Allow providing a chroot to ZK suppliers (apache#5281)

* Add support to ClientInfo (and implementations) for providing a chroot
  path to the ZooKeeper (ZooSession) supplier
* Fix typo in two ZooSession client names to lookup the instanceId or
  instanceName from the other (the client names were the reverse of the
  operation being performed, creating a little confusion in the logs)

Author: ctubbsii

core/src/main/java/org/apache/accumulo/core/clientImpl/ClientContext.java

@@ -224,7 +224,8 @@ public ClientContext(SingletonReservation reservation, ClientInfo info,
 
     this.zooSession = memoize(() -> {
       var zk = info
-          .getZooKeeperSupplier(getClass().getSimpleName() + "(" + info.getPrincipal() + ")").get();
+          .getZooKeeperSupplier(getClass().getSimpleName() + "(" + info.getPrincipal() + ")", "")
+          .get();
       zooKeeperOpened.set(true);
       return zk;
     });
@@ -1100,7 +1101,7 @@ public synchronized ZookeeperLockChecker getTServerLockChecker() {
       // so, it can't rely on being able to continue to use the same client's ZooCache,
       // because that client could be closed, and its ZooSession also closed
       // this needs to be fixed; TODO https://github.com/apache/accumulo/issues/2301
-      var zk = info.getZooKeeperSupplier(ZookeeperLockChecker.class.getSimpleName()).get();
+      var zk = info.getZooKeeperSupplier(ZookeeperLockChecker.class.getSimpleName(), "").get();
       this.zkLockChecker =
           new ZookeeperLockChecker(new ZooCache(zk), getZooKeeperRoot() + Constants.ZTSERVERS);
     }

core/src/main/java/org/apache/accumulo/core/clientImpl/ClientInfo.java

@@ -50,7 +50,7 @@ public interface ClientInfo {
   /**
    * @return a Supplier for creating new ZooKeeper client instances based on the configuration
    */
-  Supplier<ZooSession> getZooKeeperSupplier(String clientName);
+  Supplier<ZooSession> getZooKeeperSupplier(String clientName, String rootPath);
 
   /**
    * @return Zookeeper connection information for Accumulo instance

core/src/main/java/org/apache/accumulo/core/clientImpl/ClientInfoImpl.java

@@ -29,7 +29,7 @@
 import java.nio.file.Paths;
 import java.util.Optional;
 import java.util.Properties;
-import java.util.function.Function;
+import java.util.function.BiFunction;
 import java.util.function.Supplier;
 
 import org.apache.accumulo.core.client.security.tokens.AuthenticationToken;
@@ -52,18 +52,19 @@ public class ClientInfoImpl implements ClientInfo {
   private final Supplier<AuthenticationToken> tokenSupplier;
   private final Supplier<Configuration> hadoopConf;
   private final Supplier<InstanceId> instanceId;
-  private final Function<String,ZooSession> zooSessionForName;
+  private final BiFunction<String,String,ZooSession> zooSessionForName;
 
   public ClientInfoImpl(Properties properties, Optional<AuthenticationToken> tokenOpt) {
     this.properties = requireNonNull(properties);
     // convert the optional to a supplier to delay retrieval from the properties unless needed
     this.tokenSupplier = requireNonNull(tokenOpt).map(Suppliers::ofInstance)
         .orElse(memoize(() -> ClientProperty.getAuthenticationToken(properties)));
     this.hadoopConf = memoize(Configuration::new);
-    this.zooSessionForName =
-        name -> new ZooSession(name, getZooKeepers(), getZooKeepersSessionTimeOut(), null);
+    this.zooSessionForName = (name, rootPath) -> new ZooSession(name, getZooKeepers() + rootPath,
+        getZooKeepersSessionTimeOut(), null);
     this.instanceId = memoize(() -> {
-      try (var zk = getZooKeeperSupplier(getClass().getSimpleName() + ".getInstanceName()").get()) {
+      try (var zk =
+          getZooKeeperSupplier(getClass().getSimpleName() + ".getInstanceId()", "").get()) {
         return ZooUtil.getInstanceId(zk, getInstanceName());
       }
     });
@@ -80,8 +81,8 @@ public InstanceId getInstanceId() {
   }
 
   @Override
-  public Supplier<ZooSession> getZooKeeperSupplier(String clientName) {
-    return () -> zooSessionForName.apply(clientName);
+  public Supplier<ZooSession> getZooKeeperSupplier(String clientName, String rootPath) {
+    return () -> zooSessionForName.apply(requireNonNull(clientName), requireNonNull(rootPath));
   }
 
   @Override

server/base/src/main/java/org/apache/accumulo/server/ServerInfo.java

@@ -24,6 +24,7 @@
 import java.io.IOException;
 import java.io.UncheckedIOException;
 import java.util.Properties;
+import java.util.function.BiFunction;
 import java.util.function.Function;
 import java.util.function.Supplier;
 import java.util.function.ToIntFunction;
@@ -57,7 +58,8 @@ public class ServerInfo implements ClientInfo {
   static ServerInfo fromServerConfig(SiteConfiguration siteConfig) {
     final Function<ServerInfo,String> instanceNameFromZk = si -> {
       try (var zk =
-          si.getZooKeeperSupplier(ServerInfo.class.getSimpleName() + ".getInstanceId()").get()) {
+          si.getZooKeeperSupplier(ServerInfo.class.getSimpleName() + ".getInstanceName()", "")
+              .get()) {
         return ZooUtil.getInstanceName(zk, si.getInstanceId());
       }
     };
@@ -109,7 +111,7 @@ static ServerInfo forTesting(SiteConfiguration siteConfig, String instanceName,
   private final Supplier<InstanceId> instanceId;
   private final Supplier<String> instanceName;
   private final Supplier<Credentials> credentials;
-  private final Function<String,ZooSession> zooSessionForName;
+  private final BiFunction<String,String,ZooSession> zooSessionForName;
 
   // set up everything to be lazily loaded with memoized suppliers, so if nothing is used, the cost
   // is low; to support different scenarios, plug in the functionality to retrieve certain items
@@ -139,7 +141,7 @@ private ServerInfo(SiteConfiguration siteConfig, Function<ServerInfo,String> zkH
     this.credentials =
         memoize(() -> SystemCredentials.get(getInstanceId(), getSiteConfiguration()));
 
-    this.zooSessionForName = name -> new ZooSession(name, getZooKeepers(),
+    this.zooSessionForName = (name, rootPath) -> new ZooSession(name, getZooKeepers() + rootPath,
         getZooKeepersSessionTimeOut(), getSiteConfiguration().get(Property.INSTANCE_SECRET));
 
     // from here on, set up the suppliers based on what was passed in, to support different cases
@@ -163,8 +165,8 @@ public InstanceId getInstanceId() {
   }
 
   @Override
-  public Supplier<ZooSession> getZooKeeperSupplier(String clientName) {
-    return () -> zooSessionForName.apply(clientName);
+  public Supplier<ZooSession> getZooKeeperSupplier(String clientName, String rootPath) {
+    return () -> zooSessionForName.apply(requireNonNull(clientName), requireNonNull(rootPath));
   }
 
   @Override