Add KafkaAdmin class

Requires cluster version > 0.10.0.0, and uses new wire protocol
classes to do many things via broker connection that previously
needed to be done directly in zookeeper.

Author: llamahunter

kafka/__init__.py

@@ -18,6 +18,7 @@ def emit(self, record):
 logging.getLogger(__name__).addHandler(NullHandler())
 
 
+from kafka.admin import KafkaAdmin
 from kafka.consumer import KafkaConsumer
 from kafka.consumer.subscription_state import ConsumerRebalanceListener
 from kafka.producer import KafkaProducer
@@ -46,6 +47,7 @@ def __init__(self, *args, **kwargs):
 
 
 __all__ = [
+    'KafkaAdmin',
     'KafkaConsumer', 'KafkaProducer', 'KafkaClient', 'BrokerConnection',
     'SimpleClient', 'SimpleProducer', 'KeyedProducer',
     'RoundRobinPartitioner', 'HashedPartitioner',

kafka/admin/__init__.py

@@ -0,0 +1,10 @@
+from __future__ import absolute_import
+
+from kafka.admin.config_resource import ConfigResource, ConfigResourceType
+from kafka.admin.kafka import KafkaAdmin
+from kafka.admin.new_topic import NewTopic
+from kafka.admin.new_partitions import NewPartitions
+
+__all__ = [
+    'ConfigResource', 'ConfigResourceType', 'KafkaAdmin', 'NewTopic', 'NewPartitions'
+]

kafka/admin/config_resource.py

@@ -0,0 +1,36 @@
+from __future__ import absolute_import
+
+# enum in stdlib as of py3.4
+try:
+    from enum import IntEnum  # pylint: disable=import-error
+except ImportError:
+    # vendored backport module
+    from kafka.vendor.enum34 import IntEnum
+
+
+class ConfigResourceType(IntEnum):
+    """An enumerated type of config resources"""
+
+    BROKER = 4,
+    TOPIC = 2
+
+
+class ConfigResource(object):
+    """A class for specifying config resources.
+    Arguments:
+        resource_type (ConfigResourceType): the type of kafka resource
+        name (string): The name of the kafka resource
+        configs ({key : value}): A  maps of config keys to values.
+    """
+
+    def __init__(
+            self,
+            resource_type,
+            name,
+            configs=None
+    ):
+        if not isinstance(resource_type, (ConfigResourceType)):
+            resource_type = ConfigResourceType[str(resource_type).upper()] # pylint: disable-msg=unsubscriptable-object
+        self.resource_type = resource_type
+        self.name = name
+        self.configs = configs

kafka/admin/kafka.py

@@ -0,0 +1,19 @@
+from __future__ import absolute_import
+
+
+class NewPartitions(object):
+    """A class for new partition creation on existing topics.  Note that the length of new_assignments, if specified,
+    must be the difference between the new total number of partitions and the existing number of partitions.
+    Arguments:
+        total_count (int): the total number of partitions that should exist on the topic
+        new_assignments ([[int]]): an array of arrays of replica assignments for new partitions.
+            If not set, broker assigns replicas per an internal algorithm.
+    """
+
+    def __init__(
+        self,
+        total_count,
+        new_assignments=None
+    ):
+        self.total_count = total_count
+        self.new_assignments = new_assignments

kafka/admin/new_partitions.py

@@ -0,0 +1,34 @@
+from __future__ import absolute_import
+
+from kafka.errors import IllegalArgumentError
+
+
+class NewTopic(object):
+    """ A class for new topic creation
+    Arguments:
+        name (string): name of the topic
+        num_partitions (int): number of partitions
+            or -1 if replica_assignment has been specified
+        replication_factor (int): replication factor or -1 if
+            replica assignment is specified
+        replica_assignment (dict of int: [int]): A mapping containing
+            partition id and replicas to assign to it.
+        topic_configs (dict of str: str): A mapping of config key
+            and value for the topic.
+    """
+
+    def __init__(
+            self,
+            name,
+            num_partitions,
+            replication_factor,
+            replica_assignments=None,
+            topic_configs=None,
+    ):
+        if not (num_partitions == -1 or replication_factor == -1) ^ (replica_assignments is None):
+            raise IllegalArgumentError('either num_partitions/replication_factor or replica_assignment must be specified')
+        self.name = name
+        self.num_partitions = num_partitions
+        self.replication_factor = replication_factor
+        self.replica_assignments = replica_assignments or {}
+        self.topic_configs = topic_configs or {}

kafka/admin/new_topic.py

@@ -196,6 +196,7 @@ def __init__(self, **configs):
         self._metadata_refresh_in_progress = False
         self._selector = self.config['selector']()
         self._conns = Dict()  # object to support weakrefs
+        self._api_versions = None
         self._connecting = set()
         self._refresh_on_disconnects = True
         self._last_bootstrap = 0
@@ -808,6 +809,17 @@ def refresh_done(val_or_error):
         # to let us know the selected connection might be usable again.
         return float('inf')
 
+    def get_api_versions(self):
+        """Return the ApiVersions map, if available.
+
+        Note: A call to check_version must previously have succeeded and returned
+        version 0.10.0 or later
+
+        Returns: a map of dict mapping {api_key : (min_version, max_version)},
+        or None if ApiVersion is not supported by the kafka cluster.
+        """
+        return self._api_versions
+
     def check_version(self, node_id=None, timeout=2, strict=False):
         """Attempt to guess the version of a Kafka broker.
 
@@ -841,6 +853,10 @@ def check_version(self, node_id=None, timeout=2, strict=False):
             try:
                 remaining = end - time.time()
                 version = conn.check_version(timeout=remaining, strict=strict, topics=list(self.config['bootstrap_topics_filter']))
+                if version >= (0, 10, 0):
+                    # cache the api versions map if it's available (starting
+                    # in 0.10 cluster version)
+                    self._api_versions = conn.get_api_versions()
                 return version
             except Errors.NodeNotReadyError:
                 # Only raise to user if this is a node-specific request

kafka/client_async.py

@@ -873,6 +873,16 @@ def _handle_api_version_response(self, response):
         ])
         return self._api_versions
 
+    def get_api_versions(self):
+        version = self.check_version()
+        if version < (0, 10, 0):
+            raise Errors.UnsupportedVersionError(
+                "ApiVersion not supported by cluster version {} < 0.10.0"
+                .format(version))
+        # _api_versions is set as a side effect of check_versions() on a cluster
+        # that supports 0.10.0 or later
+        return self._api_versions;
+
     def _infer_broker_version_from_api_versions(self, api_versions):
         # The logic here is to check the list of supported request versions
         # in reverse order. As soon as we find one that works, return it

kafka/conn.py

@@ -44,4 +44,9 @@
     33: 'AlterConfigs',
     36: 'SaslAuthenticate',
     37: 'CreatePartitions',
+    38: 'CreateDelegationToken',
+    39: 'RenewDelegationToken',
+    40: 'ExpireDelegationToken',
+    41: 'DescribeDelegationToken',
+    42: 'DeleteGroups',
 }

kafka/protocol/__init__.py

@@ -0,0 +1,47 @@
+import pytest
+
+import kafka.admin
+from kafka.errors import IllegalArgumentError
+
+
+def test_config_resource():
+    with pytest.raises(KeyError):
+        bad_resource = kafka.admin.ConfigResource('something', 'foo')
+    good_resource = kafka.admin.ConfigResource('broker', 'bar')
+    assert(good_resource.resource_type == kafka.admin.ConfigResourceType.BROKER)
+    assert(good_resource.name == 'bar')
+    assert(good_resource.configs is None)
+    good_resource = kafka.admin.ConfigResource(kafka.admin.ConfigResourceType.TOPIC, 'baz', {'frob' : 'nob'})
+    assert(good_resource.resource_type == kafka.admin.ConfigResourceType.TOPIC)
+    assert(good_resource.name == 'baz')
+    assert(good_resource.configs == {'frob' : 'nob'})
+
+
+def test_new_partitions():
+    good_partitions = kafka.admin.NewPartitions(6)
+    assert(good_partitions.total_count == 6)
+    assert(good_partitions.new_assignments is None)
+    good_partitions = kafka.admin.NewPartitions(7, [[1, 2, 3]])
+    assert(good_partitions.total_count == 7)
+    assert(good_partitions.new_assignments == [[1, 2, 3]])
+
+
+def test_new_topic():
+    with pytest.raises(IllegalArgumentError):
+        bad_topic = kafka.admin.NewTopic('foo', -1, -1)
+    with pytest.raises(IllegalArgumentError):
+        bad_topic = kafka.admin.NewTopic('foo', 1, -1)
+    with pytest.raises(IllegalArgumentError):
+        bad_topic = kafka.admin.NewTopic('foo', 1, 1, {1 : [1, 1, 1]})
+    good_topic = kafka.admin.NewTopic('foo', 1, 2)
+    assert(good_topic.name == 'foo')
+    assert(good_topic.num_partitions == 1)
+    assert(good_topic.replication_factor == 2)
+    assert(good_topic.replica_assignments == {})
+    assert(good_topic.topic_configs == {})
+    good_topic = kafka.admin.NewTopic('bar', -1, -1, {1 : [1, 2, 3]}, {'key' : 'value'})
+    assert(good_topic.name == 'bar')
+    assert(good_topic.num_partitions == -1)
+    assert(good_topic.replication_factor == -1)
+    assert(good_topic.replica_assignments == {1: [1, 2, 3]})
+    assert(good_topic.topic_configs == {'key' : 'value'})