From bdcbc2d1ef0fba999170ba748176ad0f496ccf2c Mon Sep 17 00:00:00 2001
From: Todd Lipcon <todd@apache.org>
Date: Tue, 11 Sep 2012 06:37:17 +0000
Subject: [PATCH] HADOOP-8786. HttpServer continues to start even if
 AuthenticationFilter fails to init. Contributed by Todd Lipcon.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1383254 13f79535-47bb-0310-9956-ffa450edef68
---
 .../hadoop-common/CHANGES.txt                 |  3 +++
 .../org/apache/hadoop/http/HttpServer.java    |  9 +++++++
 .../apache/hadoop/http/TestServletFilter.java | 24 ++++++++++++++++++-
 3 files changed, 35 insertions(+), 1 deletion(-)

diff --git a/hadoop-common-project/hadoop-common/CHANGES.txt b/hadoop-common-project/hadoop-common/CHANGES.txt
index c7848aaad0..08a8d1240d 100644
--- a/hadoop-common-project/hadoop-common/CHANGES.txt
+++ b/hadoop-common-project/hadoop-common/CHANGES.txt
@@ -202,6 +202,9 @@ Trunk (Unreleased)
     HADOOP-8684. Deadlock between WritableComparator and WritableComparable.
     (Jing Zhao via suresh)
 
+    HADOOP-8786. HttpServer continues to start even if AuthenticationFilter
+    fails to init (todd)
+
   OPTIMIZATIONS
 
     HADOOP-7761. Improve the performance of raw comparisons. (todd)
diff --git a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/http/HttpServer.java b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/http/HttpServer.java
index 77e9e1601a..0de1806a4d 100644
--- a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/http/HttpServer.java
+++ b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/http/HttpServer.java
@@ -677,6 +677,15 @@ public void start() throws IOException {
               "Problem in starting http server. Server handlers failed");
         }
       }
+      // Make sure there are no errors initializing the context.
+      Throwable unavailableException = webAppContext.getUnavailableException();
+      if (unavailableException != null) {
+        // Have to stop the webserver, or else its non-daemon threads
+        // will hang forever.
+        webServer.stop();
+        throw new IOException("Unable to initialize WebAppContext",
+            unavailableException);
+      }
     } catch (IOException e) {
       throw e;
     } catch (InterruptedException e) {
diff --git a/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/http/TestServletFilter.java b/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/http/TestServletFilter.java
index a4d32531ce..e5392396d5 100644
--- a/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/http/TestServletFilter.java
+++ b/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/http/TestServletFilter.java
@@ -35,6 +35,7 @@
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.test.GenericTestUtils;
 import org.junit.Test;
 
 public class TestServletFilter extends HttpServerFunctionalTest {
@@ -163,7 +164,7 @@ public void initFilter(FilterContainer container, Configuration conf) {
   @Test
   public void testServletFilterWhenInitThrowsException() throws Exception {
     Configuration conf = new Configuration();
-    // start a http server with CountingFilter
+    // start a http server with ErrorFilter
     conf.set(HttpServer.FILTER_INITIALIZER_PROPERTY,
         ErrorFilter.Initializer.class.getName());
     HttpServer http = createTestServer(conf);
@@ -174,4 +175,25 @@ public void testServletFilterWhenInitThrowsException() throws Exception {
       assertTrue( e.getMessage().contains("Problem in starting http server. Server handlers failed"));
     }
   }
+  
+  /**
+   * Similar to the above test case, except that it uses a different API to add the
+   * filter. Regression test for HADOOP-8786.
+   */
+  @Test
+  public void testContextSpecificServletFilterWhenInitThrowsException()
+      throws Exception {
+    Configuration conf = new Configuration();
+    HttpServer http = createTestServer(conf);
+    http.defineFilter(http.webAppContext,
+        "ErrorFilter", ErrorFilter.class.getName(),
+        null, null);
+    try {
+      http.start();
+      fail("expecting exception");
+    } catch (IOException e) {
+      GenericTestUtils.assertExceptionContains("Unable to initialize WebAppContext", e);
+    }
+  }
+
 }