Add support for X-Forwarded-Prefix to Zuul proxy

Fixes gh-43

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/zuul/ProxyRouteLocator.java

@@ -32,7 +32,7 @@ public class ProxyRouteLocator {
 
 	private AtomicReference<Map<String, ZuulRoute>> routes = new AtomicReference<>();
 
-	private Map<String, String> staticRoutes = new LinkedHashMap<String, String>();
+	private Map<String, ZuulRoute> staticRoutes = new LinkedHashMap<String, ZuulRoute>();
 
 	public ProxyRouteLocator(DiscoveryClient discovery, ZuulProperties properties) {
 		this.discovery = discovery;
@@ -40,7 +40,12 @@ public class ProxyRouteLocator {
 	}
 
 	public void addRoute(String path, String location) {
-		staticRoutes.put(path, location);
+		staticRoutes.put(path, new ZuulRoute(path, location));
+		resetRoutes();
+	}
+
+	public void addRoute(ZuulRoute route) {
+		staticRoutes.put(route.getPath(), route);
 		resetRoutes();
 	}
 
@@ -56,7 +61,7 @@ public class ProxyRouteLocator {
 
 		Map<String, String> values = new LinkedHashMap<String, String>();
 
-		for (String key : routes.get().keySet()) {			
+		for (String key : routes.get().keySet()) {
 			String url = key;
 			values.put(url, routes.get().get(key).getLocation());
 		}
@@ -67,26 +72,30 @@ public class ProxyRouteLocator {
 	public ProxyRouteSpec getMatchingRoute(String path) {
 		String location = null;
 		String targetPath = null;
+		String prefix = properties.getPrefix();
 		for (Entry<String, ZuulRoute> entry : routes.get().entrySet()) {
 			String pattern = entry.getKey();
 			if (pathMatcher.match(pattern, path)) {
 				ZuulRoute route = entry.getValue();
-				String prefix = properties.getPrefix();
 				location = route.getLocation();
 				targetPath = path;
 				if (path.startsWith(prefix) && properties.isStripPrefix()) {
 					targetPath = path.substring(prefix.length());
 				}
 				if (route.isStripPrefix()) {
-					int index = route.getPath().indexOf("*");
-					index = index > 0 ? index-1 : 0;
-					targetPath = path.substring(index);
+					int index = route.getPath().indexOf("*") - 1;
+					if (index > 0) {
+						targetPath = path.substring(prefix.length() + index);
+						prefix = prefix
+								+ path.substring(prefix.length(), prefix.length() + index);
+					}
 				}
+				break;
 			}
 		}
-		return location==null ? null : new ProxyRouteSpec(targetPath, location);
+		return location == null ? null : new ProxyRouteSpec(targetPath, location, prefix);
 	}
-	
+
 	// Package access so ZuulHandlerMapping can reset it's mappings
 	void resetRoutes() {
 		routes.set(locateRoutes());
@@ -97,7 +106,7 @@ public class ProxyRouteLocator {
 		LinkedHashMap<String, ZuulRoute> routesMap = new LinkedHashMap<>();
 
 		addConfiguredRoutes(routesMap);
-		addStaticRoutes(routesMap);
+		routesMap.putAll(staticRoutes);
 
 		// Add routes for discovery services by default
 		List<String> services = discovery.getServices();
@@ -120,7 +129,7 @@ public class ProxyRouteLocator {
 
 		LinkedHashMap<String, ZuulRoute> values = new LinkedHashMap<>();
 		for (Entry<String, ZuulRoute> entry : routesMap.entrySet()) {
-			
+
 			String path = entry.getKey();
 			// Prepend with slash if not already present.
 			if (!path.startsWith("/")) {
@@ -133,7 +142,7 @@ public class ProxyRouteLocator {
 					path = "/" + path;
 				}
 			}
-			
+
 			values.put(path, entry.getValue());
 
 		}
@@ -142,12 +151,6 @@ public class ProxyRouteLocator {
 
 	}
 
-	protected void addStaticRoutes(LinkedHashMap<String, ZuulRoute> routes) {
-		for (Entry<String, String> entry : staticRoutes.entrySet()) {
-			routes.put(entry.getKey(), new ZuulRoute(entry.getKey(), entry.getValue()));			
-		}
-	}
-
 	protected void addConfiguredRoutes(Map<String, ZuulRoute> routes) {
 		Map<String, ZuulRoute> routeEntries = properties.getRoutesWithDefaultServiceIds();
 		for (ZuulRoute entry : routeEntries.values()) {
@@ -162,13 +165,14 @@ public class ProxyRouteLocator {
 
 	public String getTargetPath(String matchingRoute, String requestURI) {
 		String path = getRoutes().get(matchingRoute);
-		if (path==null) {
+		if (path == null) {
 			path = requestURI;
-		} else {
-			
+		}
+		else {
+
 		}
 		return path;
-		
+
 	}
 
 	@Data
@@ -176,6 +180,7 @@ public class ProxyRouteLocator {
 	public static class ProxyRouteSpec {
 		private String path;
 		private String location;
+		private String prefix;
 	}
 
 }

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/zuul/filters/pre/PreDecorationFilter.java

@@ -10,6 +10,7 @@ import org.slf4j.LoggerFactory;
 import org.springframework.cloud.netflix.zuul.ProxyRouteLocator;
 import org.springframework.cloud.netflix.zuul.ProxyRouteLocator.ProxyRouteSpec;
 import org.springframework.cloud.netflix.zuul.ZuulProperties;
+import org.springframework.util.StringUtils;
 
 import com.netflix.zuul.ZuulFilter;
 import com.netflix.zuul.context.RequestContext;
@@ -49,7 +50,7 @@ public class PreDecorationFilter extends ZuulFilter {
 
 		ProxyRouteSpec route = routeLocator.getMatchingRoute(requestURI);
 
-		if (route!=null) {
+		if (route != null) {
 
 			String location = route.getLocation();
 
@@ -73,6 +74,9 @@ public class PreDecorationFilter extends ZuulFilter {
 							"X-Forwarded-Host",
 							ctx.getRequest().getServerName() + ":"
 									+ String.valueOf(ctx.getRequest().getServerPort()));
+					if (StringUtils.hasText(route.getPrefix())) {
+						ctx.addZuulRequestHeader("X-Forwarded-Prefix", route.getPrefix());
+					}
 				}
 			}
 		}

spring-cloud-netflix-core/src/test/java/org/springframework/cloud/netflix/zuul/filters/pre/PreDecorationFilterTests.java

@@ -0,0 +1,93 @@
+package org.springframework.cloud.netflix.zuul.filters.pre;
+
+import static org.junit.Assert.assertEquals;
+import static org.mockito.MockitoAnnotations.initMocks;
+
+import java.util.List;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.Mock;
+import org.springframework.cloud.client.discovery.DiscoveryClient;
+import org.springframework.cloud.netflix.zuul.ProxyRouteLocator;
+import org.springframework.cloud.netflix.zuul.ZuulProperties;
+import org.springframework.cloud.netflix.zuul.ZuulProperties.ZuulRoute;
+import org.springframework.mock.web.MockHttpServletRequest;
+
+import com.netflix.util.Pair;
+import com.netflix.zuul.context.RequestContext;
+
+/**
+ * @author Dave Syer
+ *
+ */
+public class PreDecorationFilterTests {
+	
+	private PreDecorationFilter filter;
+
+	@Mock
+	DiscoveryClient discovery;
+
+	private ZuulProperties properties = new ZuulProperties();
+
+	private ProxyRouteLocator routeLocator;
+	
+	private MockHttpServletRequest request = new MockHttpServletRequest();
+
+	@Before
+	public void init() {
+		initMocks(this);
+		routeLocator = new ProxyRouteLocator(discovery, properties);
+		filter = new PreDecorationFilter(routeLocator, properties);
+		RequestContext ctx = RequestContext.getCurrentContext();
+		ctx.setRequest(request);
+	}
+	
+	@Test
+	public void basicProperties() throws Exception {
+		assertEquals(5, filter.filterOrder());
+		assertEquals(true, filter.shouldFilter());
+		assertEquals("pre", filter.filterType());
+	}
+
+	@Test
+	public void prefixRouteAddsHeader() throws Exception {
+		properties.setPrefix("/api");
+		properties.setStripPrefix(true);
+		request.setRequestURI("/api/foo/1");
+		routeLocator.addRoute("/foo/**", "foo");
+		filter.run();
+		RequestContext ctx = RequestContext.getCurrentContext();
+		assertEquals("/foo/1", ctx.get("requestURI"));
+		assertEquals("localhost:80", ctx.getZuulRequestHeaders().get("x-forwarded-host"));
+		assertEquals("/api", ctx.getZuulRequestHeaders().get("x-forwarded-prefix"));
+		assertEquals("foo", getHeader(ctx.getOriginResponseHeaders(), "x-zuul-serviceid"));
+	}
+
+	@Test
+	public void prefixRouteWithRouteStrippingAddsHeader() throws Exception {
+		properties.setPrefix("/api");
+		properties.setStripPrefix(true);
+		request.setRequestURI("/api/foo/1");
+		routeLocator.addRoute(new ZuulRoute("/foo/**", "foo", null, true));
+		filter.run();
+		RequestContext ctx = RequestContext.getCurrentContext();
+		assertEquals("/1", ctx.get("requestURI"));
+		assertEquals("localhost:80", ctx.getZuulRequestHeaders().get("x-forwarded-host"));
+		assertEquals("/api/foo", ctx.getZuulRequestHeaders().get("x-forwarded-prefix"));
+		assertEquals("foo", getHeader(ctx.getOriginResponseHeaders(), "x-zuul-serviceid"));
+	}
+
+	private Object getHeader(List<Pair<String, String>> headers,
+			String key) {
+		String value = null;
+		for (Pair<String, String> pair : headers) {
+			if (pair.first().toLowerCase().equals(key.toLowerCase())) {
+				value = pair.second();
+				break;
+			}
+		}
+		return value;
+	}
+
+}