Add Kafka export plugin #858

NEWS

@@ -8,6 +8,7 @@ Version 2.9.0
 Enhancements and new features:
 
     * Add a Prometheus export module (issue #930)
+    * Add a Kafka export module (issue #858)
     * Port in the -c URI (-c hostname:port) (issue #996)
 
 Bugs corrected:

conf/glances.conf

@@ -349,6 +349,14 @@ db=glances
 #user=root
 #password=root
 
+[kafka]
+# Configuration for the --export-kafka option
+# http://kafka.apache.org/
+host=localhost
+port=9092
+topic=glances
+#compression=gzip
+
 [zeromq]
 # Configuration for the --export-zeromq option
 # http://www.zeromq.org

docs/gw/index.rst

@@ -14,6 +14,7 @@ to providing stats to multiple services (see list below).
    couchdb
    elastic
    influxdb
+   kafka
    opentsdb
    prometheus
    rabbitmq

docs/gw/kafka.rst

+.. _kafka:
+
+Kafka
+=====
+
+You can export statistics to a ``Kafka`` server.
+The connection should be defined in the Glances configuration file as
+following:
+
+.. code-block:: ini
+
+    [kafka]
+    host=localhost
+    port=9092
+    topic=glances
+    #compression=gzip
+
+Note: you can enable the compression but it consume CPU on your host.
+
+and run Glances with:
+
+.. code-block:: console
+
+    $ glances --export-kafka
+
+Stats  are sent in native ``JSON`` format to the topic:
+
+- ``key``: plugin name
+- ``value``: JSON dict
+
+Example of record for the memory plugin:
+
+.. code-block::
+
+    ConsumerRecord(topic=u'glances', partition=0, offset=1305, timestamp=1490460592248, timestamp_type=0, key='mem', value=u'{"available": 2094710784, "used": 5777428480, "cached": 2513543168, "mem_careful": 50.0, "percent": 73.4, "free": 2094710784, "mem_critical": 90.0, "inactive": 2361626624, "shared": 475504640, "history_size": 28800.0, "mem_warning": 70.0, "total": 7872139264, "active": 4834361344, "buffers": 160112640}', checksum=214895201, serialized_key_size=3, serialized_value_size=303)
+
+Python code example to consume Kafka Glances plugin:
+
+.. code-block:: python
+
+    from kafka import KafkaConsumer
+    import json
+
+    consumer = KafkaConsumer('glances', value_deserializer=json.loads)
+    for s in consumer:
+      print s

glances/exports/glances_kafka.py

+# -*- coding: utf-8 -*-
+#
+# This file is part of Glances.
+#
+# Copyright (C) 2017 Nicolargo <nicolas@nicolargo.com>
+#
+# Glances is free software; you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Glances is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+"""Kafka interface class."""
+
+import sys
+
+from glances.logger import logger
+from glances.compat import iteritems
+from glances.exports.glances_export import GlancesExport
+
+from kafka import KafkaProducer
+import json
+
+
+class Export(GlancesExport):
+
+    """This class manages the Kafka export module."""
+
+    def __init__(self, config=None, args=None):
+        """Init the Kafka export IF."""
+        super(Export, self).__init__(config=config, args=args)
+
+        # Mandatories configuration keys (additional to host and port)
+        self.topic = None
+
+        # Optionals configuration keys
+        self.compression = None
+
+        # Load the Cassandra configuration file section
+        self.export_enable = self.load_conf('kafka',
+                                            mandatories=['host', 'port', 'topic'],
+                                            options=['compression'])
+        if not self.export_enable:
+            sys.exit(2)
+
+        # Init the kafka client
+        self.client = self.init()
+
+    def init(self):
+        """Init the connection to the Kafka server."""
+        if not self.export_enable:
+            return None
+
+        # Build the server URI with host and port
+        server_uri = '{}:{}'.format(self.host, self.port)
+
+        try:
+            s = KafkaProducer(bootstrap_servers=server_uri,
+                              value_serializer=lambda v: json.dumps(v).encode('utf-8'),
+                              compression_type=self.compression)
+        except Exception as e:
+            logger.critical("Cannot connect to Kafka server %s (%s)" % (server_uri, e))
+            sys.exit(2)
+        else:
+            logger.info("Connected to the Kafka server %s" % server_uri)
+
+        return s
+
+    def export(self, name, columns, points):
+        """Write the points to the kafka server."""
+        logger.debug("Export {} stats to Kafka".format(name))
+
+        # Create DB input
+        data = dict(zip(columns, points))
+
+        # Send stats to the kafka topic
+        # key=<plugin name>
+        # value=JSON dict
+        try:
+            self.client.send(self.topic,
+                             key=name,
+                             value=data)
+        except Exception as e:
+            logger.error("Cannot export {} stats to Kafka ({})".format(name, e))
+
+    def exit(self):
+        """Close the Kafka export module."""
+        # To ensure all connections are properly closed
+        self.client.flush()
+        self.client.close()
+        # Call the father method
+        super(Export, self).exit()

glances/main.py

@@ -181,6 +181,8 @@ Examples of use:
                             dest='export_elasticsearch', help='export stats to an ElasticSearch server (elasticsearch lib needed)')
         parser.add_argument('--export-influxdb', action='store_true', default=False,
                             dest='export_influxdb', help='export stats to an InfluxDB server (influxdb lib needed)')
+        parser.add_argument('--export-kafka', action='store_true', default=False,
+                            dest='export_kafka', help='export stats to a Kafka server (kafka-python lib needed)')
         parser.add_argument('--export-opentsdb', action='store_true', default=False,
                             dest='export_opentsdb', help='export stats to an OpenTSDB server (potsdb lib needed)')
         parser.add_argument('--export-prometheus', action='store_true', default=False,

optional-requirements.txt

@@ -5,6 +5,7 @@ couchdb
 docker
 elasticsearch
 influxdb
+kafka-python
 matplotlib
 netifaces
 nvidia-ml-py; python_version == "2.7"

setup.py

@@ -85,8 +85,8 @@ setup(
         'chart': ['matplotlib'],
         'docker': ['docker>=2.0.0'],
         'export': ['bernhard', 'cassandra-driver', 'couchdb', 'elasticsearch',
-                   'influxdb>=1.0.0', 'pika', 'potsdb', 'prometheus_client',
-                   'pyzmq', 'statsd'],
+                   'influxdb>=1.0.0', 'kafka-python', 'pika', 'potsdb',
+                   'prometheus_client', 'pyzmq', 'statsd'],
         'folders:python_version<"3.5"': ['scandir'],
         'gpu:python_version=="2.7"': ['nvidia-ml-py'],
         'ip': ['netifaces'],