def client() -> PublisherClient:
if "PUBSUB_EMULATOR_HOST" not in os.environ:
client = PublisherClient(channel=grpc.insecure_channel(target=""))
else:
client = PublisherClient()
client._batch_class = AsyncioBatch
return client
def get_client(config: dict) -> PublisherClient:
"""Create a pubsub client."""
# Initialize PubSub client
timeout = config.get("PUBLISH_TIMEOUT_SECONDS", None)
client = PublisherClient()
client.api.publish = partial(
client.api.publish,
retry=Retry(TRANSIENT_ERRORS, deadline=timeout),
timeout=timeout,
)
client._batch_class = AsyncioBatch
return client
def init_app(app: Sanic) -> Tuple[PublisherClient, SQLiteAckQueue]:
"""Initialize Sanic app with url rules."""
# Initialize PubSub client
timeout = app.config.get("PUBLISH_TIMEOUT_SECONDS", None)
client = PublisherClient()
client.api.publish = partial(
client.api.publish,
retry=Retry(TRANSIENT_ERRORS, deadline=timeout),
timeout=timeout,
)
client._batch_class = AsyncioBatch
# Use a SQLiteAckQueue because:
# * we use acks to ensure messages only removed on success
# * persist-queue's SQLite*Queue is faster than its Queue
# * SQLite provides thread-safe and process-safe access
queue_config = {
key[6:].lower(): value
for key, value in app.config.items()
if key.startswith("QUEUE_")
}
q = SQLiteAckQueue(**queue_config)
# get metadata_headers config
metadata_headers = app.config["METADATA_HEADERS"]
# validate attribute keys
for attribute in metadata_headers.values():
if len(attribute.encode("utf8")) > 256:
# https://cloud.google.com/pubsub/quotas#resource_limits
raise ValueError("Metadata attribute exceeds key size limit of 256 bytes")
# generate one view_func per topic
handlers = {
route.topic: partial(
submit,
client=client,
q=q,
topic=route.topic,
metadata_headers=metadata_headers,
)
for route in app.config["ROUTE_TABLE"]
}
# add routes for ROUTE_TABLE
for route in app.config["ROUTE_TABLE"]:
app.add_route(
handler=handlers[route.topic],
uri=route.uri,
methods=[method.upper() for method in route.methods],
# required because handler.__name__ does not exist
# must be a unique name for each handler
name="submit_" + route.topic,
)
return client, q
