.0
+  ~
+  ~ Unless required by applicable law or agreed to in writing, software
+  ~ distributed under the License is distributed on an "AS IS" BASIS,
+  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  ~ See the License for the specific language governing permissions and
+  ~ limitations under the License.
+  -->
+
+<html>
+<body>
+<h1>Docs 123</h1>
+</body>
+</html>