Parse predicate if needed. Allow extra args in predicate. Create Header Predicate

src/main/java/org/springframework/cloud/gateway/config/GatewayAutoConfiguration.java

@@ -8,6 +8,7 @@ import org.springframework.cloud.gateway.actuate.GatewayEndpoint;
 import org.springframework.cloud.gateway.filter.GatewayFilter;
 import org.springframework.cloud.gateway.filter.RouteToRequestUrlFilter;
 import org.springframework.cloud.gateway.handler.GatewayFilteringWebHandler;
+import org.springframework.cloud.gateway.handler.predicate.HeaderPredicateFactory;
 import org.springframework.cloud.gateway.handler.predicate.HostPredicateFactory;
 import org.springframework.cloud.gateway.handler.predicate.GatewayPredicateFactory;
 import org.springframework.cloud.gateway.handler.GatewayWebHandler;
@@ -76,6 +77,11 @@ public class GatewayAutoConfiguration {
 		return new MethodPredicateFactory();
 	}
 
+	@Bean
+	public HeaderPredicateFactory headerPredicateFactory() {
+		return new HeaderPredicateFactory();
+	}
+
 	@Configuration
 	@ConditionalOnClass(Endpoint.class)
 	protected static class GatewayActuatorConfiguration {

src/main/java/org/springframework/cloud/gateway/config/GatewayProperties.java

@@ -1,11 +1,8 @@
 package org.springframework.cloud.gateway.config;
 
-import java.net.URI;
 import java.util.ArrayList;
 import java.util.List;
-import java.util.Objects;
 
-import org.hibernate.validator.constraints.NotEmpty;
 import org.springframework.boot.context.properties.ConfigurationProperties;
 
 import javax.validation.Valid;
@@ -32,108 +29,4 @@ public class GatewayProperties {
 		this.routes = routes;
 	}
 
-	public static class Route {
-		@NotEmpty
-		private String id;
-
-		@NotEmpty
-		@Valid
-		private List<Predicate> predicates = new ArrayList<>();
-
-		@NotNull
-		private URI downstreamUrl;
-
-		public String getId() {
-			return id;
-		}
-
-		public void setId(String id) {
-			this.id = id;
-		}
-
-		public List<Predicate> getPredicates() {
-			return predicates;
-		}
-
-		public void setPredicates(List<Predicate> predicates) {
-			this.predicates = predicates;
-		}
-
-		public URI getDownstreamUrl() {
-			return downstreamUrl;
-		}
-
-		public void setDownstreamUrl(URI downstreamUrl) {
-			this.downstreamUrl = downstreamUrl;
-		}
-
-		@Override
-		public boolean equals(Object o) {
-			if (this == o) return true;
-			if (o == null || getClass() != o.getClass()) return false;
-			Route route = (Route) o;
-			return Objects.equals(id, route.id) &&
-					Objects.equals(predicates, route.predicates) &&
-					Objects.equals(downstreamUrl, route.downstreamUrl);
-		}
-
-		@Override
-		public int hashCode() {
-			return Objects.hash(id, predicates, downstreamUrl);
-		}
-
-		@Override
-		public String toString() {
-			return "Route{" +
-					"id='" + id + '\'' +
-					", predicates=" + predicates +
-					", downstreamUrl=" + downstreamUrl +
-					'}';
-		}
-	}
-
-	public static class Predicate {
-		@NotNull
-		private String name;
-		@NotNull
-		private String value;
-
-		public String getName() {
-			return name;
-		}
-
-		public void setName(String name) {
-			this.name = name;
-		}
-
-		public String getValue() {
-			return value;
-		}
-
-		public void setValue(String value) {
-			this.value = value;
-		}
-
-		@Override
-		public boolean equals(Object o) {
-			if (this == o) return true;
-			if (o == null || getClass() != o.getClass()) return false;
-			Predicate predicate = (Predicate) o;
-			return Objects.equals(name, predicate.name) &&
-					Objects.equals(value, predicate.value);
-		}
-
-		@Override
-		public int hashCode() {
-			return Objects.hash(name, value);
-		}
-
-		@Override
-		public String toString() {
-			return "Predicate{" +
-					"name='" + name + '\'' +
-					", value='" + value + '\'' +
-					'}';
-		}
-	}
 }

src/main/java/org/springframework/cloud/gateway/config/PredicateDefinition.java

@@ -0,0 +1,90 @@
+package org.springframework.cloud.gateway.config;
+
+import java.util.Arrays;
+import java.util.Objects;
+
+import javax.validation.ValidationException;
+import javax.validation.constraints.NotNull;
+
+import static org.springframework.util.StringUtils.tokenizeToStringArray;
+
+/**
+ * @author Spencer Gibb
+ */
+public class PredicateDefinition {
+	@NotNull
+	private String name;
+	@NotNull
+	private String value;
+
+	private String[] args;
+
+	public PredicateDefinition() {
+	}
+
+	public PredicateDefinition(String text) {
+		String[] parts = text.split("=");
+		if (parts.length != 2) {
+			throw new ValidationException("Unable to parse Predicate text '" + text + "'" +
+					", must be of the form name=value");
+		}
+		setName(parts[0]);
+
+		String[] args = tokenizeToStringArray(parts[1], ",");
+
+		setValue(args[0]);
+
+		if (args.length > 1) {
+			setArgs(Arrays.copyOfRange(args, 1, args.length));
+		}
+	}
+
+	public String getName() {
+		return name;
+	}
+
+	public void setName(String name) {
+		this.name = name;
+	}
+
+	public String getValue() {
+		return value;
+	}
+
+	public void setValue(String value) {
+		this.value = value;
+	}
+
+	public String[] getArgs() {
+		return args;
+	}
+
+	public void setArgs(String[] args) {
+		this.args = args;
+	}
+
+	@Override
+	public boolean equals(Object o) {
+		if (this == o) return true;
+		if (o == null || getClass() != o.getClass()) return false;
+		PredicateDefinition that = (PredicateDefinition) o;
+		return Objects.equals(name, that.name) &&
+				Objects.equals(value, that.value) &&
+				Arrays.equals(args, that.args);
+	}
+
+	@Override
+	public int hashCode() {
+		return Objects.hash(name, value, args);
+	}
+
+	@Override
+	public String toString() {
+		final StringBuilder sb = new StringBuilder("PredicateDefinition{");
+		sb.append("name='").append(name).append('\'');
+		sb.append(", value='").append(value).append('\'');
+		sb.append(", args=").append(Arrays.toString(args));
+		sb.append('}');
+		return sb.toString();
+	}
+}

src/main/java/org/springframework/cloud/gateway/config/Route.java

@@ -0,0 +1,73 @@
+package org.springframework.cloud.gateway.config;
+
+import org.hibernate.validator.constraints.NotEmpty;
+
+import javax.validation.Valid;
+import javax.validation.constraints.NotNull;
+import java.net.URI;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Objects;
+
+/**
+ * @author Spencer Gibb
+ */
+public class Route {
+	@NotEmpty
+	private String id;
+
+	@NotEmpty
+	@Valid
+	private List<PredicateDefinition> predicates = new ArrayList<>();
+
+	@NotNull
+	private URI downstreamUrl;
+
+	public String getId() {
+		return id;
+	}
+
+	public void setId(String id) {
+		this.id = id;
+	}
+
+	public List<PredicateDefinition> getPredicates() {
+		return predicates;
+	}
+
+	public void setPredicates(List<PredicateDefinition> predicates) {
+		this.predicates = predicates;
+	}
+
+	public URI getDownstreamUrl() {
+		return downstreamUrl;
+	}
+
+	public void setDownstreamUrl(URI downstreamUrl) {
+		this.downstreamUrl = downstreamUrl;
+	}
+
+	@Override
+	public boolean equals(Object o) {
+		if (this == o) return true;
+		if (o == null || getClass() != o.getClass()) return false;
+		Route route = (Route) o;
+		return Objects.equals(id, route.id) &&
+				Objects.equals(predicates, route.predicates) &&
+				Objects.equals(downstreamUrl, route.downstreamUrl);
+	}
+
+	@Override
+	public int hashCode() {
+		return Objects.hash(id, predicates, downstreamUrl);
+	}
+
+	@Override
+	public String toString() {
+		return "Route{" +
+				"id='" + id + '\'' +
+				", predicates=" + predicates +
+				", downstreamUrl=" + downstreamUrl +
+				'}';
+	}
+}

src/main/java/org/springframework/cloud/gateway/filter/RouteToRequestUrlFilter.java

@@ -5,7 +5,7 @@ import java.net.URI;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.springframework.cloud.gateway.config.GatewayProperties;
-import org.springframework.cloud.gateway.config.GatewayProperties.Route;
+import org.springframework.cloud.gateway.config.Route;
 import org.springframework.core.Ordered;
 import org.springframework.web.server.ServerWebExchange;
 import org.springframework.web.server.WebFilterChain;

src/main/java/org/springframework/cloud/gateway/handler/ServerWebExchangePredicateHandlerMapping.java

@@ -7,7 +7,8 @@ import java.util.function.Predicate;
 
 import org.springframework.beans.BeansException;
 import org.springframework.cloud.gateway.config.GatewayProperties;
-import org.springframework.cloud.gateway.config.GatewayProperties.Route;
+import org.springframework.cloud.gateway.config.Route;
+import org.springframework.cloud.gateway.config.PredicateDefinition;
 import org.springframework.cloud.gateway.handler.predicate.GatewayPredicateFactory;
 import org.springframework.web.reactive.handler.AbstractHandlerMapping;
 import org.springframework.web.server.ServerWebExchange;
@@ -113,10 +114,10 @@ public class ServerWebExchangePredicateHandlerMapping extends AbstractHandlerMap
 
 
 	private Predicate<ServerWebExchange> combinePredicates(Route route) {
-		List<GatewayProperties.Predicate> predicates = route.getPredicates();
+		List<PredicateDefinition> predicates = route.getPredicates();
 		Predicate<ServerWebExchange> predicate = lookup(predicates.get(0));
 
-		for (GatewayProperties.Predicate andPredicate : predicates.subList(1, predicates.size())) {
+		for (PredicateDefinition andPredicate : predicates.subList(1, predicates.size())) {
 			Predicate<ServerWebExchange> found = lookup(andPredicate);
 			predicate = predicate.and(found);
 		}
@@ -124,12 +125,12 @@ public class ServerWebExchangePredicateHandlerMapping extends AbstractHandlerMap
 		return predicate;
 	}
 
-	private Predicate<ServerWebExchange> lookup(GatewayProperties.Predicate predicate) {
+	private Predicate<ServerWebExchange> lookup(PredicateDefinition predicate) {
 		GatewayPredicateFactory found = this.predicateFactories.get(predicate.getName());
 		if (found == null) {
 			throw new IllegalArgumentException("Unable to find GatewayPredicateFactory with name " + predicate.getName());
 		}
-		return found.create(predicate.getValue());
+		return found.create(predicate.getValue(), predicate.getArgs());
 	}
 
 	/**

src/main/java/org/springframework/cloud/gateway/handler/predicate/GatewayPredicateFactory.java

@@ -1,9 +1,9 @@
 package org.springframework.cloud.gateway.handler.predicate;
 
-import org.springframework.web.server.ServerWebExchange;
-
 import java.util.function.Predicate;
 
+import org.springframework.web.server.ServerWebExchange;
+
 /**
  * @author Spencer Gibb
  */
@@ -11,5 +11,5 @@ public interface GatewayPredicateFactory {
 
 	String getName();
 
-	Predicate<ServerWebExchange> create(String value);
+	Predicate<ServerWebExchange> create(String value, String[] args);
 }

src/main/java/org/springframework/cloud/gateway/handler/predicate/HeaderPredicateFactory.java

@@ -0,0 +1,36 @@
+package org.springframework.cloud.gateway.handler.predicate;
+
+import java.util.List;
+import java.util.function.Predicate;
+
+import org.springframework.util.Assert;
+import org.springframework.web.server.ServerWebExchange;
+
+/**
+ * @author Spencer Gibb
+ */
+public class HeaderPredicateFactory implements GatewayPredicateFactory {
+
+	@Override
+	public String getName() {
+		return "Header";
+	}
+
+	@Override
+	public Predicate<ServerWebExchange> create(String header, String[] args) {
+		//TODO: caching can happen here
+		return exchange -> {
+			Assert.isTrue(args != null && args.length == 1,
+					"args must have one entry");
+
+			String regexp = args[0];
+			List<String> values = exchange.getRequest().getHeaders().get(header);
+			for (String value : values) {
+				if (value.matches(regexp)) {
+					return true;
+				}
+			}
+			return false;
+		};
+	}
+}

src/main/java/org/springframework/cloud/gateway/handler/predicate/HostPredicateFactory.java

@@ -23,7 +23,7 @@ public class HostPredicateFactory implements GatewayPredicateFactory {
 	}
 
 	@Override
-	public Predicate<ServerWebExchange> create(String pattern) {
+	public Predicate<ServerWebExchange> create(String pattern, String[] args) {
 		//TODO: caching can happen here
 		return exchange -> {
 			String host = exchange.getRequest().getHeaders().getFirst("Host");

src/main/java/org/springframework/cloud/gateway/handler/predicate/MethodPredicateFactory.java

@@ -16,7 +16,7 @@ public class MethodPredicateFactory implements GatewayPredicateFactory {
 	}
 
 	@Override
-	public Predicate<ServerWebExchange> create(String method) {
+	public Predicate<ServerWebExchange> create(String method, String[] args) {
 		//TODO: caching can happen here
 		return exchange -> {
 			HttpMethod requestMethod = exchange.getRequest().getMethod();

src/main/java/org/springframework/cloud/gateway/handler/predicate/UrlPredicateFactory.java

@@ -37,7 +37,7 @@ public class UrlPredicateFactory implements GatewayPredicateFactory {
 	}
 
 	@Override
-	public Predicate<ServerWebExchange> create(String pattern) {
+	public Predicate<ServerWebExchange> create(String pattern, String[] args) {
 		return exchange -> {
 			String lookupPath = getPathHelper().getLookupPathForRequest(exchange);
 			return getPathMatcher().match(pattern, lookupPath);

src/test/java/org/springframework/cloud/gateway/test/GatewayIntegrationTests.java

@@ -8,7 +8,7 @@ import org.springframework.boot.SpringBootConfiguration;
 import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
 import org.springframework.boot.context.embedded.LocalServerPort;
 import org.springframework.boot.test.context.SpringBootTest;
-import org.springframework.cloud.gateway.config.GatewayProperties.Route;
+import org.springframework.cloud.gateway.config.Route;
 import org.springframework.cloud.gateway.filter.GatewayFilter;
 import org.springframework.cloud.gateway.handler.ServerWebExchangePredicateHandlerMapping;
 import org.springframework.context.annotation.Bean;
@@ -88,6 +88,7 @@ public class GatewayIntegrationTests {
 		Mono<ClientResponse> result = webClient.exchange(
 				GET("http://localhost:" + port + "/headers")
 						.header("Host", "www.foo.org")
+						.header("X-Request-Id", "123")
 						.build()
 		);
 

src/test/resources/application.yml

@@ -7,19 +7,16 @@ spring:
       - id: host_example_to_httpbin
         downstreamUrl: http://httpbin.org:80
         predicates:
-        - name: Host
-          value: '**.example.org'
+        - Host=**.example.org
 
       # =====================================
       - id: host_foo_path_headers_to_httpbin
         downstreamUrl: http://httpbin.org:80
         predicates:
-        - name: Host
-          value: '**.foo.org'
-        - name: Url
-          value: /headers
-        - name: Method
-          value: GET
+        - Host=**.foo.org
+        - Url=/headers
+        - Method=GET
+        - Header=X-Request-Id, \d+
 
       # =====================================
       - id: default_path_to_httpbin