Adds setRequestHeader filter

fixes gh-138

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

@@ -53,6 +53,7 @@ import org.springframework.cloud.gateway.filter.factory.RewritePathGatewayFilter
 import org.springframework.cloud.gateway.filter.factory.SecureHeadersGatewayFilterFactory;
 import org.springframework.cloud.gateway.filter.factory.SecureHeadersProperties;
 import org.springframework.cloud.gateway.filter.factory.SetPathGatewayFilterFactory;
+import org.springframework.cloud.gateway.filter.factory.SetRequestHeaderGatewayFilterFactory;
 import org.springframework.cloud.gateway.filter.factory.SetResponseHeaderGatewayFilterFactory;
 import org.springframework.cloud.gateway.filter.factory.SetStatusGatewayFilterFactory;
 import org.springframework.cloud.gateway.filter.ratelimit.KeyResolver;
@@ -368,6 +369,11 @@ public class GatewayAutoConfiguration {
 		return new SecureHeadersGatewayFilterFactory(properties);
 	}
 
+	@Bean
+	public SetRequestHeaderGatewayFilterFactory setRequestHeaderGatewayFilterFactory() {
+		return new SetRequestHeaderGatewayFilterFactory();
+	}
+
 	@Bean
 	public SetResponseHeaderGatewayFilterFactory setResponseHeaderGatewayFilterFactory() {
 		return new SetResponseHeaderGatewayFilterFactory();

spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/filter/factory/SetRequestHeaderGatewayFilterFactory.java

@@ -0,0 +1,53 @@
+/*
+ * Copyright 2013-2017 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
+ *
+ *      http://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.factory;
+
+import java.util.Arrays;
+import java.util.List;
+
+import org.springframework.cloud.gateway.filter.GatewayFilter;
+import org.springframework.http.server.reactive.ServerHttpRequest;
+import org.springframework.tuple.Tuple;
+
+/**
+ * @author Spencer Gibb
+ */
+public class SetRequestHeaderGatewayFilterFactory implements GatewayFilterFactory {
+
+	@Override
+	public List<String> argNames() {
+		return Arrays.asList(NAME_KEY, VALUE_KEY);
+	}
+
+	@Override
+	public GatewayFilter apply(Tuple args) {
+		String name = args.getString(NAME_KEY);
+		String value = args.getString(VALUE_KEY);
+		return apply(name, value);
+	}
+
+	public GatewayFilter apply(String name, String value) {
+		return (exchange, chain) -> {
+			ServerHttpRequest request = exchange.getRequest().mutate()
+					.headers(httpHeaders -> httpHeaders.set(name, value))
+					.build();
+
+			return chain.filter(exchange.mutate().request(request).build());
+		};
+	}
+}

spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/route/builder/GatewayFilterSpec.java

@@ -38,6 +38,7 @@ import org.springframework.cloud.gateway.filter.factory.RequestRateLimiterGatewa
 import org.springframework.cloud.gateway.filter.factory.RewritePathGatewayFilterFactory;
 import org.springframework.cloud.gateway.filter.factory.SecureHeadersGatewayFilterFactory;
 import org.springframework.cloud.gateway.filter.factory.SetPathGatewayFilterFactory;
+import org.springframework.cloud.gateway.filter.factory.SetRequestHeaderGatewayFilterFactory;
 import org.springframework.cloud.gateway.filter.factory.SetResponseHeaderGatewayFilterFactory;
 import org.springframework.cloud.gateway.filter.factory.SetStatusGatewayFilterFactory;
 import org.springframework.cloud.gateway.filter.ratelimit.KeyResolver;
@@ -164,6 +165,10 @@ public class GatewayFilterSpec extends UriSpec {
 		return filter(getBean(SetPathGatewayFilterFactory.class).apply(template));
 	}
 
+	public GatewayFilterSpec setRequestHeader(String headerName, String headerValue) {
+		return filter(getBean(SetRequestHeaderGatewayFilterFactory.class).apply(headerName, headerValue));
+	}
+
 	public GatewayFilterSpec setResponseHeader(String headerName, String headerValue) {
 		return filter(getBean(SetResponseHeaderGatewayFilterFactory.class).apply(headerName, headerValue));
 	}

spring-cloud-gateway-core/src/test/java/org/springframework/cloud/gateway/filter/factory/SetRequestHeaderGatewayFilterFactoryTests.java

@@ -0,0 +1,83 @@
+/*
+ * Copyright 2013-2017 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
+ *
+ *      http://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.factory;
+
+import java.util.Map;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.boot.SpringBootConfiguration;
+import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.cloud.gateway.route.RouteLocator;
+import org.springframework.cloud.gateway.route.builder.RouteLocatorBuilder;
+import org.springframework.cloud.gateway.test.BaseWebClientTests;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Import;
+import org.springframework.test.annotation.DirtiesContext;
+import org.springframework.test.context.junit4.SpringRunner;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.springframework.boot.test.context.SpringBootTest.WebEnvironment.RANDOM_PORT;
+import static org.springframework.cloud.gateway.test.TestUtils.getMap;
+
+
+/**
+ * @author Spencer Gibb
+ * @author Biju Kunjummen
+ */
+@RunWith(SpringRunner.class)
+@SpringBootTest(webEnvironment = RANDOM_PORT)
+@DirtiesContext
+public class SetRequestHeaderGatewayFilterFactoryTests extends BaseWebClientTests {
+
+	@Test
+	public void setRequestHeaderFilterWorks() {
+		testClient.get().uri("/headers")
+				.header("Host", "www.setrequestheader.org")
+				.exchange()
+				.expectStatus().isOk()
+				.expectBody(Map.class)
+				.consumeWith(result -> {
+					Map<String, Object> headers = getMap(result.getResponseBody(), "headers");
+					assertThat(headers).containsEntry("X-Req-Foo", "Second");
+				});
+	}
+
+	@EnableAutoConfiguration
+	@SpringBootConfiguration
+	@Import(DefaultTestConfig.class)
+	public static class TestConfig {
+		@Value("${test.uri}")
+		String uri;
+
+		@Bean
+		public RouteLocator testRouteLocator(RouteLocatorBuilder builder) {
+			return builder.routes().route("test_set_request_header",
+                r -> r.order(-1)
+					.host("**.setrequestheader.org")
+					.prefixPath("/httpbin")
+					.addRequestHeader("X-Req-Foo", "First")
+					.setRequestHeader("X-Req-Foo", "Second")
+					.uri(uri))
+					.build();
+		}
+	}
+
+}