def start_subscriber(loop, topic):
client = SubscriberClient()
project_id = os.getenv('GCP_PROJECT')
topic_path = PublisherClient.topic_path(project_id, topic)
subscription_path = PublisherClient.subscription_path(project_id, topic)
# Create subscription if it doesn't already exist
try:
client.create_subscription(subscription_path, topic_path)
except google.api_core.exceptions.PermissionDenied as e:
raise TypeError('Please set the GCP_PROJECT environment variable') from e
# Subscribe to the subscription, receiving a Future that acts as a keepalive
keep_alive = client.subscribe(subscription_path, message_callback)
# Have the client run forever, pulling messages from this subscription,
# passing them to the specified callback function, and wrapping it in an
# asyncio task.
client.run_forever(keep_alive)
async def start_subscriber(topic):
client = SubscriberClient()
project_id = os.getenv("GCP_PROJECT")
topic_path = PublisherClient.topic_path(project_id, topic)
subscription_path = PublisherClient.subscription_path(project_id, topic)
# Create subscription if it doesn't already exist
try:
await client.create_subscription(subscription_path, topic_path)
except aiohttp.client_exceptions.ClientResponseError as e:
if e.status == 409: # Subscription exists
pass
else:
raise TypeError("Please set the GCP_PROJECT environment variable") from e
# For demo with Pub/Sub emulator, maybe ack_deadline_cache_timeout 300
# On GCP, default seems fine.
# For more options, check gcloud-aio docs:
# https://github.com/talkiq/gcloud-aio/tree/master/pubsub
await subscribe(subscription_path, message_callback, client, ack_deadline_cache_timeout=300)