Use loopback network interface for testcases.

bookkeeper-server/src/test/java/org/apache/bookkeeper/bookie/BookieInitializationTest.java

@@ -155,7 +155,7 @@ public void testBookieRegistrationWithSameZooKeeperClient() throws Exception {
         final ServerConfiguration conf = TestBKConfiguration.newServerConfiguration();
         conf.setJournalDirName(tmpDir.getPath())
             .setLedgerDirNames(new String[] { tmpDir.getPath() })
-            .setZkServers(null);
+            .setZkServers(null).setListeningInterface(null);
 
         final String bkRegPath = conf.getZkAvailableBookiesPath() + "/"
                 + InetAddress.getLocalHost().getHostAddress() + ":"
@@ -188,7 +188,7 @@ public void testBookieRegistration() throws Exception {
         final ServerConfiguration conf = TestBKConfiguration.newServerConfiguration();
         conf.setJournalDirName(tmpDir.getPath())
             .setLedgerDirNames(new String[] { tmpDir.getPath() })
-            .setZkServers(null);
+            .setZkServers(null).setListeningInterface(null);
 
         final String bkRegPath = conf.getZkAvailableBookiesPath() + "/"
                 + InetAddress.getLocalHost().getHostAddress() + ":"
@@ -250,7 +250,7 @@ public void testBookieRegistrationWithFQDNHostNameAsBookieID() throws Exception
 
         final ServerConfiguration conf = TestBKConfiguration.newServerConfiguration().setZkServers(null)
                 .setJournalDirName(tmpDir.getPath()).setLedgerDirNames(new String[] { tmpDir.getPath() })
-                .setUseHostNameAsBookieID(true);
+                .setUseHostNameAsBookieID(true).setListeningInterface(null);
 
         final String bkRegPath = conf.getZkAvailableBookiesPath() + "/"
                 + InetAddress.getLocalHost().getCanonicalHostName() + ":" + conf.getBookiePort();
@@ -271,7 +271,7 @@ public void testBookieRegistrationWithShortHostNameAsBookieID() throws Exception
 
         final ServerConfiguration conf = TestBKConfiguration.newServerConfiguration().setZkServers(null)
                 .setJournalDirName(tmpDir.getPath()).setLedgerDirNames(new String[] { tmpDir.getPath() })
-                .setUseHostNameAsBookieID(true).setUseShortHostName(true);
+                .setUseHostNameAsBookieID(true).setUseShortHostName(true).setListeningInterface(null);
 
         final String bkRegPath = conf.getZkAvailableBookiesPath() + "/"
                 + (InetAddress.getLocalHost().getCanonicalHostName().split("\\.", 2)[0]) + ":" + conf.getBookiePort();
@@ -298,7 +298,8 @@ public void testRegNodeExistsAfterSessionTimeOut() throws Exception {
         final ServerConfiguration conf = TestBKConfiguration.newServerConfiguration();
         conf.setJournalDirName(tmpDir.getPath())
             .setLedgerDirNames(new String[] { tmpDir.getPath() })
-            .setZkServers(zkUtil.getZooKeeperConnectString());
+            .setZkServers(zkUtil.getZooKeeperConnectString())
+            .setListeningInterface(null);
 
         String bkRegPath = conf.getZkAvailableBookiesPath() + "/"
                 + InetAddress.getLocalHost().getHostAddress() + ":"

bookkeeper-server/src/test/java/org/apache/bookkeeper/bookie/storage/ldb/ConversionRollbackTest.java

@@ -40,6 +40,7 @@
 import org.apache.bookkeeper.bookie.InterleavedLedgerStorage;
 import org.apache.bookkeeper.bookie.LedgerDirsManager;
 import org.apache.bookkeeper.conf.ServerConfiguration;
+import org.apache.bookkeeper.conf.TestBKConfiguration;
 import org.apache.bookkeeper.stats.NullStatsLogger;
 import org.apache.bookkeeper.util.DiskChecker;
 import org.apache.commons.io.FileUtils;
@@ -81,9 +82,8 @@ public void convertFromDbStorageToInterleaved() throws Exception {
 
         log.info("Using temp directory: {}", tmpDir);
 
-        ServerConfiguration conf = new ServerConfiguration();
+        ServerConfiguration conf = TestBKConfiguration.newServerConfiguration();
         conf.setLedgerDirNames(new String[] { tmpDir.toString() });
-        conf.setAllowLoopback(true);
         LedgerDirsManager ledgerDirsManager = new LedgerDirsManager(conf, conf.getLedgerDirs(),
                 new DiskChecker(conf.getDiskUsageThreshold(), conf.getDiskUsageWarnThreshold()));
 

bookkeeper-server/src/test/java/org/apache/bookkeeper/bookie/storage/ldb/ConversionTest.java

@@ -39,6 +39,7 @@
 import org.apache.bookkeeper.bookie.InterleavedLedgerStorage;
 import org.apache.bookkeeper.bookie.LedgerDirsManager;
 import org.apache.bookkeeper.conf.ServerConfiguration;
+import org.apache.bookkeeper.conf.TestBKConfiguration;
 import org.apache.bookkeeper.stats.NullStatsLogger;
 import org.apache.bookkeeper.util.DiskChecker;
 import org.apache.commons.io.FileUtils;
@@ -78,9 +79,8 @@ public void test() throws Exception {
 
         System.out.println(tmpDir);
 
-        ServerConfiguration conf = new ServerConfiguration();
+        ServerConfiguration conf = TestBKConfiguration.newServerConfiguration();
         conf.setLedgerDirNames(new String[] { tmpDir.toString() });
-        conf.setAllowLoopback(true);
         LedgerDirsManager ledgerDirsManager = new LedgerDirsManager(conf, conf.getLedgerDirs(),
                 new DiskChecker(conf.getDiskUsageThreshold(), conf.getDiskUsageWarnThreshold()));
 

bookkeeper-server/src/test/java/org/apache/bookkeeper/bookie/storage/ldb/DbLedgerStorageTest.java

@@ -40,6 +40,7 @@
 import org.apache.bookkeeper.bookie.EntryLocation;
 import org.apache.bookkeeper.bookie.EntryLogger;
 import org.apache.bookkeeper.conf.ServerConfiguration;
+import org.apache.bookkeeper.conf.TestBKConfiguration;
 import org.apache.bookkeeper.proto.BookieProtocol;
 import org.junit.After;
 import org.junit.Before;
@@ -62,9 +63,8 @@ public void setup() throws Exception {
         Bookie.checkDirectoryStructure(curDir);
 
         int gcWaitTime = 1000;
-        ServerConfiguration conf = new ServerConfiguration();
+        ServerConfiguration conf = TestBKConfiguration.newServerConfiguration();
         conf.setGcWaitTime(gcWaitTime);
-        conf.setAllowLoopback(true);
         conf.setLedgerStorageClass(DbLedgerStorage.class.getName());
         conf.setLedgerDirNames(new String[] { tmpDir.toString() });
         Bookie bookie = new Bookie(conf);
@@ -229,9 +229,8 @@ public void testBookieCompaction() throws Exception {
     @Test
     public void doubleDirectoryError() throws Exception {
         int gcWaitTime = 1000;
-        ServerConfiguration conf = new ServerConfiguration();
+        ServerConfiguration conf = TestBKConfiguration.newServerConfiguration();
         conf.setGcWaitTime(gcWaitTime);
-        conf.setAllowLoopback(true);
         conf.setLedgerStorageClass(DbLedgerStorage.class.getName());
         conf.setLedgerDirNames(new String[] { "dir1", "dir2" });
 

bookkeeper-server/src/test/java/org/apache/bookkeeper/bookie/storage/ldb/DbLedgerStorageWriteCacheTest.java

@@ -31,6 +31,7 @@
 
 import org.apache.bookkeeper.bookie.Bookie;
 import org.apache.bookkeeper.conf.ServerConfiguration;
+import org.apache.bookkeeper.conf.TestBKConfiguration;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
@@ -79,9 +80,8 @@ public void setup() throws Exception {
         Bookie.checkDirectoryStructure(curDir);
 
         int gcWaitTime = 1000;
-        ServerConfiguration conf = new ServerConfiguration();
+        ServerConfiguration conf = TestBKConfiguration.newServerConfiguration();
         conf.setGcWaitTime(gcWaitTime);
-        conf.setAllowLoopback(true);
         conf.setLedgerStorageClass(MockedDbLedgerStorage.class.getName());
         conf.setProperty(DbLedgerStorage.WRITE_CACHE_MAX_SIZE_MB, 1);
         conf.setLedgerDirNames(new String[] { tmpDir.toString() });

bookkeeper-server/src/test/java/org/apache/bookkeeper/bookie/storage/ldb/LocationsIndexRebuildTest.java

@@ -39,6 +39,7 @@
 import org.apache.bookkeeper.bookie.Checkpointer;
 import org.apache.bookkeeper.bookie.LedgerDirsManager;
 import org.apache.bookkeeper.conf.ServerConfiguration;
+import org.apache.bookkeeper.conf.TestBKConfiguration;
 import org.apache.bookkeeper.stats.NullStatsLogger;
 import org.apache.bookkeeper.util.DiskChecker;
 import org.apache.commons.io.FileUtils;
@@ -78,10 +79,9 @@ public void test() throws Exception {
 
         System.out.println(tmpDir);
 
-        ServerConfiguration conf = new ServerConfiguration();
+        ServerConfiguration conf = TestBKConfiguration.newServerConfiguration();
         conf.setLedgerDirNames(new String[] { tmpDir.toString() });
         conf.setLedgerStorageClass(DbLedgerStorage.class.getName());
-        conf.setAllowLoopback(true);
         LedgerDirsManager ledgerDirsManager = new LedgerDirsManager(conf, conf.getLedgerDirs(),
                 new DiskChecker(conf.getDiskUsageThreshold(), conf.getDiskUsageWarnThreshold()));
 

bookkeeper-server/src/test/java/org/apache/bookkeeper/client/UpdateLedgerCmdTest.java

@@ -53,7 +53,6 @@ public class UpdateLedgerCmdTest extends BookKeeperClusterTestCase {
 
     public UpdateLedgerCmdTest() {
         super(3);
-        baseConf.setAllowLoopback(true);
         baseConf.setGcWaitTime(100000);
     }
 

bookkeeper-server/src/test/java/org/apache/bookkeeper/conf/TestBKConfiguration.java

@@ -21,23 +21,61 @@
 
 package org.apache.bookkeeper.conf;
 
+import java.net.NetworkInterface;
+import java.net.SocketException;
+import java.util.Collections;
+import java.util.Enumeration;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 /**
  * Test the BK configuration object.
  */
 public class TestBKConfiguration {
 
+    static final Logger LOG = LoggerFactory.getLogger(TestBKConfiguration.class);
+
+    /**
+     * Loopback interface is set as the listening interface and allowloopback is
+     * set to true in this server config.
+     *
+     * <p>If the caller doesn't want loopback address, then listeningInterface
+     * should be set back to null.
+     */
     public static ServerConfiguration newServerConfiguration() {
         ServerConfiguration confReturn = new ServerConfiguration();
         confReturn.setJournalFlushWhenQueueEmpty(true);
         // enable journal format version
         confReturn.setJournalFormatVersionToWrite(5);
-        confReturn.setAllowLoopback(true);
         confReturn.setAllowEphemeralPorts(true);
         confReturn.setBookiePort(0);
         confReturn.setGcWaitTime(1000);
         confReturn.setDiskUsageThreshold(0.999f);
         confReturn.setDiskUsageWarnThreshold(0.99f);
+        setLoopbackInterfaceAndAllowLoopback(confReturn);
         return confReturn;
     }
 
+    private static String getLoopbackInterfaceName() {
+        try {
+            Enumeration<NetworkInterface> nifs = NetworkInterface.getNetworkInterfaces();
+            for (NetworkInterface nif : Collections.list(nifs)) {
+                if (nif.isLoopback()) {
+                    return nif.getName();
+                }
+            }
+        } catch (SocketException se) {
+            LOG.warn("Exception while figuring out loopback interface. Will use null.", se);
+            return null;
+        }
+        LOG.warn("Unable to deduce loopback interface. Will use null");
+        return null;
+    }
+
+    public static ServerConfiguration setLoopbackInterfaceAndAllowLoopback(ServerConfiguration serverConf) {
+        serverConf.setListeningInterface(getLoopbackInterfaceName());
+        serverConf.setAllowLoopback(true);
+        return serverConf;
+    }
 }

bookkeeper-server/src/test/java/org/apache/bookkeeper/test/BookKeeperClusterTestCase.java

@@ -85,6 +85,11 @@ public abstract class BookKeeperClusterTestCase {
     protected int numBookies;
     protected BookKeeperTestClient bkc;
 
+    /*
+     * Loopback interface is set as the listening interface and allowloopback is
+     * set to true in this server config. So bookies in this test process would
+     * bind to loopback address.
+     */
     protected final ServerConfiguration baseConf = TestBKConfiguration.newServerConfiguration();
     protected final ClientConfiguration baseClientConf = new ClientConfiguration();
 
@@ -99,7 +104,6 @@ public BookKeeperClusterTestCase(int numBookies) {
     public BookKeeperClusterTestCase(int numBookies, int testTimeoutSecs) {
         this.numBookies = numBookies;
         this.globalTimeout = Timeout.seconds(testTimeoutSecs);
-        baseConf.setAllowLoopback(true);
     }
 
     @Before