home-assistant/homeassistant/components/apache_kafka/__init__.py
Paulus Schoutsen 4de97abc3a Black
2019-07-31 12:25:30 -07:00

117 lines
3 KiB
Python

"""Support for Apache Kafka."""
from datetime import datetime
import json
import logging
from aiokafka import AIOKafkaProducer
import voluptuous as vol
from homeassistant.const import (
CONF_IP_ADDRESS,
CONF_PORT,
EVENT_HOMEASSISTANT_STOP,
EVENT_STATE_CHANGED,
STATE_UNAVAILABLE,
STATE_UNKNOWN,
)
import homeassistant.helpers.config_validation as cv
from homeassistant.helpers.entityfilter import FILTER_SCHEMA
_LOGGER = logging.getLogger(__name__)
DOMAIN = "apache_kafka"
CONF_FILTER = "filter"
CONF_TOPIC = "topic"
CONFIG_SCHEMA = vol.Schema(
{
DOMAIN: vol.Schema(
{
vol.Required(CONF_IP_ADDRESS): cv.string,
vol.Required(CONF_PORT): cv.port,
vol.Required(CONF_TOPIC): cv.string,
vol.Optional(CONF_FILTER, default={}): FILTER_SCHEMA,
}
)
},
extra=vol.ALLOW_EXTRA,
)
async def async_setup(hass, config):
"""Activate the Apache Kafka integration."""
conf = config[DOMAIN]
kafka = hass.data[DOMAIN] = KafkaManager(
hass,
conf[CONF_IP_ADDRESS],
conf[CONF_PORT],
conf[CONF_TOPIC],
conf[CONF_FILTER],
)
hass.bus.async_listen(EVENT_HOMEASSISTANT_STOP, kafka.shutdown())
await kafka.start()
return True
class DateTimeJSONEncoder(json.JSONEncoder):
"""Encode python objects.
Additionally add encoding for datetime objects as isoformat.
"""
def default(self, o): # pylint: disable=E0202
"""Implement encoding logic."""
if isinstance(o, datetime):
return o.isoformat()
return super().default(o)
class KafkaManager:
"""Define a manager to buffer events to Kafka."""
def __init__(self, hass, ip_address, port, topic, entities_filter):
"""Initialize."""
self._encoder = DateTimeJSONEncoder()
self._entities_filter = entities_filter
self._hass = hass
self._producer = AIOKafkaProducer(
loop=hass.loop,
bootstrap_servers="{0}:{1}".format(ip_address, port),
compression_type="gzip",
)
self._topic = topic
def _encode_event(self, event):
"""Translate events into a binary JSON payload."""
state = event.data.get("new_state")
if (
state is None
or state.state in (STATE_UNKNOWN, "", STATE_UNAVAILABLE)
or not self._entities_filter(state.entity_id)
):
return
return json.dumps(obj=state.as_dict(), default=self._encoder.encode).encode(
"utf-8"
)
async def start(self):
"""Start the Kafka manager."""
self._hass.bus.async_listen(EVENT_STATE_CHANGED, self.write)
await self._producer.start()
async def shutdown(self):
"""Shut the manager down."""
await self._producer.stop()
async def write(self, event):
"""Write a binary payload to Kafka."""
payload = self._encode_event(event)
if payload:
await self._producer.send_and_wait(self._topic, payload)