zookeeper chroot fix (#1430)

* added root and identity section to zookeeper configuration [#CLICKHOUSE-3031]

* added root and identity section to zookeeper configuration [#CLICKHOUSE-3031]

* moved root section in zookeeper configuration [#CLICKHOUSE-3031]

* fixed root section in zookeeper configuration [#CLICKHOUSE-3031]

* added tests [#CLICKHOUSE-3031]

* replaced tabs to spaces in config files [#CLICKHOUSE-3031]

* fix build [#CLICKHOUSE-3031]

* added chech that root starts with '/' in zookeeper config file [#CLICKHOUSE-3031]

* added comments [#CLICKHOUSE-3031]

* Check if zookeeper chroot exists before start. Remove tailing slash form chroot. [#CLICKHOUSE-3400]

* added starting '/' to zookeeper path in ReplicatedMergeTree

dbms/src/Common/ZooKeeper/ZooKeeper.cpp

@@ -71,7 +71,8 @@ void ZooKeeper::processCallback(zhandle_t * zh, int type, int state, const char
         destroyContext(context);
 }
 
-void ZooKeeper::init(const std::string & hosts_, const std::string & identity_, int32_t session_timeout_ms_)
+void ZooKeeper::init(const std::string & hosts_, const std::string & identity_,
+                     int32_t session_timeout_ms_, bool check_root_exists)
 {
     log = &Logger::get("ZooKeeper");
     zoo_set_debug_level(ZOO_LOG_LEVEL_ERROR);
@@ -87,7 +88,7 @@ void ZooKeeper::init(const std::string & hosts_, const std::string & identity_,
 
     if (!identity.empty())
     {
-        auto code = zoo_add_auth(impl, "digest", identity.c_str(), static_cast<int>(identity.size()), 0, 0);
+        auto code = zoo_add_auth(impl, "digest", identity.c_str(), static_cast<int>(identity.size()), nullptr, nullptr);
         if (code != ZOK)
             throw KeeperException("Zookeeper authentication failed. Hosts are  " + hosts, code);
 
@@ -97,11 +98,15 @@ void ZooKeeper::init(const std::string & hosts_, const std::string & identity_,
         default_acl = &ZOO_OPEN_ACL_UNSAFE;
 
     LOG_TRACE(log, "initialized, hosts: " << hosts);
+
+    if (check_root_exists && !exists("/"))
+        throw KeeperException("Zookeeper root doesn't exist. You should create root node before start.");
 }
 
-ZooKeeper::ZooKeeper(const std::string & hosts, const std::string & identity, int32_t session_timeout_ms)
+ZooKeeper::ZooKeeper(const std::string & hosts, const std::string & identity,
+                     int32_t session_timeout_ms, bool check_root_exists)
 {
-    init(hosts, identity, session_timeout_ms);
+    init(hosts, identity, session_timeout_ms, check_root_exists);
 }
 
 struct ZooKeeperArgs
@@ -115,6 +120,7 @@ struct ZooKeeperArgs
         std::string root;
 
         session_timeout_ms = DEFAULT_SESSION_TIMEOUT;
+        has_chroot = false;
         for (const auto & key : keys)
         {
             if (startsWith(key, "node"))
@@ -154,19 +160,24 @@ struct ZooKeeperArgs
         {
             if (root.front() != '/')
                 throw KeeperException(std::string("Root path in config file should start with '/', but got ") + root);
+            if (root.back() == '/')
+                root.pop_back();
+
             hosts += root;
+            has_chroot = true;
         }
     }
 
     std::string hosts;
     std::string identity;
     int session_timeout_ms;
+    bool has_chroot;
 };
 
 ZooKeeper::ZooKeeper(const Poco::Util::AbstractConfiguration & config, const std::string & config_name)
 {
     ZooKeeperArgs args(config, config_name);
-    init(args.hosts, args.identity, args.session_timeout_ms);
+    init(args.hosts, args.identity, args.session_timeout_ms, args.has_chroot);
 }
 
 WatchCallback ZooKeeper::callbackForEvent(const EventPtr & event)

dbms/src/Common/ZooKeeper/ZooKeeper.h

@@ -54,7 +54,8 @@ class ZooKeeper
 public:
     using Ptr = std::shared_ptr<ZooKeeper>;
 
-    ZooKeeper(const std::string & hosts, const std::string & identity = "", int32_t session_timeout_ms = DEFAULT_SESSION_TIMEOUT);
+    ZooKeeper(const std::string & hosts, const std::string & identity = "",
+              int32_t session_timeout_ms = DEFAULT_SESSION_TIMEOUT, bool check_root_exists = false);
 
     /** Config of the form:
         <zookeeper>
@@ -357,7 +358,8 @@ private:
     friend struct WatchContext;
     friend class EphemeralNodeHolder;
 
-    void init(const std::string & hosts, const std::string & identity, int32_t session_timeout_ms);
+    void init(const std::string & hosts, const std::string & identity,
+              int32_t session_timeout_ms, bool check_root_exists);
     void removeChildrenRecursive(const std::string & path);
     void tryRemoveChildrenRecursive(const std::string & path);
 

dbms/src/Storages/StorageReplicatedMergeTree.cpp

@@ -211,6 +211,9 @@ StorageReplicatedMergeTree::StorageReplicatedMergeTree(
 {
     if (!zookeeper_path.empty() && zookeeper_path.back() == '/')
         zookeeper_path.resize(zookeeper_path.size() - 1);
+    /// If zookeeper chroot prefix is used, path should starts with '/', because chroot concatenates without it.
+    if (!zookeeper_path.empty() && zookeeper_path.front() != '/')
+        zookeeper_path = "/" + zookeeper_path;
     replica_path = zookeeper_path + "/replicas/" + replica_name;
 
     bool skip_sanity_checks = false;