Fix error with IPv6 in host param

src/Client/ClientBase.h

@@ -246,22 +246,11 @@ class ClientBase : public Poco::Util::Application, public IHints<2, ClientBase>
             String host_with_port;
             in >> host_with_port;
             DB::DNSResolver & resolver = DB::DNSResolver::instance();
-            try
-            {
-                Poco::Net::SocketAddress address = resolver.resolveAddress(host_with_port);
-                hostPort.host = address.host().toString();
-                hostPort.port = address.port();
-            }
-            catch (const Exception & e)
-            {
-                if (e.message() == "Missing port number")
-                {
-                    hostPort.host = resolver.resolveHost(host_with_port).toString();
-                    hostPort.port = std::nullopt;
-                    return in;
-                }
-                throw;
-            }
+            std::pair<Poco::Net::IPAddress, std::optional<UInt16>>
+                host_and_port = resolver.resolveHostOrAddress(host_with_port);
+            hostPort.host = host_and_port.first.toString();
+            hostPort.port = host_and_port.second;
+
             return in;
         }
     };

src/Common/DNSResolver.cpp

@@ -202,6 +202,45 @@ Poco::Net::SocketAddress DNSResolver::resolveAddress(const std::string & host, U
     return  Poco::Net::SocketAddress(impl->cache_host(host).front(), port);
 }
 
+std::pair<Poco::Net::IPAddress, std::optional<UInt16>> DNSResolver::resolveHostOrAddress(const std::string & host_and_port)
+{
+    Poco::Net::IPAddress ip;
+
+    size_t number_of_colons = std::count(host_and_port.begin(), host_and_port.end(), ':');
+    if (number_of_colons > 1)
+    {
+        /// IPv6 host
+        if (host_and_port.starts_with('['))
+        {
+            size_t close_bracket_pos = host_and_port.find(']');
+            assert(close_bracket_pos != std::string::npos);
+            ip = resolveHost(host_and_port.substr(0, close_bracket_pos));
+
+            if (close_bracket_pos == host_and_port.size() - 1)
+                return {ip, std::nullopt};
+            if (host_and_port[close_bracket_pos + 1] != ':')
+                throw Exception("Missing delimiter between host and port", ErrorCodes::BAD_ARGUMENTS);
+
+            unsigned int port;
+            if (!Poco::NumberParser::tryParseUnsigned(host_and_port.substr(close_bracket_pos + 2), port))
+                throw Exception("Port must be numeric", ErrorCodes::BAD_ARGUMENTS);
+            if (port > 0xFFFF)
+                throw Exception("Port must be less 0xFFFF", ErrorCodes::BAD_ARGUMENTS);
+            return {ip, port};
+        }
+        return {resolveHost(host_and_port), std::nullopt};
+    }
+    else if (number_of_colons == 1)
+    {
+        /// IPv4 host with port
+        Poco::Net::SocketAddress socket = resolveAddress(host_and_port);
+        return {socket.host(), socket.port()};
+    }
+
+    /// IPv4 host
+    return {resolveHost(host_and_port), std::nullopt};
+}
+
 String DNSResolver::reverseResolve(const Poco::Net::IPAddress & address)
 {
     if (impl->disable_cache)

src/Common/DNSResolver.h

@@ -34,6 +34,10 @@ class DNSResolver : private boost::noncopyable
 
     Poco::Net::SocketAddress resolveAddress(const std::string & host, UInt16 port);
 
+    /// Accepts host names like 'example.com'/'example.com:port' or '127.0.0.1'/'127.0.0.1:port' or '::1'/'[::1]:port'
+    /// and resolves its IP and port, if port is set
+    std::pair<Poco::Net::IPAddress, std::optional<UInt16>> resolveHostOrAddress(const std::string & host_and_port);
+
     /// Accepts host IP and resolves its host name
     String reverseResolve(const Poco::Net::IPAddress & address);
 

tests/queries/0_stateless/02100_multiple_hosts_command_line_set.reference

@@ -6,3 +6,6 @@
 1
 1
 1
+1
+1
+1

tests/queries/0_stateless/02100_multiple_hosts_command_line_set.sh

@@ -33,3 +33,19 @@ error="$(${CLICKHOUSE_CLIENT} --host "${CLICKHOUSE_HOST}" --port "${not_alive_po
 ${CLICKHOUSE_CLIENT} --host "${CLICKHOUSE_HOST}:${not_alive_port}" "${CLICKHOUSE_HOST}" --query "SELECT 1";
 ${CLICKHOUSE_CLIENT} --host "${CLICKHOUSE_HOST}:${CLICKHOUSE_PORT_TCP}" --port "${not_alive_port}" --query "SELECT 1";
 
+ipv6_host_without_brackets="2001:3984:3989::1:1000"
+exception_msg="Code: 210. DB::NetException: Connection refused (${ipv6_host_without_brackets}). (NETWORK_ERROR)
+"
+error="$(${CLICKHOUSE_CLIENT} --host "${ipv6_host_without_brackets}" --query "SELECT 1" 2>&1 > /dev/null)"
+[ "${error}" == "${exception_msg}" ]; echo "$?"
+
+ipv6_host_with_brackets="[2001:3984:3989::1:1000]"
+exception_msg="Code: 210. DB::NetException: Connection refused (${ipv6_host_with_brackets}). (NETWORK_ERROR)
+"
+error="$(${CLICKHOUSE_CLIENT} --host "${ipv6_host_with_brackets}" --query "SELECT 1" 2>&1 > /dev/null)"
+[ "${error}" == "${exception_msg}" ]; echo "$?"
+
+exception_msg="Code: 210. DB::NetException: Connection refused (${ipv6_host_with_brackets}:${not_alive_port}). (NETWORK_ERROR)
+"
+error="$(${CLICKHOUSE_CLIENT} --host "${ipv6_host_with_brackets}:${not_alive_port}" --query "SELECT 1" 2>&1 > /dev/null)"
+[ "${error}" == "${exception_msg}" ]; echo "$?"