forked from platypush/platypush
211 lines
7.7 KiB
Python
211 lines
7.7 KiB
Python
import json
|
|
import os
|
|
from threading import RLock
|
|
from typing import Iterable, Optional
|
|
|
|
from google.auth import jwt
|
|
from google.cloud import pubsub_v1 as pubsub # pylint: disable=no-name-in-module
|
|
from google.api_core.exceptions import AlreadyExists, NotFound
|
|
|
|
from platypush.config import Config
|
|
from platypush.message.event.google.pubsub import GooglePubsubMessageEvent
|
|
from platypush.plugins import RunnablePlugin, action
|
|
|
|
|
|
class GooglePubsubPlugin(RunnablePlugin):
|
|
"""
|
|
Publishes and subscribes to Google Pub/Sub topics.
|
|
|
|
You'll need a Google Cloud active project and a set of credentials to use
|
|
this plugin:
|
|
|
|
1. Create a project on the `Google Cloud console
|
|
<https://console.cloud.google.com/projectcreate>`_ if you don't have
|
|
one already.
|
|
|
|
2. In the `Google Cloud API console
|
|
<https://console.cloud.google.com/apis/credentials/serviceaccountkey>`_
|
|
create a new service account key. Select "New Service Account", choose
|
|
the role "Pub/Sub Editor" and leave the key type as JSON.
|
|
|
|
3. Download the JSON service credentials file. By default Platypush
|
|
will look for the credentials file under
|
|
``<WORKDIR>/credentials/google/pubsub.json``.
|
|
|
|
"""
|
|
|
|
publisher_audience = 'https://pubsub.googleapis.com/google.pubsub.v1.Publisher'
|
|
subscriber_audience = 'https://pubsub.googleapis.com/google.pubsub.v1.Subscriber'
|
|
default_credentials_file = os.path.join(
|
|
Config.get_workdir(), 'credentials', 'google', 'pubsub.json'
|
|
)
|
|
|
|
def __init__(
|
|
self,
|
|
credentials_file: str = default_credentials_file,
|
|
topics: Iterable[str] = (),
|
|
**kwargs,
|
|
):
|
|
"""
|
|
:param credentials_file: Path to the JSON credentials file for Google
|
|
pub/sub (default: ``~/.credentials/platypush/google/pubsub.json``)
|
|
:param topics: List of topics to subscribe. You can either specify the
|
|
full topic name in the format
|
|
``projects/<project_id>/topics/<topic_name>``, where
|
|
``<project_id>`` must be the ID of your Google Pub/Sub project, or
|
|
just ``<topic_name>`` - in such case it's implied that you refer to
|
|
the ``topic_name`` under the ``project_id`` of your service
|
|
credentials.
|
|
"""
|
|
super().__init__(**kwargs)
|
|
self.credentials_file = credentials_file
|
|
self.project_id = self.get_project_id()
|
|
self.topics = topics
|
|
self._subscriber: Optional[pubsub.SubscriberClient] = None
|
|
self._subscriber_lock = RLock()
|
|
|
|
def get_project_id(self):
|
|
with open(self.credentials_file) as f:
|
|
return json.load(f).get('project_id')
|
|
|
|
def get_credentials(self, audience: str):
|
|
return jwt.Credentials.from_service_account_file(
|
|
self.credentials_file, audience=audience
|
|
)
|
|
|
|
def _norm_topic(self, topic: str):
|
|
if not topic.startswith(f'projects/{self.project_id}/topics/'):
|
|
topic = f'projects/{self.project_id}/topics/{topic}'
|
|
return topic
|
|
|
|
@action
|
|
def publish(self, topic: str, msg, **kwargs):
|
|
"""
|
|
Publish a message to a topic
|
|
|
|
:param topic: Topic/channel where the message will be delivered. You
|
|
can either specify the full topic name in the format
|
|
``projects/<project_id>/topics/<topic_name>``, where
|
|
``<project_id>`` must be the ID of your Google Pub/Sub project, or
|
|
just ``<topic_name>`` - in such case it's implied that you refer to
|
|
the ``topic_name`` under the ``project_id`` of your service
|
|
credentials.
|
|
:param msg: Message to be sent. It can be a list, a dict, or a Message object
|
|
:param kwargs: Extra arguments to be passed to .publish()
|
|
"""
|
|
credentials = self.get_credentials(self.publisher_audience)
|
|
publisher = pubsub.PublisherClient(credentials=credentials)
|
|
topic = self._norm_topic(topic)
|
|
|
|
try:
|
|
publisher.create_topic(name=topic)
|
|
except AlreadyExists:
|
|
self.logger.debug('Topic %s already exists', topic)
|
|
|
|
if isinstance(msg, (int, float)):
|
|
msg = str(msg)
|
|
if isinstance(msg, (dict, list)):
|
|
msg = json.dumps(msg)
|
|
if isinstance(msg, str):
|
|
msg = msg.encode()
|
|
|
|
publisher.publish(topic, msg, **kwargs)
|
|
|
|
@action
|
|
def send_message(self, topic: str, msg, **kwargs):
|
|
"""
|
|
Alias for :meth:`.publish`
|
|
"""
|
|
self.publish(topic=topic, msg=msg, **kwargs)
|
|
|
|
@action
|
|
def subscribe(self, topic: str):
|
|
"""
|
|
Subscribe to a topic.
|
|
|
|
:param topic: Topic/channel where the message will be delivered. You
|
|
can either specify the full topic name in the format
|
|
``projects/<project_id>/topics/<topic_name>``, where
|
|
``<project_id>`` must be the ID of your Google Pub/Sub project, or
|
|
just ``<topic_name>`` - in such case it's implied that you refer to
|
|
the ``topic_name`` under the ``project_id`` of your service
|
|
credentials.
|
|
"""
|
|
assert self._subscriber, 'Subscriber not initialized'
|
|
topic = self._norm_topic(topic)
|
|
subscription_name = '/'.join(
|
|
[*topic.split('/')[:2], 'subscriptions', topic.split('/')[-1]]
|
|
)
|
|
|
|
try:
|
|
self._subscriber.create_subscription(name=subscription_name, topic=topic)
|
|
except AlreadyExists:
|
|
self.logger.debug('Subscription %s already exists', subscription_name)
|
|
|
|
self._subscriber.subscribe(subscription_name, self._message_callback(topic))
|
|
|
|
@action
|
|
def unsubscribe(self, topic: str):
|
|
"""
|
|
Unsubscribe from a topic.
|
|
|
|
:param topic: Topic/channel where the message will be delivered. You
|
|
can either specify the full topic name in the format
|
|
``projects/<project_id>/topics/<topic_name>``, where
|
|
``<project_id>`` must be the ID of your Google Pub/Sub project, or
|
|
just ``<topic_name>`` - in such case it's implied that you refer to
|
|
the ``topic_name`` under the ``project_id`` of your service
|
|
credentials.
|
|
"""
|
|
assert self._subscriber, 'Subscriber not initialized'
|
|
topic = self._norm_topic(topic)
|
|
subscription_name = '/'.join(
|
|
[*topic.split('/')[:2], 'subscriptions', topic.split('/')[-1]]
|
|
)
|
|
|
|
try:
|
|
self._subscriber.delete_subscription(subscription=subscription_name)
|
|
except NotFound:
|
|
self.logger.debug('Subscription %s not found', subscription_name)
|
|
|
|
def _message_callback(self, topic):
|
|
def callback(msg):
|
|
data = msg.data.decode()
|
|
try:
|
|
data = json.loads(data)
|
|
except Exception as e:
|
|
self.logger.debug('Not a valid JSON: %s: %s', data, e)
|
|
|
|
msg.ack()
|
|
self._bus.post(GooglePubsubMessageEvent(topic=topic, msg=data))
|
|
|
|
return callback
|
|
|
|
def main(self):
|
|
credentials = self.get_credentials(self.subscriber_audience)
|
|
with self._subscriber_lock:
|
|
self._subscriber = pubsub.SubscriberClient(credentials=credentials)
|
|
|
|
for topic in self.topics:
|
|
self.subscribe(topic=topic)
|
|
|
|
self.wait_stop()
|
|
with self._subscriber_lock:
|
|
self._close()
|
|
|
|
def _close(self):
|
|
with self._subscriber_lock:
|
|
if self._subscriber:
|
|
try:
|
|
self._subscriber.close()
|
|
except Exception as e:
|
|
self.logger.debug('Error while closing the subscriber: %s', e)
|
|
|
|
self._subscriber = None
|
|
|
|
def stop(self):
|
|
self._close()
|
|
super().stop()
|
|
|
|
|
|
# vim:sw=4:ts=4:et:
|