ZOOKEEPER-4886: Fix observer with small myid can't join SASL quorum

Reviewers: kezhuw, anmolnar
Author: zichen-gan
Closes #2211 from zichen-gan/SASLSmallObserverCanotJion

zookeeper-server/src/main/java/org/apache/zookeeper/server/quorum/QuorumCnxManager.java

@@ -503,7 +503,7 @@ public class QuorumCnxManager {
         }
 
         // authenticate learner
-        QuorumPeer.QuorumServer qps = self.getVotingView().get(sid);
+        QuorumPeer.QuorumServer qps = self.getView().get(sid);
         if (qps != null) {
             // TODO - investigate why reconfig makes qps null.
             authLearner.authenticate(sock, qps.hostname);

zookeeper-server/src/test/java/org/apache/zookeeper/server/quorum/auth/QuorumAuthObserverTest.java

@@ -0,0 +1,87 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.zookeeper.server.quorum.auth;
+
+import java.util.HashMap;
+import java.util.Map;
+import org.apache.zookeeper.CreateMode;
+import org.apache.zookeeper.ZooDefs.Ids;
+import org.apache.zookeeper.ZooKeeper;
+import org.apache.zookeeper.test.ClientBase;
+import org.apache.zookeeper.test.ClientBase.CountdownWatcher;
+import org.junit.jupiter.api.AfterAll;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.Test;
+
+public class QuorumAuthObserverTest extends DigestSecurityTestcase {
+
+    static {
+        String jaasEntries = "QuorumServer {\n"
+                             + "       org.apache.zookeeper.server.auth.DigestLoginModule required\n"
+                             + "       user_test=\"mypassword\";\n"
+                             + "};\n"
+                             + "QuorumLearner {\n"
+                             + "       org.apache.zookeeper.server.auth.DigestLoginModule required\n"
+                             + "       username=\"test\"\n"
+                             + "       password=\"mypassword\";\n"
+                             + "};\n";
+        setupJaasConfig(jaasEntries);
+    }
+
+    @AfterEach
+    @Override
+    public void tearDown() throws Exception {
+        shutdownAll();
+        super.tearDown();
+    }
+
+    @AfterAll
+    public static void cleanup() {
+        cleanupJaasConfig();
+    }
+
+    /**
+     * Test to ensure observer with small myid can join SASL quorum.
+     * peer0 myid：11 participant
+     * peer1 myid：21 participant
+     * peer2 myid：1 observer
+     */
+    @Test
+    public void testSmallObserverJoinSASLQuorum() throws Exception {
+        Map<String, String> authConfigs = new HashMap<>();
+        authConfigs.put(QuorumAuth.QUORUM_SASL_AUTH_ENABLED, "true");
+        authConfigs.put(QuorumAuth.QUORUM_SERVER_SASL_AUTH_REQUIRED, "true");
+        authConfigs.put(QuorumAuth.QUORUM_LEARNER_SASL_AUTH_REQUIRED, "true");
+
+        // create quorum
+        StringBuilder connectStringBuilder = new StringBuilder();
+        int[] myidList = {11, 21, 1};
+        String[] roleList = {"participant", "participant", "observer"};
+        int[] clientPorts = startQuorum(3, connectStringBuilder, authConfigs, 3, false, myidList, roleList);
+
+        // observer with small myid should have joined the quorum
+        String connectStr = "127.0.0.1:" + clientPorts[2];
+        CountdownWatcher watcher = new CountdownWatcher();
+        ZooKeeper zk = new ZooKeeper(connectStr, ClientBase.CONNECTION_TIMEOUT, watcher);
+        watcher.waitForConnected(ClientBase.CONNECTION_TIMEOUT);
+
+        zk.create("/foo", new byte[0], Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
+        zk.close();
+    }
+}

zookeeper-server/src/test/java/org/apache/zookeeper/server/quorum/auth/QuorumAuthTestBase.java

@@ -103,16 +103,28 @@ public class QuorumAuthTestBase extends ZKTestCase {
     }
 
     protected int[] startQuorum(final int serverCount, StringBuilder connectStr, Map<String, String> authConfigs,
-        int authServerCount, boolean multiAddress) throws IOException {
+                                int authServerCount, boolean multiAddress) throws IOException {
+        int[] defaultMyidList = new int[serverCount];
+        String[] defaultRoleList = new String[serverCount];
+        for (int i = 0; i < serverCount; i++) {
+            defaultMyidList[i] = i;
+            defaultRoleList[i] = "participant";
+        }
+        return startQuorum(serverCount, connectStr, authConfigs, authServerCount, multiAddress, defaultMyidList, defaultRoleList);
+    }
+
+    protected int[] startQuorum(final int serverCount, StringBuilder connectStr, Map<String, String> authConfigs,
+        int authServerCount, boolean multiAddress, int[] myidList, String[] roleList) throws IOException {
         final int[] clientPorts = new int[serverCount];
         StringBuilder sb = new StringBuilder();
         for (int i = 0; i < serverCount; i++) {
             clientPorts[i] = PortAssignment.unique();
-            String server = String.format("server.%d=localhost:%d:%d", i, PortAssignment.unique(), PortAssignment.unique());
+            String server = String.format("server.%d=localhost:%d:%d", myidList[i], PortAssignment.unique(), PortAssignment.unique());
             if (multiAddress) {
                 server = server + String.format("|localhost:%d:%d", PortAssignment.unique(), PortAssignment.unique());
             }
-            sb.append(server + ":participant\n");
+
+            sb.append(server + ":" + roleList[i] + "\n");
             connectStr.append("127.0.0.1:" + clientPorts[i]);
             if (i < serverCount - 1) {
                 connectStr.append(",");
@@ -122,11 +134,11 @@ public class QuorumAuthTestBase extends ZKTestCase {
         // servers with authentication interfaces configured
         int i = 0;
         for (; i < authServerCount; i++) {
-            startServer(authConfigs, clientPorts, quorumCfg, i);
+            startServer(authConfigs, clientPorts, quorumCfg, i, myidList);
         }
         // servers without any authentication configured
         for (int j = 0; j < serverCount - authServerCount; j++, i++) {
-            MainThread mthread = new MainThread(i, clientPorts[i], quorumCfg);
+            MainThread mthread = new MainThread(myidList[i], clientPorts[i], quorumCfg);
             mt.add(mthread);
             mthread.start();
         }
@@ -137,8 +149,9 @@ public class QuorumAuthTestBase extends ZKTestCase {
         Map<String, String> authConfigs,
         final int[] clientPorts,
         String quorumCfg,
-        int i) throws IOException {
-        MainThread mthread = new MainThread(i, clientPorts[i], quorumCfg, authConfigs);
+        int i,
+        int[] myidList) throws IOException {
+        MainThread mthread = new MainThread(myidList[i], clientPorts[i], quorumCfg, authConfigs);
         mt.add(mthread);
         mthread.start();
     }
@@ -149,6 +162,16 @@ public class QuorumAuthTestBase extends ZKTestCase {
         mthread.start();
     }
 
+    protected void startServer(
+            Map<String, String> authConfigs,
+            final int clientPort,
+            String quorumCfg,
+            int myid) throws IOException {
+        MainThread mthread = new MainThread(myid, clientPort, quorumCfg, authConfigs);
+        mt.add(mthread);
+        mthread.start();
+    }
+
     void shutdownAll() {
         for (int i = 0; i < mt.size(); i++) {
             shutdown(i);