Add retryable property on Zuul route configuration

docs/src/main/asciidoc/spring-cloud-netflix.adoc

@@ -747,6 +747,12 @@ the service-specific prefix from individual routes, e.g.
 
 In this example requests to "/myusers/101" will be forwarded to "/myusers/101" on the "users" service.
 
+The `zuul.routes` entries actually bind to an object of type `ProxyRouteLocator`. If you
+look at the properties of that object you will see that it also has a "retryable" flag.
+Set that flag to "true" to have the Ribbon client automatically retry failed requests
+(and if you need to you can modify the parameters of the retry operations using
+the Ribbon client configuration).
+
 The `X-Forwarded-Host` header added to the forwarded requests by
 default.  To turn it off set `zuul.addProxyHeaders = false`.  The
 prefix path is stripped by default, and the request to the backend

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

@@ -88,6 +88,7 @@ public class ProxyRouteLocator implements RouteLocator {
 		String targetPath = null;
 		String id = null;
 		String prefix = this.properties.getPrefix();
+		Boolean retryable = this.properties.getRetryable();
 		for (Entry<String, ZuulRoute> entry : this.routes.get().entrySet()) {
 			String pattern = entry.getKey();
 			if (this.pathMatcher.match(pattern, path)) {
@@ -106,11 +107,14 @@ public class ProxyRouteLocator implements RouteLocator {
 						prefix = prefix + routePrefix;
 					}
 				}
+				if(route.getRetryable() != null) {
+					retryable = route.getRetryable();
+				}
 				break;
 			}
 		}
 		return (location == null ? null : new ProxyRouteSpec(id, targetPath, location,
-				prefix));
+				prefix, retryable));
 	}
 
 	public void resetRoutes() {
@@ -188,6 +192,8 @@ public class ProxyRouteLocator implements RouteLocator {
 
 		private String prefix;
 		
+		private Boolean retryable;
+
 	}
 
 }

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

@@ -43,6 +43,8 @@ public class ZuulProperties {
 
 	private boolean stripPrefix = true;
 	
+	private Boolean retryable;
+
 	private Map<String, ZuulRoute> routes = new LinkedHashMap<String, ZuulRoute>();
 
 	private boolean addProxyHeaders = true;
@@ -80,6 +82,8 @@ public class ZuulProperties {
 
 		private boolean stripPrefix = true;
 
+		private Boolean retryable;
+
 		public ZuulRoute(String text) {
 			String location = null;
 			String path = text;

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

@@ -67,6 +67,11 @@ public class PreDecorationFilter extends ZuulFilter {
 			if (location != null) {
 				ctx.put("requestURI", route.getPath());
 				ctx.put("proxy", route.getId());
+				
+				if (route.getRetryable() != null) {
+					ctx.put("retryable", route.getRetryable());
+				}
+				
 				if (location.startsWith("http:") || location.startsWith("https:")) {
 					ctx.setRouteHost(getUrl(location));
 					ctx.addOriginResponseHeader("X-Zuul-Service", location);

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/zuul/filters/route/RibbonCommand.java

@@ -53,6 +53,8 @@ public class RibbonCommand extends HystrixCommand<HttpResponse> {
 
 	private URI uri;
 	
+	private Boolean retryable;
+
 	private MultivaluedMap<String, String> headers;
 
 	private MultivaluedMap<String, String> params;
@@ -60,13 +62,15 @@ public class RibbonCommand extends HystrixCommand<HttpResponse> {
 	private InputStream requestEntity;
 
 	public RibbonCommand(RestClient restClient, Verb verb, String uri,
+			Boolean retryable,
 			MultivaluedMap<String, String> headers,
 			MultivaluedMap<String, String> params, InputStream requestEntity)
 			throws URISyntaxException {
-		this("default", restClient, verb, uri, headers, params, requestEntity);
+		this("default", restClient, verb, uri, retryable , headers, params, requestEntity);
 	}
 
 	public RibbonCommand(String commandKey, RestClient restClient, Verb verb, String uri,
+			Boolean retryable,
 			MultivaluedMap<String, String> headers,
 			MultivaluedMap<String, String> params, InputStream requestEntity)
 			throws URISyntaxException {
@@ -74,6 +78,7 @@ public class RibbonCommand extends HystrixCommand<HttpResponse> {
 		this.restClient = restClient;
 		this.verb = verb;
 		this.uri = new URI(uri);
+		this.retryable = retryable;
 		this.headers = headers;
 		this.params = params;
 		this.requestEntity = requestEntity;
@@ -102,6 +107,11 @@ public class RibbonCommand extends HystrixCommand<HttpResponse> {
 		RequestContext context = RequestContext.getCurrentContext();
 		Builder builder = HttpRequest.newBuilder().verb(this.verb).uri(this.uri)
 				.entity(this.requestEntity);
+		
+		if(retryable != null) {
+			builder.setRetriable(retryable);
+		}
+		
 		for (String name : this.headers.keySet()) {
 			List<String> values = this.headers.get(name);
 			for (String value : values) {

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/zuul/filters/route/RibbonRoutingFilter.java

@@ -94,6 +94,7 @@ public class RibbonRoutingFilter extends ZuulFilter {
 		InputStream requestEntity = getRequestBody(request);
 
 		String serviceId = (String) context.get("serviceId");
+		Boolean retryable = (Boolean) context.get("retryable");
 
 		RestClient restClient = this.clientFactory.getClient(serviceId, RestClient.class);
 
@@ -106,7 +107,7 @@ public class RibbonRoutingFilter extends ZuulFilter {
 		String service = (String) context.get("serviceId");
 
 		try {
-			HttpResponse response = forward(restClient, service, verb, uri, headers, params,
+			HttpResponse response = forward(restClient, service, verb, uri, retryable, headers, params,
 					requestEntity);
 			setResponse(response);
 			return response;
@@ -118,12 +119,12 @@ public class RibbonRoutingFilter extends ZuulFilter {
 		return null;
 	}
 
-	private HttpResponse forward(RestClient restClient, String service, Verb verb, String uri,
+	private HttpResponse forward(RestClient restClient, String service, Verb verb, String uri, Boolean retryable,
 			MultiValueMap<String, String> headers, MultiValueMap<String, String> params,
 			InputStream requestEntity) throws Exception {
 		Map<String, Object> info = this.helper.debug(verb.verb(), uri, headers, params,
 				requestEntity);
-		RibbonCommand command = new RibbonCommand(service, restClient, verb, uri,
+		RibbonCommand command = new RibbonCommand(service, restClient, verb, uri, retryable,
 				convertHeaders(headers), convertHeaders(params), requestEntity);
 		try {
 			HttpResponse response = command.execute();

spring-cloud-netflix-core/src/test/java/org/springframework/cloud/netflix/zuul/RetryableZuulProxyApplicationTests.java

+package org.springframework.cloud.netflix.zuul;
+
+import static org.junit.Assert.assertEquals;
+
+import java.util.Arrays;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.boot.test.IntegrationTest;
+import org.springframework.boot.test.SpringApplicationConfiguration;
+import org.springframework.boot.test.TestRestTemplate;
+import org.springframework.cloud.netflix.ribbon.RibbonClient;
+import org.springframework.cloud.netflix.zuul.filters.ProxyRouteLocator;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.http.HttpEntity;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpMethod;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.MediaType;
+import org.springframework.http.ResponseEntity;
+import org.springframework.test.annotation.DirtiesContext;
+import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+import org.springframework.test.context.web.WebAppConfiguration;
+import org.springframework.util.LinkedMultiValueMap;
+import org.springframework.util.MultiValueMap;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestMethod;
+import org.springframework.web.bind.annotation.RestController;
+
+import com.netflix.appinfo.EurekaInstanceConfig;
+import com.netflix.loadbalancer.BaseLoadBalancer;
+import com.netflix.loadbalancer.ILoadBalancer;
+import com.netflix.loadbalancer.Server;
+import com.netflix.zuul.ZuulFilter;
+
+@RunWith(SpringJUnit4ClassRunner.class)
+@SpringApplicationConfiguration(classes = RetryableZuulProxyApplication.class)
+@WebAppConfiguration
+@IntegrationTest({ "server.port: 0",
+		"zuul.routes.simple.path: /simple/**",
+		"zuul.routes.simple.retryable: true",
+		"ribbon.OkToRetryOnAllOperations: true"
+})
+@DirtiesContext
+public class RetryableZuulProxyApplicationTests {
+
+		@Value("${local.server.port}")
+		private int port;
+
+		@Autowired
+		private ProxyRouteLocator routes;
+
+		@Autowired
+		private RoutesEndpoint endpoint;
+
+		@Test
+		public void postWithForm() {
+				MultiValueMap<String, String> form = new LinkedMultiValueMap<String, String>();
+				form.set("foo", "bar");
+				HttpHeaders headers = new HttpHeaders();
+				headers.setContentType(MediaType.APPLICATION_FORM_URLENCODED);
+				ResponseEntity<String> result = new TestRestTemplate().exchange(
+						"http://localhost:" + port + "/simple", HttpMethod.POST,
+						new HttpEntity<MultiValueMap<String,String>>(form, headers), String.class);
+				assertEquals(HttpStatus.OK, result.getStatusCode());
+				assertEquals("Posted! {foo=[bar]}", result.getBody());
+		}
+
+}
+
+//Don't use @SpringBootApplication because we don't want to component scan
+@Configuration
+@EnableAutoConfiguration
+@RestController
+@EnableZuulProxy
+@RibbonClient(name = "simple", configuration = RetryableRibbonClientConfiguration.class)
+class RetryableZuulProxyApplication {
+
+		@RequestMapping(value = "/", method = RequestMethod.POST)
+		public String delete(@RequestBody MultiValueMap<String, String> form) {
+				return "Posted! " + form;
+		}
+
+		@Bean
+		public ZuulFilter sampleFilter() {
+				return new ZuulFilter() {
+						@Override
+						public String filterType() {
+								return "pre";
+						}
+
+						@Override
+						public boolean shouldFilter() {
+								return true;
+						}
+
+						@Override
+						public Object run() {
+								return null;
+						}
+
+						@Override
+						public int filterOrder() {
+								return 0;
+						}
+				};
+		}
+
+		public static void main(String[] args) {
+				SpringApplication.run(SampleZuulProxyApplication.class, args);
+		}
+
+}
+
+//Load balancer with fixed server list for "simple" pointing to localhost
+@Configuration
+class RetryableRibbonClientConfiguration {
+		@Bean
+		public ILoadBalancer ribbonLoadBalancer(EurekaInstanceConfig instance) {
+				BaseLoadBalancer balancer = new BaseLoadBalancer();
+				balancer.setServersList(Arrays.asList(
+						new Server("localhost", instance.getNonSecurePort()),
+						new Server("failed-localhost", instance.getNonSecurePort())
+				));
+				return balancer;
+		}
+}
\ No newline at end of file

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

@@ -89,7 +89,7 @@ public class ProxyRouteLocatorTests {
 		ProxyRouteLocator routeLocator = new ProxyRouteLocator(this.discovery,
 				this.properties);
 		this.properties.getRoutes().put("foo",
-				new ZuulRoute("foo", "/foo/**", "foo", null, false));
+				new ZuulRoute("foo", "/foo/**", "foo", null, false, null));
 		this.properties.setStripPrefix(false);
 		this.properties.setPrefix("/proxy");
 		routeLocator.getRoutes(); // force refresh
@@ -116,7 +116,7 @@ public class ProxyRouteLocatorTests {
 		ProxyRouteLocator routeLocator = new ProxyRouteLocator(this.discovery,
 				this.properties);
 		this.properties.getRoutes().put("foo",
-				new ZuulRoute("foo", "/foo/**", "foo", null, false));
+				new ZuulRoute("foo", "/foo/**", "foo", null, false, null));
 		this.properties.setPrefix("/proxy");
 		routeLocator.getRoutes(); // force refresh
 		ProxyRouteSpec route = routeLocator.getMatchingRoute("/proxy/foo/1");

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

@@ -70,7 +70,7 @@ public class PreDecorationFilterTests {
 		this.properties.setPrefix("/api");
 		this.properties.setStripPrefix(true);
 		this.request.setRequestURI("/api/foo/1");
-		this.routeLocator.addRoute(new ZuulRoute("foo", "/foo/**", "foo", null, false));
+		this.routeLocator.addRoute(new ZuulRoute("foo", "/foo/**", "foo", null, false, null));
 		this.filter.run();
 		RequestContext ctx = RequestContext.getCurrentContext();
 		assertEquals("/foo/1", ctx.get("requestURI"));