YARN-3601. Fix UT TestRMFailover.testRMWebAppRedirect. Contributed by Weiwei Yang

(cherry picked from commit 5009ad4a7f712fc578b461ecec53f7f97eaaed0c)

hadoop-yarn-project/CHANGES.txt

@@ -467,6 +467,8 @@ Release 2.7.1 - UNRELEASED
     YARN-3526. ApplicationMaster tracking URL is incorrectly redirected
     on a QJM cluster. (Weiwei Yang via xgong)
 
+    YARN-3601. Fix UT TestRMFailover.testRMWebAppRedirect. (Weiwei Yang via xgong)
+
 Release 2.7.0 - 2015-04-20
 
   INCOMPATIBLE CHANGES

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-client/src/test/java/org/apache/hadoop/yarn/client/TestRMFailover.java

@@ -21,13 +21,13 @@ package org.apache.hadoop.yarn.client;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.assertNull;
 import static org.junit.Assert.fail;
 
 import java.io.IOException;
 import java.net.HttpURLConnection;
 import java.net.URL;
-import java.util.List;
-import java.util.Map;
+import javax.servlet.http.HttpServletResponse;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
@@ -48,7 +48,6 @@ import org.apache.hadoop.yarn.server.webproxy.WebAppProxyServer;
 import org.junit.After;
 import org.junit.Assert;
 import org.junit.Before;
-import org.junit.Ignore;
 import org.junit.Test;
 
 public class TestRMFailover extends ClientBaseWithFixes {
@@ -275,10 +274,6 @@ public class TestRMFailover extends ClientBaseWithFixes {
     assertEquals(404, response.getResponseCode());
   }
 
-  // ignore this testcase, Always gets "too many redirect loops" exception
-  // Probably because of the limitation of MiniYARNCluster.
-  // Verified the behavior in a single node cluster.
-  @Ignore
   @Test
   public void testRMWebAppRedirect() throws YarnException,
       InterruptedException, IOException {
@@ -290,59 +285,62 @@ public class TestRMFailover extends ClientBaseWithFixes {
     getAdminService(0).transitionToActive(req);
     String rm1Url = "http://0.0.0.0:18088";
     String rm2Url = "http://0.0.0.0:28088";
-    String header = getHeader("Refresh", rm2Url);
-    assertTrue(header.contains("; url=" + rm1Url));
+    String redirectURL = getRedirectURL(rm2Url);
+    // if uri is null, RMWebAppFilter will append a slash at the trail of the redirection url
+    assertEquals(redirectURL,rm1Url+"/");
 
-    header = getHeader("Refresh", rm2Url + "/metrics");
-    assertTrue(header.contains("; url=" + rm1Url));
+    redirectURL = getRedirectURL(rm2Url + "/metrics");
+    assertEquals(redirectURL,rm1Url + "/metrics");
 
-    header = getHeader("Refresh", rm2Url + "/jmx");
-    assertTrue(header.contains("; url=" + rm1Url));
+    redirectURL = getRedirectURL(rm2Url + "/jmx");
+    assertEquals(redirectURL,rm1Url + "/jmx");
 
     // standby RM links /conf, /stacks, /logLevel, /static, /logs,
     // /cluster/cluster as well as webService
     // /ws/v1/cluster/info should not be redirected to active RM
-    header = getHeader("Refresh", rm2Url + "/cluster/cluster");
-    assertEquals(null, header);
+    redirectURL = getRedirectURL(rm2Url + "/cluster/cluster");
+    assertNull(redirectURL);
 
-    header = getHeader("Refresh", rm2Url + "/conf");
-    assertEquals(null, header);
+    redirectURL = getRedirectURL(rm2Url + "/conf");
+    assertNull(redirectURL);
 
-    header = getHeader("Refresh", rm2Url + "/stacks");
-    assertEquals(null, header);
+    redirectURL = getRedirectURL(rm2Url + "/stacks");
+    assertNull(redirectURL);
 
-    header = getHeader("Refresh", rm2Url + "/logLevel");
-    assertEquals(null, header);
+    redirectURL = getRedirectURL(rm2Url + "/logLevel");
+    assertNull(redirectURL);
 
-    header = getHeader("Refresh", rm2Url + "/static");
-    assertEquals(null, header);
+    redirectURL = getRedirectURL(rm2Url + "/static");
+    assertNull(redirectURL);
 
-    header = getHeader("Refresh", rm2Url + "/logs");
-    assertEquals(null, header);
+    redirectURL = getRedirectURL(rm2Url + "/logs");
+    assertNull(redirectURL);
 
-    header = getHeader("Refresh", rm2Url + "/ws/v1/cluster/info");
-    assertEquals(null, header);
+    redirectURL = getRedirectURL(rm2Url + "/ws/v1/cluster/info");
+    assertNull(redirectURL);
 
-    header = getHeader("Refresh", rm2Url + "/ws/v1/cluster/apps");
-    assertTrue(header.contains("; url=" + rm1Url));
+    redirectURL = getRedirectURL(rm2Url + "/ws/v1/cluster/apps");
+    assertEquals(redirectURL, rm1Url + "/ws/v1/cluster/apps");
 
-    header = getHeader("Refresh", rm2Url + "/proxy/" + fakeAppId);
-    assertEquals(null, header);
-
-    // Due to the limitation of MiniYARNCluster and dispatcher is a singleton,
-    // we couldn't add the test case after explicitFailover();
+    redirectURL = getRedirectURL(rm2Url + "/proxy/" + fakeAppId);
+    assertNull(redirectURL);
   }
 
-  static String getHeader(String field, String url) {
-    String fieldHeader = null;
+  // set up http connection with the given url and get the redirection url from the response
+  // return null if the url is not redirected
+  static String getRedirectURL(String url) {
+    String redirectUrl = null;
     try {
-      Map<String, List<String>> map =
-          new URL(url).openConnection().getHeaderFields();
-      fieldHeader = map.get(field).get(0);
+      HttpURLConnection conn = (HttpURLConnection) new URL(url).openConnection();
+      // do not automatically follow the redirection
+      // otherwise we get too many redirections exception
+      conn.setInstanceFollowRedirects(false);
+      if(conn.getResponseCode() == HttpServletResponse.SC_TEMPORARY_REDIRECT)
+        redirectUrl = conn.getHeaderField("Location");
     } catch (Exception e) {
       // throw new RuntimeException(e);
     }
-    return fieldHeader;
+    return redirectUrl;
   }
 
 }