# 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.

import json
import os.path
import re
import signal
import time

from ducktape.services.service import Service
from ducktape.utils.util import wait_until
from ducktape.cluster.remoteaccount import RemoteCommandError

from .config import KafkaConfig
from kafkatest.directory_layout.kafka_path import KafkaPathResolverMixin
from kafkatest.services.kafka import config_property
from kafkatest.services.monitor.jmx import JmxMixin
from kafkatest.services.security.minikdc import MiniKdc
from kafkatest.services.security.listener_security_config import ListenerSecurityConfig
from kafkatest.services.security.security_config import SecurityConfig
from kafkatest.version import DEV_BRANCH
from kafkatest.services.kafka.util import fix_opts_for_new_jvm


class KafkaListener:

    def __init__(self, name, port_number, security_protocol, open=False):
        self.name = name
        self.port_number = port_number
        self.security_protocol = security_protocol
        self.open = open

    def listener(self):
        return "%s://:%s" % (self.name, str(self.port_number))

    def advertised_listener(self, node):
        return "%s://%s:%s" % (self.name, node.account.hostname, str(self.port_number))

    def listener_security_protocol(self):
        return "%s:%s" % (self.name, self.security_protocol)

class KafkaService(KafkaPathResolverMixin, JmxMixin, Service):
    PERSISTENT_ROOT = "/mnt/kafka"
    STDOUT_STDERR_CAPTURE = os.path.join(PERSISTENT_ROOT, "server-start-stdout-stderr.log")
    LOG4J_CONFIG = os.path.join(PERSISTENT_ROOT, "kafka-log4j.properties")
    # Logs such as controller.log, server.log, etc all go here
    OPERATIONAL_LOG_DIR = os.path.join(PERSISTENT_ROOT, "kafka-operational-logs")
    OPERATIONAL_LOG_INFO_DIR = os.path.join(OPERATIONAL_LOG_DIR, "info")
    OPERATIONAL_LOG_DEBUG_DIR = os.path.join(OPERATIONAL_LOG_DIR, "debug")
    # Kafka log segments etc go here
    DATA_LOG_DIR_PREFIX = os.path.join(PERSISTENT_ROOT, "kafka-data-logs")
    DATA_LOG_DIR_1 = "%s-1" % (DATA_LOG_DIR_PREFIX)
    DATA_LOG_DIR_2 = "%s-2" % (DATA_LOG_DIR_PREFIX)
    CONFIG_FILE = os.path.join(PERSISTENT_ROOT, "kafka.properties")
    # Kafka Authorizer
    ACL_AUTHORIZER = "kafka.security.authorizer.AclAuthorizer"
    # Old Kafka Authorizer. This is deprecated but still supported.
    SIMPLE_AUTHORIZER = "kafka.security.auth.SimpleAclAuthorizer"
    HEAP_DUMP_FILE = os.path.join(PERSISTENT_ROOT, "kafka_heap_dump.bin")
    INTERBROKER_LISTENER_NAME = 'INTERNAL'
    JAAS_CONF_PROPERTY = "java.security.auth.login.config=/mnt/security/jaas.conf"
    ADMIN_CLIENT_AS_BROKER_JAAS_CONF_PROPERTY = "java.security.auth.login.config=/mnt/security/admin_client_as_broker_jaas.conf"
    KRB5_CONF = "java.security.krb5.conf=/mnt/security/krb5.conf"

    logs = {
        "kafka_server_start_stdout_stderr": {
            "path": STDOUT_STDERR_CAPTURE,
            "collect_default": True},
        "kafka_operational_logs_info": {
            "path": OPERATIONAL_LOG_INFO_DIR,
            "collect_default": True},
        "kafka_operational_logs_debug": {
            "path": OPERATIONAL_LOG_DEBUG_DIR,
            "collect_default": False},
        "kafka_data_1": {
            "path": DATA_LOG_DIR_1,
            "collect_default": False},
        "kafka_data_2": {
            "path": DATA_LOG_DIR_2,
            "collect_default": False},
        "kafka_heap_dump_file": {
            "path": HEAP_DUMP_FILE,
            "collect_default": True}
    }

    def __init__(self, context, num_nodes, zk, security_protocol=SecurityConfig.PLAINTEXT,
                 interbroker_security_protocol=SecurityConfig.PLAINTEXT,
                 client_sasl_mechanism=SecurityConfig.SASL_MECHANISM_GSSAPI, interbroker_sasl_mechanism=SecurityConfig.SASL_MECHANISM_GSSAPI,
                 authorizer_class_name=None, topics=None, version=DEV_BRANCH, jmx_object_names=None,
                 jmx_attributes=None, zk_connect_timeout=18000, zk_session_timeout=18000, server_prop_overides=None, zk_chroot=None,
                 zk_client_secure=False,
                 listener_security_config=ListenerSecurityConfig(), per_node_server_prop_overrides=None,
                 extra_kafka_opts="", tls_version=None):
        """
        :param context: test context
        :param ZookeeperService zk:
        :param dict topics: which topics to create automatically
        :param str security_protocol: security protocol for clients to use
        :param str tls_version: version of the TLS protocol.
        :param str interbroker_security_protocol: security protocol to use for broker-to-broker communication
        :param str client_sasl_mechanism: sasl mechanism for clients to use
        :param str interbroker_sasl_mechanism: sasl mechanism to use for broker-to-broker communication
        :param str authorizer_class_name: which authorizer class to use
        :param str version: which kafka version to use. Defaults to "dev" branch
        :param jmx_object_names:
        :param jmx_attributes:
        :param int zk_connect_timeout:
        :param int zk_session_timeout:
        :param dict server_prop_overides: overrides for kafka.properties file
        :param zk_chroot:
        :param bool zk_client_secure: connect to Zookeeper over secure client port (TLS) when True
        :param ListenerSecurityConfig listener_security_config: listener config to use
        :param dict per_node_server_prop_overrides:
        :param str extra_kafka_opts: jvm args to add to KAFKA_OPTS variable
        """
        Service.__init__(self, context, num_nodes)
        JmxMixin.__init__(self, num_nodes=num_nodes, jmx_object_names=jmx_object_names, jmx_attributes=(jmx_attributes or []),
                          root=KafkaService.PERSISTENT_ROOT)

        self.zk = zk

        self.security_protocol = security_protocol
        self.tls_version = tls_version
        self.client_sasl_mechanism = client_sasl_mechanism
        self.topics = topics
        self.minikdc = None
        self.authorizer_class_name = authorizer_class_name
        self.zk_set_acl = False
        if server_prop_overides is None:
            self.server_prop_overides = []
        else:
            self.server_prop_overides = server_prop_overides
        if per_node_server_prop_overrides is None:
            self.per_node_server_prop_overrides = {}
        else:
            self.per_node_server_prop_overrides = per_node_server_prop_overrides
        self.log_level = "DEBUG"
        self.zk_chroot = zk_chroot
        self.zk_client_secure = zk_client_secure
        self.listener_security_config = listener_security_config
        self.extra_kafka_opts = extra_kafka_opts

        #
        # In a heavily loaded and not very fast machine, it is
        # sometimes necessary to give more time for the zk client
        # to have its session established, especially if the client
        # is authenticating and waiting for the SaslAuthenticated
        # in addition to the SyncConnected event.
        #
        # The default value for zookeeper.connect.timeout.ms is
        # 2 seconds and here we increase it to 5 seconds, but
        # it can be overridden by setting the corresponding parameter
        # for this constructor.
        self.zk_connect_timeout = zk_connect_timeout

        # Also allow the session timeout to be provided explicitly,
        # primarily so that test cases can depend on it when waiting
        # e.g. brokers to deregister after a hard kill.
        self.zk_session_timeout = zk_session_timeout

        self.port_mappings = {
            'PLAINTEXT': KafkaListener('PLAINTEXT', 9092, 'PLAINTEXT', False),
            'SSL': KafkaListener('SSL', 9093, 'SSL', False),
            'SASL_PLAINTEXT': KafkaListener('SASL_PLAINTEXT', 9094, 'SASL_PLAINTEXT', False),
            'SASL_SSL': KafkaListener('SASL_SSL', 9095, 'SASL_SSL', False),
            KafkaService.INTERBROKER_LISTENER_NAME:
                KafkaListener(KafkaService.INTERBROKER_LISTENER_NAME, 9099, None, False)
        }

        self.interbroker_listener = None
        self.setup_interbroker_listener(interbroker_security_protocol, self.listener_security_config.use_separate_interbroker_listener)
        self.interbroker_sasl_mechanism = interbroker_sasl_mechanism
        self._security_config = None

        for node in self.nodes:
            node.version = version
            node.config = KafkaConfig(**{
                config_property.BROKER_ID: self.idx(node),
                config_property.ZOOKEEPER_CONNECTION_TIMEOUT_MS: zk_connect_timeout,
                config_property.ZOOKEEPER_SESSION_TIMEOUT_MS: zk_session_timeout
            })

    def set_version(self, version):
        for node in self.nodes:
            node.version = version

    @property
    def interbroker_security_protocol(self):
        return self.interbroker_listener.security_protocol

    # this is required for backwards compatibility - there are a lot of tests that set this property explicitly
    # meaning 'use one of the existing listeners that match given security protocol, do not use custom listener'
    @interbroker_security_protocol.setter
    def interbroker_security_protocol(self, security_protocol):
        self.setup_interbroker_listener(security_protocol, use_separate_listener=False)

    def setup_interbroker_listener(self, security_protocol, use_separate_listener=False):
        self.listener_security_config.use_separate_interbroker_listener = use_separate_listener

        if self.listener_security_config.use_separate_interbroker_listener:
            # do not close existing port here since it is not used exclusively for interbroker communication
            self.interbroker_listener = self.port_mappings[KafkaService.INTERBROKER_LISTENER_NAME]
            self.interbroker_listener.security_protocol = security_protocol
        else:
            # close dedicated interbroker port, so it's not dangling in 'listeners' and 'advertised.listeners'
            self.close_port(KafkaService.INTERBROKER_LISTENER_NAME)
            self.interbroker_listener = self.port_mappings[security_protocol]

    @property
    def security_config(self):
        if not self._security_config:
            self._security_config = SecurityConfig(self.context, self.security_protocol, self.interbroker_listener.security_protocol,
                                    zk_sasl=self.zk.zk_sasl, zk_tls=self.zk_client_secure,
                                    client_sasl_mechanism=self.client_sasl_mechanism,
                                    interbroker_sasl_mechanism=self.interbroker_sasl_mechanism,
                                    listener_security_config=self.listener_security_config,
                                    tls_version=self.tls_version)
        for port in self.port_mappings.values():
            if port.open:
                self._security_config.enable_security_protocol(port.security_protocol)
        if self.zk.zk_sasl:
            self._security_config.enable_sasl()
            self._security_config.zk_sasl = self.zk.zk_sasl
        if self.zk_client_secure:
            self._security_config.enable_ssl()
            self._security_config.zk_tls = self.zk_client_secure
        return self._security_config

    def open_port(self, listener_name):
        self.port_mappings[listener_name].open = True

    def close_port(self, listener_name):
        self.port_mappings[listener_name].open = False

    def start_minikdc_if_necessary(self, add_principals=""):
        if self.security_config.has_sasl:
            if self.minikdc is None:
                self.minikdc = MiniKdc(self.context, self.nodes, extra_principals = add_principals)
                self.minikdc.start()
        else:
            self.minikdc = None

    def alive(self, node):
        return len(self.pids(node)) > 0

    def start(self, add_principals=""):
        if self.zk_client_secure and not self.zk.zk_client_secure_port:
            raise Exception("Unable to start Kafka: TLS to Zookeeper requested but Zookeeper secure port not enabled")
        self.open_port(self.security_protocol)
        self.interbroker_listener.open = True

        self.start_minikdc_if_necessary(add_principals)
        self._ensure_zk_chroot()

        Service.start(self)

        self.logger.info("Waiting for brokers to register at ZK")

        retries = 30
        expected_broker_ids = set(self.nodes)
        wait_until(lambda: {node for node in self.nodes if self.is_registered(node)} == expected_broker_ids, 30, 1)

        if retries == 0:
            raise RuntimeError("Kafka servers didn't register at ZK within 30 seconds")

        # Create topics if necessary
        if self.topics is not None:
            for topic, topic_cfg in self.topics.items():
                if topic_cfg is None:
                    topic_cfg = {}

                topic_cfg["topic"] = topic
                self.create_topic(topic_cfg)

    def _ensure_zk_chroot(self):
        self.logger.info("Ensuring zk_chroot %s exists", self.zk_chroot)
        if self.zk_chroot:
            if not self.zk_chroot.startswith('/'):
                raise Exception("Zookeeper chroot must start with '/' but found " + self.zk_chroot)

            parts = self.zk_chroot.split('/')[1:]
            for i in range(len(parts)):
                self.zk.create('/' + '/'.join(parts[:i+1]))

    def set_protocol_and_port(self, node):
        listeners = []
        advertised_listeners = []
        protocol_map = []

        for port in self.port_mappings.values():
            if port.open:
                listeners.append(port.listener())
                advertised_listeners.append(port.advertised_listener(node))
                protocol_map.append(port.listener_security_protocol())

        self.listeners = ','.join(listeners)
        self.advertised_listeners = ','.join(advertised_listeners)
        self.listener_security_protocol_map = ','.join(protocol_map)
        self.interbroker_bootstrap_servers = self.__bootstrap_servers(self.interbroker_listener, True)

    def prop_file(self, node):
        self.set_protocol_and_port(node)

        #load template configs as dictionary
        config_template = self.render('kafka.properties', node=node, broker_id=self.idx(node),
                                      security_config=self.security_config, num_nodes=self.num_nodes,
                                      listener_security_config=self.listener_security_config)

        configs = dict( l.rstrip().split('=', 1) for l in config_template.split('\n')
                        if not l.startswith("#") and "=" in l )

        #load specific test override configs
        override_configs = KafkaConfig(**node.config)
        override_configs[config_property.ADVERTISED_HOSTNAME] = node.account.hostname
        override_configs[config_property.ZOOKEEPER_CONNECT] = self.zk_connect_setting()
        if self.zk_client_secure:
            override_configs[config_property.ZOOKEEPER_SSL_CLIENT_ENABLE] = 'true'
            override_configs[config_property.ZOOKEEPER_CLIENT_CNXN_SOCKET] = 'org.apache.zookeeper.ClientCnxnSocketNetty'
        else:
            override_configs[config_property.ZOOKEEPER_SSL_CLIENT_ENABLE] = 'false'

        for prop in self.server_prop_overides:
            override_configs[prop[0]] = prop[1]

        for prop in self.per_node_server_prop_overrides.get(self.idx(node), []):
            override_configs[prop[0]] = prop[1]

        #update template configs with test override configs
        configs.update(override_configs)

        prop_file = self.render_configs(configs)
        return prop_file

    def render_configs(self, configs):
        """Render self as a series of lines key=val\n, and do so in a consistent order. """
        keys = [k for k in configs.keys()]
        keys.sort()

        s = ""
        for k in keys:
            s += "%s=%s\n" % (k, str(configs[k]))
        return s

    def start_cmd(self, node):
        cmd = "export JMX_PORT=%d; " % self.jmx_port
        cmd += "export KAFKA_LOG4J_OPTS=\"-Dlog4j.configuration=file:%s\"; " % self.LOG4J_CONFIG
        heap_kafka_opts = "-XX:+HeapDumpOnOutOfMemoryError -XX:HeapDumpPath=%s" % \
                          self.logs["kafka_heap_dump_file"]["path"]
        security_kafka_opts = self.security_config.kafka_opts.strip('\"')

        cmd += fix_opts_for_new_jvm(node)
        cmd += "export KAFKA_OPTS=\"%s %s %s\"; " % (heap_kafka_opts, security_kafka_opts, self.extra_kafka_opts)
        cmd += "%s %s 1>> %s 2>> %s &" % \
               (self.path.script("kafka-server-start.sh", node),
                KafkaService.CONFIG_FILE,
                KafkaService.STDOUT_STDERR_CAPTURE,
                KafkaService.STDOUT_STDERR_CAPTURE)
        return cmd

    def start_node(self, node, timeout_sec=60):
        node.account.mkdirs(KafkaService.PERSISTENT_ROOT)

        self.security_config.setup_node(node)
        self.maybe_setup_broker_scram_credentials(node)

        prop_file = self.prop_file(node)
        self.logger.info("kafka.properties:")
        self.logger.info(prop_file)
        node.account.create_file(KafkaService.CONFIG_FILE, prop_file)
        node.account.create_file(self.LOG4J_CONFIG, self.render('log4j.properties', log_dir=KafkaService.OPERATIONAL_LOG_DIR))

        cmd = self.start_cmd(node)
        self.logger.debug("Attempting to start KafkaService on %s with command: %s" % (str(node.account), cmd))
        with node.account.monitor_log(KafkaService.STDOUT_STDERR_CAPTURE) as monitor:
            node.account.ssh(cmd)
            # Kafka 1.0.0 and higher don't have a space between "Kafka" and "Server"
            monitor.wait_until("Kafka\s*Server.*started", timeout_sec=timeout_sec, backoff_sec=.25,
                               err_msg="Kafka server didn't finish startup in %d seconds" % timeout_sec)

        # Credentials for inter-broker communication are created before starting Kafka.
        # Client credentials are created after starting Kafka so that both loading of
        # existing credentials from ZK and dynamic update of credentials in Kafka are tested.
        # We use the admin client and connect as the broker user when creating the client (non-broker) credentials
        # if Kafka supports KIP-554, otherwise we use ZooKeeper.
        self.maybe_setup_client_scram_credentials(node)

        self.start_jmx_tool(self.idx(node), node)
        if len(self.pids(node)) == 0:
            raise Exception("No process ids recorded on node %s" % node.account.hostname)

    def pids(self, node):
        """Return process ids associated with running processes on the given node."""
        try:
            cmd = "jcmd | grep -e %s -e %s | awk '{print $1}'" % (self.java_class_name(), self.deprecated_cp_java_class_name())
            pid_arr = [pid for pid in node.account.ssh_capture(cmd, allow_fail=True, callback=int)]
            return pid_arr
        except (RemoteCommandError, ValueError) as e:
            return []

    def signal_node(self, node, sig=signal.SIGTERM):
        pids = self.pids(node)
        for pid in pids:
            node.account.signal(pid, sig)

    def signal_leader(self, topic, partition=0, sig=signal.SIGTERM):
        leader = self.leader(topic, partition)
        self.signal_node(leader, sig)

    def stop_node(self, node, clean_shutdown=True, timeout_sec=60):
        pids = self.pids(node)
        sig = signal.SIGTERM if clean_shutdown else signal.SIGKILL

        for pid in pids:
            node.account.signal(pid, sig, allow_fail=False)

        try:
            wait_until(lambda: len(self.pids(node)) == 0, timeout_sec=timeout_sec,
                       err_msg="Kafka node failed to stop in %d seconds" % timeout_sec)
        except Exception:
            self.thread_dump(node)
            raise

    def thread_dump(self, node):
        for pid in self.pids(node):
            try:
                node.account.signal(pid, signal.SIGQUIT, allow_fail=True)
            except:
                self.logger.warn("Could not dump threads on node")

    def clean_node(self, node):
        JmxMixin.clean_node(self, node)
        self.security_config.clean_node(node)
        node.account.kill_java_processes(self.java_class_name(),
                                         clean_shutdown=False, allow_fail=True)
        node.account.kill_java_processes(self.deprecated_cp_java_class_name(),
                                         clean_shutdown=False, allow_fail=True)
        node.account.ssh("sudo rm -rf -- %s" % KafkaService.PERSISTENT_ROOT, allow_fail=False)

    def kafka_topics_cmd_with_optional_security_settings(self, node, force_use_zk_connection, kafka_security_protocol = None):
        if force_use_zk_connection:
            bootstrap_server_or_zookeeper = "--zookeeper %s" % (self.zk_connect_setting())
            skip_optional_security_settings = True
        else:
            if kafka_security_protocol is None:
                # it wasn't specified, so use the inter-broker security protocol if it is PLAINTEXT,
                # otherwise use the client security protocol
                if self.interbroker_security_protocol == SecurityConfig.PLAINTEXT:
                    security_protocol_to_use = SecurityConfig.PLAINTEXT
                else:
                    security_protocol_to_use = self.security_protocol
            else:
                security_protocol_to_use = kafka_security_protocol
            bootstrap_server_or_zookeeper = "--bootstrap-server %s" % (self.bootstrap_servers(security_protocol_to_use))
            skip_optional_security_settings = security_protocol_to_use == SecurityConfig.PLAINTEXT
        if skip_optional_security_settings:
            optional_jass_krb_system_props_prefix = ""
            optional_command_config_suffix = ""
        else:
            # we need security configs because aren't going to ZooKeeper and we aren't using PLAINTEXT
            if (security_protocol_to_use == self.interbroker_security_protocol):
                # configure JAAS to provide the broker's credentials
                # since this is an authenticating cluster and we are going to use the inter-broker security protocol
                jaas_conf_prop = KafkaService.ADMIN_CLIENT_AS_BROKER_JAAS_CONF_PROPERTY
                use_inter_broker_mechanism_for_client = True
            else:
                # configure JAAS to provide the typical client credentials
                jaas_conf_prop = KafkaService.JAAS_CONF_PROPERTY
                use_inter_broker_mechanism_for_client = False
            optional_jass_krb_system_props_prefix = "KAFKA_OPTS='-D%s -D%s' " % (jaas_conf_prop, KafkaService.KRB5_CONF)
            optional_command_config_suffix = " --command-config <(echo '%s')" % (self.security_config.client_config(use_inter_broker_mechanism_for_client = use_inter_broker_mechanism_for_client))
        kafka_topic_script = self.path.script("kafka-topics.sh", node)
        return "%s%s %s%s" % \
               (optional_jass_krb_system_props_prefix, kafka_topic_script,
                bootstrap_server_or_zookeeper, optional_command_config_suffix)

    def kafka_configs_cmd_with_optional_security_settings(self, node, force_use_zk_connection, kafka_security_protocol = None):
        if force_use_zk_connection:
            # kafka-configs supports a TLS config file, so include it if there is one
            bootstrap_server_or_zookeeper = "--zookeeper %s %s" % (self.zk_connect_setting(), self.zk.zkTlsConfigFileOption())
            skip_optional_security_settings = True
        else:
            if kafka_security_protocol is None:
                # it wasn't specified, so use the inter-broker security protocol if it is PLAINTEXT,
                # otherwise use the client security protocol
                if self.interbroker_security_protocol == SecurityConfig.PLAINTEXT:
                    security_protocol_to_use = SecurityConfig.PLAINTEXT
                else:
                    security_protocol_to_use = self.security_protocol
            else:
                security_protocol_to_use = kafka_security_protocol
            bootstrap_server_or_zookeeper = "--bootstrap-server %s" % (self.bootstrap_servers(security_protocol_to_use))
            skip_optional_security_settings = security_protocol_to_use == SecurityConfig.PLAINTEXT
        if skip_optional_security_settings:
            optional_jass_krb_system_props_prefix = ""
            optional_command_config_suffix = ""
        else:
            # we need security configs because aren't going to ZooKeeper and we aren't using PLAINTEXT
            if (security_protocol_to_use == self.interbroker_security_protocol):
                # configure JAAS to provide the broker's credentials
                # since this is an authenticating cluster and we are going to use the inter-broker security protocol
                jaas_conf_prop = KafkaService.ADMIN_CLIENT_AS_BROKER_JAAS_CONF_PROPERTY
                use_inter_broker_mechanism_for_client = True
            else:
                # configure JAAS to provide the typical client credentials
                jaas_conf_prop = KafkaService.JAAS_CONF_PROPERTY
                use_inter_broker_mechanism_for_client = False
            optional_jass_krb_system_props_prefix = "KAFKA_OPTS='-D%s -D%s' " % (jaas_conf_prop, KafkaService.KRB5_CONF)
            optional_command_config_suffix = " --command-config <(echo '%s')" % (self.security_config.client_config(use_inter_broker_mechanism_for_client = use_inter_broker_mechanism_for_client))
        kafka_config_script = self.path.script("kafka-configs.sh", node)
        return "%s%s %s%s" % \
               (optional_jass_krb_system_props_prefix, kafka_config_script,
                bootstrap_server_or_zookeeper, optional_command_config_suffix)

    def maybe_setup_broker_scram_credentials(self, node):
        security_config = self.security_config
        # we only need to create broker credentials when the broker mechanism is SASL/SCRAM
        if security_config.is_sasl(self.interbroker_security_protocol) and security_config.is_sasl_scram(self.interbroker_sasl_mechanism):
            force_use_zk_connection = True # we are bootstrapping these credentials before Kafka is started
            cmd = fix_opts_for_new_jvm(node)
            cmd += "%(kafka_configs_cmd)s --entity-name %(user)s --entity-type users --alter --add-config %(mechanism)s=[password=%(password)s]" % {
                'kafka_configs_cmd': self.kafka_configs_cmd_with_optional_security_settings(node, force_use_zk_connection),
                'user': SecurityConfig.SCRAM_BROKER_USER,
                'mechanism': self.interbroker_sasl_mechanism,
                'password': SecurityConfig.SCRAM_BROKER_PASSWORD
            }
            node.account.ssh(cmd)

    def maybe_setup_client_scram_credentials(self, node):
        security_config = self.security_config
        # we only need to create client credentials when the client mechanism is SASL/SCRAM
        if security_config.is_sasl(self.security_protocol) and security_config.is_sasl_scram(self.client_sasl_mechanism):
            force_use_zk_connection = not self.all_nodes_configs_command_uses_bootstrap_server_scram()
            # ignored if forcing the use of Zookeeper, but we need a value to send, so calculate it anyway
            if self.interbroker_security_protocol == SecurityConfig.PLAINTEXT:
                kafka_security_protocol = self.interbroker_security_protocol
            else:
                kafka_security_protocol = self.security_protocol
            cmd = fix_opts_for_new_jvm(node)
            cmd += "%(kafka_configs_cmd)s --entity-name %(user)s --entity-type users --alter --add-config %(mechanism)s=[password=%(password)s]" % {
                'kafka_configs_cmd': self.kafka_configs_cmd_with_optional_security_settings(node, force_use_zk_connection, kafka_security_protocol),
                'user': SecurityConfig.SCRAM_CLIENT_USER,
                'mechanism': self.client_sasl_mechanism,
                'password': SecurityConfig.SCRAM_CLIENT_PASSWORD
            }
            node.account.ssh(cmd)

    def all_nodes_topic_command_supports_bootstrap_server(self):
        for node in self.nodes:
            if not node.version.topic_command_supports_bootstrap_server():
                return False
        return True

    def all_nodes_topic_command_supports_if_not_exists_with_bootstrap_server(self):
        for node in self.nodes:
            if not node.version.topic_command_supports_if_not_exists_with_bootstrap_server():
                return False
        return True

    def all_nodes_configs_command_uses_bootstrap_server(self):
        for node in self.nodes:
            if not node.version.kafka_configs_command_uses_bootstrap_server():
                return False
        return True

    def all_nodes_configs_command_uses_bootstrap_server_scram(self):
        for node in self.nodes:
            if not node.version.kafka_configs_command_uses_bootstrap_server_scram():
                return False
        return True

    def all_nodes_acl_command_supports_bootstrap_server(self):
        for node in self.nodes:
            if not node.version.acl_command_supports_bootstrap_server():
                return False
        return True

    def all_nodes_reassign_partitions_command_supports_bootstrap_server(self):
        for node in self.nodes:
            if not node.version.reassign_partitions_command_supports_bootstrap_server():
                return False
        return True

    def create_topic(self, topic_cfg, node=None):
        """Run the admin tool create topic command.
        Specifying node is optional, and may be done if for different kafka nodes have different versions,
        and we care where command gets run.

        If the node is not specified, run the command from self.nodes[0]
        """
        if node is None:
            node = self.nodes[0]
        self.logger.info("Creating topic %s with settings %s",
                         topic_cfg["topic"], topic_cfg)

        force_use_zk_connection = not self.all_nodes_topic_command_supports_bootstrap_server() or\
                            (topic_cfg.get('if-not-exists', False) and not self.all_nodes_topic_command_supports_if_not_exists_with_bootstrap_server())

        cmd = fix_opts_for_new_jvm(node)
        cmd += "%(kafka_topics_cmd)s --create --topic %(topic)s " % {
            'kafka_topics_cmd': self.kafka_topics_cmd_with_optional_security_settings(node, force_use_zk_connection),
            'topic': topic_cfg.get("topic"),
        }
        if 'replica-assignment' in topic_cfg:
            cmd += " --replica-assignment %(replica-assignment)s" % {
                'replica-assignment': topic_cfg.get('replica-assignment')
            }
        else:
            cmd += " --partitions %(partitions)d --replication-factor %(replication-factor)d" % {
                'partitions': topic_cfg.get('partitions', 1),
                'replication-factor': topic_cfg.get('replication-factor', 1)
            }

        if topic_cfg.get('if-not-exists', False):
            cmd += ' --if-not-exists'

        if "configs" in topic_cfg.keys() and topic_cfg["configs"] is not None:
            for config_name, config_value in topic_cfg["configs"].items():
                cmd += " --config %s=%s" % (config_name, str(config_value))

        self.logger.info("Running topic creation command...\n%s" % cmd)
        node.account.ssh(cmd)

    def delete_topic(self, topic, node=None):
        """
        Delete a topic with the topics command
        :param topic:
        :param node:
        :return:
        """
        if node is None:
            node = self.nodes[0]
        self.logger.info("Deleting topic %s" % topic)

        force_use_zk_connection = not self.all_nodes_topic_command_supports_bootstrap_server()

        cmd = fix_opts_for_new_jvm(node)
        cmd += "%s --topic %s --delete" % \
               (self.kafka_topics_cmd_with_optional_security_settings(node, force_use_zk_connection), topic)
        self.logger.info("Running topic delete command...\n%s" % cmd)
        node.account.ssh(cmd)

    def describe_topic(self, topic, node=None):
        if node is None:
            node = self.nodes[0]

        force_use_zk_connection = not self.all_nodes_topic_command_supports_bootstrap_server()

        cmd = fix_opts_for_new_jvm(node)
        cmd += "%s --topic %s --describe" % \
               (self.kafka_topics_cmd_with_optional_security_settings(node, force_use_zk_connection), topic)

        self.logger.info("Running topic describe command...\n%s" % cmd)
        output = ""
        for line in node.account.ssh_capture(cmd):
            output += line
        return output

    def list_topics(self, node=None):
        if node is None:
            node = self.nodes[0]

        force_use_zk_connection = not self.all_nodes_topic_command_supports_bootstrap_server()

        cmd = fix_opts_for_new_jvm(node)
        cmd += "%s --list" % (self.kafka_topics_cmd_with_optional_security_settings(node, force_use_zk_connection))
        for line in node.account.ssh_capture(cmd):
            if not line.startswith("SLF4J"):
                yield line.rstrip()

    def alter_message_format(self, topic, msg_format_version, node=None):
        if node is None:
            node = self.nodes[0]
        self.logger.info("Altering message format version for topic %s with format %s", topic, msg_format_version)

        force_use_zk_connection = not self.all_nodes_configs_command_uses_bootstrap_server()

        cmd = fix_opts_for_new_jvm(node)
        cmd += "%s --entity-name %s --entity-type topics --alter --add-config message.format.version=%s" % \
              (self.kafka_configs_cmd_with_optional_security_settings(node, force_use_zk_connection), topic, msg_format_version)
        self.logger.info("Running alter message format command...\n%s" % cmd)
        node.account.ssh(cmd)

    def set_unclean_leader_election(self, topic, value=True, node=None):
        if node is None:
            node = self.nodes[0]
        if value is True:
            self.logger.info("Enabling unclean leader election for topic %s", topic)
        else:
            self.logger.info("Disabling unclean leader election for topic %s", topic)

        force_use_zk_connection = not self.all_nodes_configs_command_uses_bootstrap_server()

        cmd = fix_opts_for_new_jvm(node)
        cmd += "%s --entity-name %s --entity-type topics --alter --add-config unclean.leader.election.enable=%s" % \
              (self.kafka_configs_cmd_with_optional_security_settings(node, force_use_zk_connection), topic, str(value).lower())
        self.logger.info("Running alter unclean leader command...\n%s" % cmd)
        node.account.ssh(cmd)

    def kafka_acls_cmd_with_optional_security_settings(self, node, force_use_zk_connection, kafka_security_protocol = None, override_command_config = None):
        force_use_zk_connection = force_use_zk_connection or not self.all_nodes_acl_command_supports_bootstrap_server
        if force_use_zk_connection:
            bootstrap_server_or_authorizer_zk_props = "--authorizer-properties zookeeper.connect=%s" % (self.zk_connect_setting())
            skip_optional_security_settings = True
        else:
            if kafka_security_protocol is None:
                # it wasn't specified, so use the inter-broker security protocol if it is PLAINTEXT,
                # otherwise use the client security protocol
                if self.interbroker_security_protocol == SecurityConfig.PLAINTEXT:
                    security_protocol_to_use = SecurityConfig.PLAINTEXT
                else:
                    security_protocol_to_use = self.security_protocol
            else:
                security_protocol_to_use = kafka_security_protocol
            bootstrap_server_or_authorizer_zk_props = "--bootstrap-server %s" % (self.bootstrap_servers(security_protocol_to_use))
            skip_optional_security_settings = security_protocol_to_use == SecurityConfig.PLAINTEXT
        if skip_optional_security_settings:
            optional_jass_krb_system_props_prefix = ""
            optional_command_config_suffix = ""
        else:
            # we need security configs because aren't going to ZooKeeper and we aren't using PLAINTEXT
            if (security_protocol_to_use == self.interbroker_security_protocol):
                # configure JAAS to provide the broker's credentials
                # since this is an authenticating cluster and we are going to use the inter-broker security protocol
                jaas_conf_prop = KafkaService.ADMIN_CLIENT_AS_BROKER_JAAS_CONF_PROPERTY
                use_inter_broker_mechanism_for_client = True
            else:
                # configure JAAS to provide the typical client credentials
                jaas_conf_prop = KafkaService.JAAS_CONF_PROPERTY
                use_inter_broker_mechanism_for_client = False
            optional_jass_krb_system_props_prefix = "KAFKA_OPTS='-D%s -D%s' " % (jaas_conf_prop, KafkaService.KRB5_CONF)
            if override_command_config is None:
                optional_command_config_suffix = " --command-config <(echo '%s')" % (self.security_config.client_config(use_inter_broker_mechanism_for_client = use_inter_broker_mechanism_for_client))
            else:
                optional_command_config_suffix = " --command-config %s" % (override_command_config)
        kafka_acls_script = self.path.script("kafka-acls.sh", node)
        return "%s%s %s%s" % \
               (optional_jass_krb_system_props_prefix, kafka_acls_script,
                bootstrap_server_or_authorizer_zk_props, optional_command_config_suffix)

    def run_cli_tool(self, node, cmd):
        output = ""
        self.logger.debug(cmd)
        for line in node.account.ssh_capture(cmd):
            if not line.startswith("SLF4J"):
                output += line
        self.logger.debug(output)
        return output

    def parse_describe_topic(self, topic_description):
        """Parse output of kafka-topics.sh --describe (or describe_topic() method above), which is a string of form
        PartitionCount:2\tReplicationFactor:2\tConfigs:
            Topic: test_topic\ttPartition: 0\tLeader: 3\tReplicas: 3,1\tIsr: 3,1
            Topic: test_topic\tPartition: 1\tLeader: 1\tReplicas: 1,2\tIsr: 1,2
        into a dictionary structure appropriate for use with reassign-partitions tool:
        {
            "partitions": [
                {"topic": "test_topic", "partition": 0, "replicas": [3, 1]},
                {"topic": "test_topic", "partition": 1, "replicas": [1, 2]}
            ]
        }
        """
        lines = map(lambda x: x.strip(), topic_description.split("\n"))
        partitions = []
        for line in lines:
            m = re.match(".*Leader:.*", line)
            if m is None:
                continue

            fields = line.split("\t")
            # ["Partition: 4", "Leader: 0"] -> ["4", "0"]
            fields = list(map(lambda x: x.split(" ")[1], fields))
            partitions.append(
                {"topic": fields[0],
                 "partition": int(fields[1]),
                 "replicas": list(map(int, fields[3].split(',')))})
        return {"partitions": partitions}


    def _connect_setting_reassign_partitions(self, node):
        if self.all_nodes_reassign_partitions_command_supports_bootstrap_server():
            return "--bootstrap-server %s " % self.bootstrap_servers(self.security_protocol)
        else:
            return "--zookeeper %s " % self.zk_connect_setting()

    def verify_reassign_partitions(self, reassignment, node=None):
        """Run the reassign partitions admin tool in "verify" mode
        """
        if node is None:
            node = self.nodes[0]

        json_file = "/tmp/%s_reassign.json" % str(time.time())

        # reassignment to json
        json_str = json.dumps(reassignment)
        json_str = json.dumps(json_str)

        # create command
        cmd = fix_opts_for_new_jvm(node)
        cmd += "echo %s > %s && " % (json_str, json_file)
        cmd += "%s " % self.path.script("kafka-reassign-partitions.sh", node)
        cmd += self._connect_setting_reassign_partitions(node)
        cmd += "--reassignment-json-file %s " % json_file
        cmd += "--verify "
        cmd += "&& sleep 1 && rm -f %s" % json_file

        # send command
        self.logger.info("Verifying partition reassignment...")
        self.logger.debug(cmd)
        output = ""
        for line in node.account.ssh_capture(cmd):
            output += line

        self.logger.debug(output)

        if re.match(".*Reassignment of partition.*failed.*",
                    output.replace('\n', '')) is not None:
            return False

        if re.match(".*is still in progress.*",
                    output.replace('\n', '')) is not None:
            return False

        return True

    def execute_reassign_partitions(self, reassignment, node=None,
                                    throttle=None):
        """Run the reassign partitions admin tool in "verify" mode
        """
        if node is None:
            node = self.nodes[0]
        json_file = "/tmp/%s_reassign.json" % str(time.time())

        # reassignment to json
        json_str = json.dumps(reassignment)
        json_str = json.dumps(json_str)

        # create command
        cmd = fix_opts_for_new_jvm(node)
        cmd += "echo %s > %s && " % (json_str, json_file)
        cmd += "%s " % self.path.script( "kafka-reassign-partitions.sh", node)
        cmd += self._connect_setting_reassign_partitions(node)
        cmd += "--reassignment-json-file %s " % json_file
        cmd += "--execute"
        if throttle is not None:
            cmd += " --throttle %d" % throttle
        cmd += " && sleep 1 && rm -f %s" % json_file

        # send command
        self.logger.info("Executing parition reassignment...")
        self.logger.debug(cmd)
        output = ""
        for line in node.account.ssh_capture(cmd):
            output += line

        self.logger.debug("Verify partition reassignment:")
        self.logger.debug(output)

    def search_data_files(self, topic, messages):
        """Check if a set of messages made it into the Kakfa data files. Note that
        this method takes no account of replication. It simply looks for the
        payload in all the partition files of the specified topic. 'messages' should be
        an array of numbers. The list of missing messages is returned.
        """
        payload_match = "payload: " + "$|payload: ".join(str(x) for x in messages) + "$"
        found = set([])
        self.logger.debug("number of unique missing messages we will search for: %d",
                          len(messages))
        for node in self.nodes:
            # Grab all .log files in directories prefixed with this topic
            files = node.account.ssh_capture("find %s* -regex  '.*/%s-.*/[^/]*.log'" % (KafkaService.DATA_LOG_DIR_PREFIX, topic))

            # Check each data file to see if it contains the messages we want
            for log in files:
                cmd = fix_opts_for_new_jvm(node)
                cmd += "%s kafka.tools.DumpLogSegments --print-data-log --files %s | grep -E \"%s\"" % \
                      (self.path.script("kafka-run-class.sh", node), log.strip(), payload_match)

                for line in node.account.ssh_capture(cmd, allow_fail=True):
                    for val in messages:
                        if line.strip().endswith("payload: "+str(val)):
                            self.logger.debug("Found %s in data-file [%s] in line: [%s]" % (val, log.strip(), line.strip()))
                            found.add(val)

        self.logger.debug("Number of unique messages found in the log: %d",
                          len(found))
        missing = list(set(messages) - found)

        if len(missing) > 0:
            self.logger.warn("The following values were not found in the data files: " + str(missing))

        return missing

    def restart_cluster(self, clean_shutdown=True, timeout_sec=60, after_each_broker_restart=None, *args):
        for node in self.nodes:
            self.restart_node(node, clean_shutdown=clean_shutdown, timeout_sec=timeout_sec)
            if after_each_broker_restart is not None:
                after_each_broker_restart(*args)

    def restart_node(self, node, clean_shutdown=True, timeout_sec=60):
        """Restart the given node."""
        self.stop_node(node, clean_shutdown, timeout_sec)
        self.start_node(node, timeout_sec)

    def _describe_topic_line_for_partition(self, partition, describe_topic_output):
        # Lines look like this: Topic: test_topic	Partition: 0	Leader: 3	Replicas: 3,2	Isr: 3,2
        grep_for = "Partition: %i\t" % (partition) # be sure to include trailing tab, otherwise 1 might match 10 (for example)
        found_lines = [line for line in describe_topic_output.splitlines() if grep_for in line]
        return None if not found_lines else found_lines[0]

    def isr_idx_list(self, topic, partition=0):
        """ Get in-sync replica list the given topic and partition.
        """
        node = self.nodes[0]
        if not self.all_nodes_topic_command_supports_bootstrap_server():
            self.logger.debug("Querying zookeeper to find in-sync replicas for topic %s and partition %d" % (topic, partition))
            zk_path = "/brokers/topics/%s/partitions/%d/state" % (topic, partition)
            partition_state = self.zk.query(zk_path, chroot=self.zk_chroot)

            if partition_state is None:
                raise Exception("Error finding partition state for topic %s and partition %d." % (topic, partition))

            partition_state = json.loads(partition_state)
            self.logger.info(partition_state)

            isr_idx_list = partition_state["isr"]
        else:
            self.logger.debug("Querying Kafka Admin API to find in-sync replicas for topic %s and partition %d" % (topic, partition))
            describe_output = self.describe_topic(topic, node)
            self.logger.debug(describe_output)
            requested_partition_line = self._describe_topic_line_for_partition(partition, describe_output)
            # e.g. Topic: test_topic	Partition: 0	Leader: 3	Replicas: 3,2	Isr: 3,2
            if not requested_partition_line:
                raise Exception("Error finding partition state for topic %s and partition %d." % (topic, partition))
            isr_csv = requested_partition_line.split()[9] # 10th column from above
            isr_idx_list = [int(i) for i in isr_csv.split(",")]

        self.logger.info("Isr for topic %s and partition %d is now: %s" % (topic, partition, isr_idx_list))
        return isr_idx_list

    def replicas(self, topic, partition=0):
        """ Get the assigned replicas for the given topic and partition.
        """
        node = self.nodes[0]
        if not self.all_nodes_topic_command_supports_bootstrap_server():
            self.logger.debug("Querying zookeeper to find assigned replicas for topic %s and partition %d" % (topic, partition))
            zk_path = "/brokers/topics/%s" % (topic)
            assignment = self.zk.query(zk_path, chroot=self.zk_chroot)

            if assignment is None:
                raise Exception("Error finding partition state for topic %s and partition %d." % (topic, partition))

            assignment = json.loads(assignment)
            self.logger.info(assignment)

            replicas = assignment["partitions"][str(partition)]
        else:
            self.logger.debug("Querying Kafka Admin API to find replicas for topic %s and partition %d" % (topic, partition))
            describe_output = self.describe_topic(topic, node)
            self.logger.debug(describe_output)
            requested_partition_line = self._describe_topic_line_for_partition(partition, describe_output)
            # e.g. Topic: test_topic	Partition: 0	Leader: 3	Replicas: 3,2	Isr: 3,2
            if not requested_partition_line:
                raise Exception("Error finding partition state for topic %s and partition %d." % (topic, partition))
            isr_csv = requested_partition_line.split()[7] # 8th column from above
            replicas = [int(i) for i in isr_csv.split(",")]

        self.logger.info("Assigned replicas for topic %s and partition %d is now: %s" % (topic, partition, replicas))
        return [self.get_node(replica) for replica in replicas]

    def leader(self, topic, partition=0):
        """ Get the leader replica for the given topic and partition.
        """
        node = self.nodes[0]
        if not self.all_nodes_topic_command_supports_bootstrap_server():
            self.logger.debug("Querying zookeeper to find leader replica for topic %s and partition %d" % (topic, partition))
            zk_path = "/brokers/topics/%s/partitions/%d/state" % (topic, partition)
            partition_state = self.zk.query(zk_path, chroot=self.zk_chroot)

            if partition_state is None:
                raise Exception("Error finding partition state for topic %s and partition %d." % (topic, partition))

            partition_state = json.loads(partition_state)
            self.logger.info(partition_state)

            leader_idx = int(partition_state["leader"])
        else:
            self.logger.debug("Querying Kafka Admin API to find leader for topic %s and partition %d" % (topic, partition))
            describe_output = self.describe_topic(topic, node)
            self.logger.debug(describe_output)
            requested_partition_line = self._describe_topic_line_for_partition(partition, describe_output)
            # e.g. Topic: test_topic	Partition: 0	Leader: 3	Replicas: 3,2	Isr: 3,2
            if not requested_partition_line:
                raise Exception("Error finding partition state for topic %s and partition %d." % (topic, partition))
            leader_idx = int(requested_partition_line.split()[5]) # 6th column from above

        self.logger.info("Leader for topic %s and partition %d is now: %d" % (topic, partition, leader_idx))
        return self.get_node(leader_idx)

    def cluster_id(self):
        """ Get the current cluster id
        """
        self.logger.debug("Querying ZooKeeper to retrieve cluster id")
        cluster = self.zk.query("/cluster/id", chroot=self.zk_chroot)

        try:
            return json.loads(cluster)['id'] if cluster else None
        except:
            self.logger.debug("Data in /cluster/id znode could not be parsed. Data = %s" % cluster)
            raise

    def check_protocol_errors(self, node):
        """ Checks for common protocol exceptions due to invalid inter broker protocol handling.
            While such errors can and should be checked in other ways, checking the logs is a worthwhile failsafe.
            """
        for node in self.nodes:
            exit_code = node.account.ssh("grep -e 'java.lang.IllegalArgumentException: Invalid version' -e SchemaException %s/*"
                                         % KafkaService.OPERATIONAL_LOG_DEBUG_DIR, allow_fail=True)
            if exit_code != 1:
                return False
        return True

    def list_consumer_groups(self, node=None, command_config=None):
        """ Get list of consumer groups.
        """
        if node is None:
            node = self.nodes[0]
        consumer_group_script = self.path.script("kafka-consumer-groups.sh", node)

        if command_config is None:
            command_config = ""
        else:
            command_config = "--command-config " + command_config

        cmd = fix_opts_for_new_jvm(node)
        cmd += "%s --bootstrap-server %s %s --list" % \
              (consumer_group_script,
               self.bootstrap_servers(self.security_protocol),
               command_config)
        return self.run_cli_tool(node, cmd)

    def describe_consumer_group(self, group, node=None, command_config=None):
        """ Describe a consumer group.
        """
        if node is None:
            node = self.nodes[0]
        consumer_group_script = self.path.script("kafka-consumer-groups.sh", node)

        if command_config is None:
            command_config = ""
        else:
            command_config = "--command-config " + command_config

        cmd = fix_opts_for_new_jvm(node)
        cmd += "%s --bootstrap-server %s %s --group %s --describe" % \
              (consumer_group_script,
               self.bootstrap_servers(self.security_protocol),
               command_config, group)

        output = ""
        self.logger.debug(cmd)
        for line in node.account.ssh_capture(cmd):
            if not (line.startswith("SLF4J") or line.startswith("TOPIC") or line.startswith("Could not fetch offset")):
                output += line
        self.logger.debug(output)
        return output

    def zk_connect_setting(self):
        return self.zk.connect_setting(self.zk_chroot, self.zk_client_secure)

    def __bootstrap_servers(self, port, validate=True, offline_nodes=[]):
        if validate and not port.open:
            raise ValueError("We are retrieving bootstrap servers for the port: %s which is not currently open. - " %
                             str(port.port_number))

        return ','.join([node.account.hostname + ":" + str(port.port_number)
                         for node in self.nodes
                         if node not in offline_nodes])

    def bootstrap_servers(self, protocol='PLAINTEXT', validate=True, offline_nodes=[]):
        """Return comma-delimited list of brokers in this cluster formatted as HOSTNAME1:PORT1,HOSTNAME:PORT2,...

        This is the format expected by many config files.
        """
        port_mapping = self.port_mappings[protocol]
        self.logger.info("Bootstrap client port is: " + str(port_mapping.port_number))
        return self.__bootstrap_servers(port_mapping, validate, offline_nodes)

    def controller(self):
        """ Get the controller node
        """
        self.logger.debug("Querying zookeeper to find controller broker")
        controller_info = self.zk.query("/controller", chroot=self.zk_chroot)

        if controller_info is None:
            raise Exception("Error finding controller info")

        controller_info = json.loads(controller_info)
        self.logger.debug(controller_info)

        controller_idx = int(controller_info["brokerid"])
        self.logger.info("Controller's ID: %d" % (controller_idx))
        return self.get_node(controller_idx)

    def is_registered(self, node):
        """
        Check whether a broker is registered in Zookeeper
        """
        self.logger.debug("Querying zookeeper to see if broker %s is registered", str(node))
        broker_info = self.zk.query("/brokers/ids/%s" % self.idx(node), chroot=self.zk_chroot)
        self.logger.debug("Broker info: %s", broker_info)
        return broker_info is not None

    def get_offset_shell(self, topic, partitions, max_wait_ms, offsets, time):
        node = self.nodes[0]

        cmd = fix_opts_for_new_jvm(node)
        cmd += self.path.script("kafka-run-class.sh", node)
        cmd += " kafka.tools.GetOffsetShell"
        cmd += " --topic %s --broker-list %s --max-wait-ms %s --offsets %s --time %s" % (topic, self.bootstrap_servers(self.security_protocol), max_wait_ms, offsets, time)

        if partitions:
            cmd += '  --partitions %s' % partitions

        cmd += " 2>> %s/get_offset_shell.log" % KafkaService.PERSISTENT_ROOT
        cmd += " | tee -a %s/get_offset_shell.log &" % KafkaService.PERSISTENT_ROOT
        output = ""
        self.logger.debug(cmd)
        for line in node.account.ssh_capture(cmd):
            output += line
        self.logger.debug(output)
        return output

    def java_class_name(self):
        return "kafka.Kafka"

    def deprecated_cp_java_class_name(self):
        return "io.confluent.support.metrics.SupportedKafka"
