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subscriber.py
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subscriber.py
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#!/usr/bin/env python
# Copyright 2016 Google Inc. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""This application demonstrates how to perform basic operations on
subscriptions with the Cloud Pub/Sub API.
For more information, see the README.md under /pubsub and the documentation
at https://cloud.google.com/pubsub/docs.
"""
import argparse
import typing
from typing import Optional
if typing.TYPE_CHECKING:
from google.pubsub_v1 import types as gapic_types
def list_subscriptions_in_topic(project_id: str, topic_id: str) -> None:
"""Lists all subscriptions for a given topic."""
# [START pubsub_list_topic_subscriptions]
from google.cloud import pubsub_v1
# TODO(developer)
# project_id = "your-project-id"
# topic_id = "your-topic-id"
publisher = pubsub_v1.PublisherClient()
topic_path = publisher.topic_path(project_id, topic_id)
response = publisher.list_topic_subscriptions(request={"topic": topic_path})
for subscription in response:
print(subscription)
# [END pubsub_list_topic_subscriptions]
def list_subscriptions_in_project(project_id: str) -> None:
"""Lists all subscriptions in the current project."""
# [START pubsub_list_subscriptions]
from google.cloud import pubsub_v1
# TODO(developer)
# project_id = "your-project-id"
subscriber = pubsub_v1.SubscriberClient()
project_path = f"projects/{project_id}"
# Wrap the subscriber in a 'with' block to automatically call close() to
# close the underlying gRPC channel when done.
with subscriber:
for subscription in subscriber.list_subscriptions(
request={"project": project_path}
):
print(subscription.name)
# [END pubsub_list_subscriptions]
def create_subscription(project_id: str, topic_id: str, subscription_id: str) -> None:
"""Create a new pull subscription on the given topic."""
# [START pubsub_create_pull_subscription]
from google.cloud import pubsub_v1
# TODO(developer)
# project_id = "your-project-id"
# topic_id = "your-topic-id"
# subscription_id = "your-subscription-id"
publisher = pubsub_v1.PublisherClient()
subscriber = pubsub_v1.SubscriberClient()
topic_path = publisher.topic_path(project_id, topic_id)
subscription_path = subscriber.subscription_path(project_id, subscription_id)
# Wrap the subscriber in a 'with' block to automatically call close() to
# close the underlying gRPC channel when done.
with subscriber:
subscription = subscriber.create_subscription(
request={"name": subscription_path, "topic": topic_path}
)
print(f"Subscription created: {subscription}")
# [END pubsub_create_pull_subscription]
def create_subscription_with_dead_letter_topic(
project_id: str,
topic_id: str,
subscription_id: str,
dead_letter_topic_id: str,
max_delivery_attempts: int = 5,
) -> None:
"""Create a subscription with dead letter policy."""
# [START pubsub_dead_letter_create_subscription]
from google.cloud import pubsub_v1
from google.cloud.pubsub_v1.types import DeadLetterPolicy
# TODO(developer)
# project_id = "your-project-id"
# endpoint = "https://my-test-project.appspot.com/push"
# TODO(developer): This is an existing topic that the subscription
# with dead letter policy is attached to.
# topic_id = "your-topic-id"
# TODO(developer): This is an existing subscription with a dead letter policy.
# subscription_id = "your-subscription-id"
# TODO(developer): This is an existing dead letter topic that the subscription
# with dead letter policy will forward dead letter messages to.
# dead_letter_topic_id = "your-dead-letter-topic-id"
# TODO(developer): This is the maximum number of delivery attempts allowed
# for a message before it gets delivered to a dead letter topic.
# max_delivery_attempts = 5
publisher = pubsub_v1.PublisherClient()
subscriber = pubsub_v1.SubscriberClient()
topic_path = publisher.topic_path(project_id, topic_id)
subscription_path = subscriber.subscription_path(project_id, subscription_id)
dead_letter_topic_path = publisher.topic_path(project_id, dead_letter_topic_id)
dead_letter_policy = DeadLetterPolicy(
dead_letter_topic=dead_letter_topic_path,
max_delivery_attempts=max_delivery_attempts,
)
with subscriber:
request = {
"name": subscription_path,
"topic": topic_path,
"dead_letter_policy": dead_letter_policy,
}
subscription = subscriber.create_subscription(request)
print(f"Subscription created: {subscription.name}")
print(
f"It will forward dead letter messages to: {subscription.dead_letter_policy.dead_letter_topic}."
)
print(
f"After {subscription.dead_letter_policy.max_delivery_attempts} delivery attempts."
)
# [END pubsub_dead_letter_create_subscription]
def create_push_subscription(
project_id: str, topic_id: str, subscription_id: str, endpoint: str
) -> None:
"""Create a new push subscription on the given topic."""
# [START pubsub_create_push_subscription]
from google.cloud import pubsub_v1
# TODO(developer)
# project_id = "your-project-id"
# topic_id = "your-topic-id"
# subscription_id = "your-subscription-id"
# endpoint = "https://my-test-project.appspot.com/push"
publisher = pubsub_v1.PublisherClient()
subscriber = pubsub_v1.SubscriberClient()
topic_path = publisher.topic_path(project_id, topic_id)
subscription_path = subscriber.subscription_path(project_id, subscription_id)
push_config = pubsub_v1.types.PushConfig(push_endpoint=endpoint)
# Wrap the subscriber in a 'with' block to automatically call close() to
# close the underlying gRPC channel when done.
with subscriber:
subscription = subscriber.create_subscription(
request={
"name": subscription_path,
"topic": topic_path,
"push_config": push_config,
}
)
print(f"Push subscription created: {subscription}.")
print(f"Endpoint for subscription is: {endpoint}")
# [END pubsub_create_push_subscription]
def create_subscription_with_ordering(
project_id: str, topic_id: str, subscription_id: str
) -> None:
"""Create a subscription with ordering enabled."""
# [START pubsub_enable_subscription_ordering]
from google.cloud import pubsub_v1
# TODO(developer): Choose an existing topic.
# project_id = "your-project-id"
# topic_id = "your-topic-id"
# subscription_id = "your-subscription-id"
publisher = pubsub_v1.PublisherClient()
subscriber = pubsub_v1.SubscriberClient()
topic_path = publisher.topic_path(project_id, topic_id)
subscription_path = subscriber.subscription_path(project_id, subscription_id)
with subscriber:
subscription = subscriber.create_subscription(
request={
"name": subscription_path,
"topic": topic_path,
"enable_message_ordering": True,
}
)
print(f"Created subscription with ordering: {subscription}")
# [END pubsub_enable_subscription_ordering]
def create_subscription_with_filtering(
project_id: str, topic_id: str, subscription_id: str, filter: str,
) -> None:
"""Create a subscription with filtering enabled."""
# [START pubsub_create_subscription_with_filter]
from google.cloud import pubsub_v1
# TODO(developer): Choose an existing topic.
# project_id = "your-project-id"
# topic_id = "your-topic-id"
# subscription_id = "your-subscription-id"
# filter = "attributes.author=\"unknown\""
publisher = pubsub_v1.PublisherClient()
subscriber = pubsub_v1.SubscriberClient()
topic_path = publisher.topic_path(project_id, topic_id)
subscription_path = subscriber.subscription_path(project_id, subscription_id)
with subscriber:
subscription = subscriber.create_subscription(
request={"name": subscription_path, "topic": topic_path, "filter": filter}
)
print(f"Created subscription with filtering enabled: {subscription}")
# [END pubsub_create_subscription_with_filter]
def delete_subscription(project_id: str, subscription_id: str) -> None:
"""Deletes an existing Pub/Sub topic."""
# [START pubsub_delete_subscription]
from google.cloud import pubsub_v1
# TODO(developer)
# project_id = "your-project-id"
# subscription_id = "your-subscription-id"
subscriber = pubsub_v1.SubscriberClient()
subscription_path = subscriber.subscription_path(project_id, subscription_id)
# Wrap the subscriber in a 'with' block to automatically call close() to
# close the underlying gRPC channel when done.
with subscriber:
subscriber.delete_subscription(request={"subscription": subscription_path})
print(f"Subscription deleted: {subscription_path}.")
# [END pubsub_delete_subscription]
def update_push_subscription(
project_id: str, topic_id: str, subscription_id: str, endpoint: str
) -> None:
"""
Updates an existing Pub/Sub subscription's push endpoint URL.
Note that certain properties of a subscription, such as
its topic, are not modifiable.
"""
# [START pubsub_update_push_configuration]
from google.cloud import pubsub_v1
# TODO(developer)
# project_id = "your-project-id"
# topic_id = "your-topic-id"
# subscription_id = "your-subscription-id"
# endpoint = "https://my-test-project.appspot.com/push"
subscriber = pubsub_v1.SubscriberClient()
subscription_path = subscriber.subscription_path(project_id, subscription_id)
push_config = pubsub_v1.types.PushConfig(push_endpoint=endpoint)
subscription = pubsub_v1.types.Subscription(
name=subscription_path, topic=topic_id, push_config=push_config
)
update_mask = {"paths": {"push_config"}}
# Wrap the subscriber in a 'with' block to automatically call close() to
# close the underlying gRPC channel when done.
with subscriber:
result = subscriber.update_subscription(
request={"subscription": subscription, "update_mask": update_mask}
)
print(f"Subscription updated: {subscription_path}")
print(f"New endpoint for subscription is: {result.push_config}.")
# [END pubsub_update_push_configuration]
def update_subscription_with_dead_letter_policy(
project_id: str,
topic_id: str,
subscription_id: str,
dead_letter_topic_id: str,
max_delivery_attempts: int = 5,
) -> "gapic_types.Subscription":
"""Update a subscription's dead letter policy."""
# [START pubsub_dead_letter_update_subscription]
from google.cloud import pubsub_v1
from google.cloud.pubsub_v1.types import DeadLetterPolicy, FieldMask
# TODO(developer)
# project_id = "your-project-id"
# TODO(developer): This is an existing topic that the subscription
# with dead letter policy is attached to.
# topic_id = "your-topic-id"
# TODO(developer): This is an existing subscription with a dead letter policy.
# subscription_id = "your-subscription-id"
# TODO(developer): This is an existing dead letter topic that the subscription
# with dead letter policy will forward dead letter messages to.
# dead_letter_topic_id = "your-dead-letter-topic-id"
# TODO(developer): This is the maximum number of delivery attempts allowed
# for a message before it gets delivered to a dead letter topic.
# max_delivery_attempts = 5
publisher = pubsub_v1.PublisherClient()
subscriber = pubsub_v1.SubscriberClient()
topic_path = publisher.topic_path(project_id, topic_id)
subscription_path = subscriber.subscription_path(project_id, subscription_id)
dead_letter_topic_path = publisher.topic_path(project_id, dead_letter_topic_id)
subscription_before_update = subscriber.get_subscription(
request={"subscription": subscription_path}
)
print(f"Before the update: {subscription_before_update}.")
# Indicates which fields in the provided subscription to update.
update_mask = FieldMask(paths=["dead_letter_policy"])
# Construct a dead letter policy you expect to have after the update.
dead_letter_policy = DeadLetterPolicy(
dead_letter_topic=dead_letter_topic_path,
max_delivery_attempts=max_delivery_attempts,
)
# Construct the subscription with the dead letter policy you expect to have
# after the update. Here, values in the required fields (name, topic) help
# identify the subscription.
subscription = pubsub_v1.types.Subscription(
name=subscription_path, topic=topic_path, dead_letter_policy=dead_letter_policy,
)
with subscriber:
subscription_after_update = subscriber.update_subscription(
request={"subscription": subscription, "update_mask": update_mask}
)
print(f"After the update: {subscription_after_update}.")
# [END pubsub_dead_letter_update_subscription]
return subscription_after_update
def remove_dead_letter_policy(
project_id: str, topic_id: str, subscription_id: str
) -> "gapic_types.Subscription":
"""Remove dead letter policy from a subscription."""
# [START pubsub_dead_letter_remove]
from google.cloud import pubsub_v1
from google.cloud.pubsub_v1.types import FieldMask
# TODO(developer)
# project_id = "your-project-id"
# TODO(developer): This is an existing topic that the subscription
# with dead letter policy is attached to.
# topic_id = "your-topic-id"
# TODO(developer): This is an existing subscription with a dead letter policy.
# subscription_id = "your-subscription-id"
publisher = pubsub_v1.PublisherClient()
subscriber = pubsub_v1.SubscriberClient()
topic_path = publisher.topic_path(project_id, topic_id)
subscription_path = subscriber.subscription_path(project_id, subscription_id)
subscription_before_update = subscriber.get_subscription(
request={"subscription": subscription_path}
)
print(f"Before removing the policy: {subscription_before_update}.")
# Indicates which fields in the provided subscription to update.
update_mask = FieldMask(paths=["dead_letter_policy"])
# Construct the subscription (without any dead letter policy) that you
# expect to have after the update.
subscription = pubsub_v1.types.Subscription(
name=subscription_path, topic=topic_path
)
with subscriber:
subscription_after_update = subscriber.update_subscription(
request={"subscription": subscription, "update_mask": update_mask}
)
print(f"After removing the policy: {subscription_after_update}.")
# [END pubsub_dead_letter_remove]
return subscription_after_update
def receive_messages(
project_id: str, subscription_id: str, timeout: Optional[float] = None
) -> None:
"""Receives messages from a pull subscription."""
# [START pubsub_subscriber_async_pull]
# [START pubsub_quickstart_subscriber]
from concurrent.futures import TimeoutError
from google.cloud import pubsub_v1
# TODO(developer)
# project_id = "your-project-id"
# subscription_id = "your-subscription-id"
# Number of seconds the subscriber should listen for messages
# timeout = 5.0
subscriber = pubsub_v1.SubscriberClient()
# The `subscription_path` method creates a fully qualified identifier
# in the form `projects/{project_id}/subscriptions/{subscription_id}`
subscription_path = subscriber.subscription_path(project_id, subscription_id)
def callback(message: pubsub_v1.subscriber.message.Message) -> None:
print(f"Received {message}.")
message.ack()
streaming_pull_future = subscriber.subscribe(subscription_path, callback=callback)
print(f"Listening for messages on {subscription_path}..\n")
# Wrap subscriber in a 'with' block to automatically call close() when done.
with subscriber:
try:
# When `timeout` is not set, result() will block indefinitely,
# unless an exception is encountered first.
streaming_pull_future.result(timeout=timeout)
except TimeoutError:
streaming_pull_future.cancel() # Trigger the shutdown.
streaming_pull_future.result() # Block until the shutdown is complete.
# [END pubsub_subscriber_async_pull]
# [END pubsub_quickstart_subscriber]
def receive_messages_with_custom_attributes(
project_id: str, subscription_id: str, timeout: Optional[float] = None
) -> None:
"""Receives messages from a pull subscription."""
# [START pubsub_subscriber_async_pull_custom_attributes]
from concurrent.futures import TimeoutError
from google.cloud import pubsub_v1
# TODO(developer)
# project_id = "your-project-id"
# subscription_id = "your-subscription-id"
# Number of seconds the subscriber should listen for messages
# timeout = 5.0
subscriber = pubsub_v1.SubscriberClient()
subscription_path = subscriber.subscription_path(project_id, subscription_id)
def callback(message: pubsub_v1.subscriber.message.Message) -> None:
print(f"Received {message.data!r}.")
if message.attributes:
print("Attributes:")
for key in message.attributes:
value = message.attributes.get(key)
print(f"{key}: {value}")
message.ack()
streaming_pull_future = subscriber.subscribe(subscription_path, callback=callback)
print(f"Listening for messages on {subscription_path}..\n")
# Wrap subscriber in a 'with' block to automatically call close() when done.
with subscriber:
try:
# When `timeout` is not set, result() will block indefinitely,
# unless an exception is encountered first.
streaming_pull_future.result(timeout=timeout)
except TimeoutError:
streaming_pull_future.cancel() # Trigger the shutdown.
streaming_pull_future.result() # Block until the shutdown is complete.
# [END pubsub_subscriber_async_pull_custom_attributes]
def receive_messages_with_flow_control(
project_id: str, subscription_id: str, timeout: Optional[float] = None
) -> None:
"""Receives messages from a pull subscription with flow control."""
# [START pubsub_subscriber_flow_settings]
from concurrent.futures import TimeoutError
from google.cloud import pubsub_v1
# TODO(developer)
# project_id = "your-project-id"
# subscription_id = "your-subscription-id"
# Number of seconds the subscriber should listen for messages
# timeout = 5.0
subscriber = pubsub_v1.SubscriberClient()
subscription_path = subscriber.subscription_path(project_id, subscription_id)
def callback(message: pubsub_v1.subscriber.message.Message) -> None:
print(f"Received {message.data!r}.")
message.ack()
# Limit the subscriber to only have ten outstanding messages at a time.
flow_control = pubsub_v1.types.FlowControl(max_messages=10)
streaming_pull_future = subscriber.subscribe(
subscription_path, callback=callback, flow_control=flow_control
)
print(f"Listening for messages on {subscription_path}..\n")
# Wrap subscriber in a 'with' block to automatically call close() when done.
with subscriber:
try:
# When `timeout` is not set, result() will block indefinitely,
# unless an exception is encountered first.
streaming_pull_future.result(timeout=timeout)
except TimeoutError:
streaming_pull_future.cancel() # Trigger the shutdown.
streaming_pull_future.result() # Block until the shutdown is complete.
# [END pubsub_subscriber_flow_settings]
def receive_messages_with_blocking_shutdown(
project_id: str, subscription_id: str, timeout: float = 5.0
) -> None:
"""Shuts down a pull subscription by awaiting message callbacks to complete."""
# [START pubsub_subscriber_blocking_shutdown]
import time
from concurrent.futures import TimeoutError
from google.cloud import pubsub_v1
# TODO(developer)
# project_id = "your-project-id"
# subscription_id = "your-subscription-id"
# Number of seconds the subscriber should listen for messages
# timeout = 5.0
subscriber = pubsub_v1.SubscriberClient()
subscription_path = subscriber.subscription_path(project_id, subscription_id)
def callback(message: pubsub_v1.subscriber.message.Message) -> None:
print(f"Received {message.data!r}.")
time.sleep(timeout + 3.0) # Pocess longer than streaming pull future timeout.
message.ack()
print(f"Done processing the message {message.data!r}.")
streaming_pull_future = subscriber.subscribe(
subscription_path, callback=callback, await_callbacks_on_shutdown=True,
)
print(f"Listening for messages on {subscription_path}..\n")
# Wrap subscriber in a 'with' block to automatically call close() when done.
with subscriber:
try:
# When `timeout` is not set, result() will block indefinitely,
# unless an exception is encountered first.
streaming_pull_future.result(timeout=timeout)
except TimeoutError:
streaming_pull_future.cancel()
print("Streaming pull future canceled.")
streaming_pull_future.result() # Blocks until shutdown complete.
print("Done waiting for the stream shutdown.")
# The "Done waiting..." message is only printed *after* the processing of all
# received messages has completed.
# [END pubsub_subscriber_blocking_shutdown]
def receive_messages_with_exactly_once_subscribe(
project_id: str, subscription_id: str, timeout: Optional[float] = None
) -> None:
"""Receives messages from a pull subscription with exactly-once delivery enabled."""
# [START pubsub_subscriber_pull_with_exactly_once_delivery_enabled]
from concurrent.futures import TimeoutError
from google.cloud import pubsub_v1
from google.cloud.pubsub_v1.subscriber import sub_exceptions
# TODO(developer)
# project_id = "your-project-id"
# subscription_id = "your-subscription-id"
# Number of seconds the subscriber should listen for messages
# timeout = 5.0
subscriber = pubsub_v1.SubscriberClient()
# The `subscription_path` method creates a fully qualified identifier
# in the form `projects/{project_id}/subscriptions/{subscription_id}`
subscription_path = subscriber.subscription_path(project_id, subscription_id)
def callback(message: pubsub_v1.subscriber.message.Message) -> None:
print(f"Received {message}.")
ack_future = message.ack_with_response()
try:
# Block on result of acknowledge call.
ack_future.result()
print(f"Ack for message {message.message_id} successful.")
except sub_exceptions.AcknowledgeError as e:
print(
f"Ack for message {message.message_id} failed with error: {e.error_code}"
)
streaming_pull_future = subscriber.subscribe(subscription_path, callback=callback)
print(f"Listening for messages on {subscription_path}..\n")
# Wrap subscriber in a 'with' block to automatically call close() when done.
with subscriber:
try:
# When `timeout` is not set, result() will block indefinitely,
# unless an exception is encountered first.
streaming_pull_future.result(timeout=timeout)
except TimeoutError:
streaming_pull_future.cancel() # Trigger the shutdown.
streaming_pull_future.result() # Block until the shutdown is complete.
# [END pubsub_subscriber_pull_with_exactly_once_delivery_enabled]
def synchronous_pull(project_id: str, subscription_id: str) -> None:
"""Pulling messages synchronously."""
# [START pubsub_subscriber_sync_pull]
from google.api_core import retry
from google.cloud import pubsub_v1
# TODO(developer)
# project_id = "your-project-id"
# subscription_id = "your-subscription-id"
subscriber = pubsub_v1.SubscriberClient()
subscription_path = subscriber.subscription_path(project_id, subscription_id)
NUM_MESSAGES = 3
# Wrap the subscriber in a 'with' block to automatically call close() to
# close the underlying gRPC channel when done.
with subscriber:
# The subscriber pulls a specific number of messages. The actual
# number of messages pulled may be smaller than max_messages.
response = subscriber.pull(
request={"subscription": subscription_path, "max_messages": NUM_MESSAGES},
retry=retry.Retry(deadline=300),
)
if len(response.received_messages) == 0:
return
ack_ids = []
for received_message in response.received_messages:
print(f"Received: {received_message.message.data}.")
ack_ids.append(received_message.ack_id)
# Acknowledges the received messages so they will not be sent again.
subscriber.acknowledge(
request={"subscription": subscription_path, "ack_ids": ack_ids}
)
print(
f"Received and acknowledged {len(response.received_messages)} messages from {subscription_path}."
)
# [END pubsub_subscriber_sync_pull]
def synchronous_pull_with_lease_management(
project_id: str, subscription_id: str
) -> None:
"""Pulling messages synchronously with lease management"""
# [START pubsub_subscriber_sync_pull_with_lease]
import logging
import multiprocessing
import sys
import time
from google.api_core import retry
from google.cloud import pubsub_v1
multiprocessing.log_to_stderr()
logger = multiprocessing.get_logger()
logger.setLevel(logging.INFO)
processes = dict()
# TODO(developer)
# project_id = "your-project-id"
# subscription_id = "your-subscription-id"
subscriber = pubsub_v1.SubscriberClient()
subscription_path = subscriber.subscription_path(project_id, subscription_id)
response = subscriber.pull(
request={"subscription": subscription_path, "max_messages": 3},
retry=retry.Retry(deadline=300),
)
if len(response.received_messages) == 0:
return
# Start a process for each message based on its size modulo 10.
for message in response.received_messages:
process = multiprocessing.Process(
target=time.sleep, args=(sys.getsizeof(message) % 10,)
)
processes[process] = (message.ack_id, message.message.data)
process.start()
while processes:
# Take a break every second.
if processes:
time.sleep(1)
for process in list(processes):
ack_id, msg_data = processes[process]
# If the process is running, reset the ack deadline.
if process.is_alive():
subscriber.modify_ack_deadline(
request={
"subscription": subscription_path,
"ack_ids": [ack_id],
# Must be between 10 and 600.
"ack_deadline_seconds": 15,
}
)
logger.info(f"Reset ack deadline for {msg_data}.")
# If the process is complete, acknowledge the message.
else:
subscriber.acknowledge(
request={"subscription": subscription_path, "ack_ids": [ack_id]}
)
logger.info(f"Acknowledged {msg_data}.")
processes.pop(process)
print(
f"Received and acknowledged {len(response.received_messages)} messages from {subscription_path}."
)
# Close the underlying gPRC channel. Alternatively, wrap subscriber in
# a 'with' block to automatically call close() when done.
subscriber.close()
# [END pubsub_subscriber_sync_pull_with_lease]
def listen_for_errors(
project_id: str, subscription_id: str, timeout: Optional[float] = None
) -> None:
"""Receives messages and catches errors from a pull subscription."""
# [START pubsub_subscriber_error_listener]
from google.cloud import pubsub_v1
# TODO(developer)
# project_id = "your-project-id"
# subscription_id = "your-subscription-id"
# Number of seconds the subscriber should listen for messages
# timeout = 5.0
subscriber = pubsub_v1.SubscriberClient()
subscription_path = subscriber.subscription_path(project_id, subscription_id)
def callback(message: pubsub_v1.subscriber.message.Message) -> None:
print(f"Received {message}.")
message.ack()
streaming_pull_future = subscriber.subscribe(subscription_path, callback=callback)
print(f"Listening for messages on {subscription_path}..\n")
# Wrap subscriber in a 'with' block to automatically call close() when done.
with subscriber:
# When `timeout` is not set, result() will block indefinitely,
# unless an exception is encountered first.
try:
streaming_pull_future.result(timeout=timeout)
except Exception as e:
print(
f"Listening for messages on {subscription_path} threw an exception: {e}."
)
streaming_pull_future.cancel() # Trigger the shutdown.
streaming_pull_future.result() # Block until the shutdown is complete.
# [END pubsub_subscriber_error_listener]
def receive_messages_with_delivery_attempts(
project_id: str, subscription_id: str, timeout: Optional[float] = None
) -> None:
# [START pubsub_dead_letter_delivery_attempt]
from concurrent.futures import TimeoutError
from google.cloud import pubsub_v1
# TODO(developer)
# project_id = "your-project-id"
# subscription_id = "your-subscription-id"
subscriber = pubsub_v1.SubscriberClient()
subscription_path = subscriber.subscription_path(project_id, subscription_id)
def callback(message: pubsub_v1.subscriber.message.Message) -> None:
print(f"Received {message}.")
print(f"With delivery attempts: {message.delivery_attempt}.")
message.ack()
streaming_pull_future = subscriber.subscribe(subscription_path, callback=callback)
print(f"Listening for messages on {subscription_path}..\n")
# Wrap subscriber in a 'with' block to automatically call close() when done.
with subscriber:
# When `timeout` is not set, result() will block indefinitely,
# unless an exception is encountered first.
try:
streaming_pull_future.result(timeout=timeout)
except TimeoutError:
streaming_pull_future.cancel() # Trigger the shutdown.
streaming_pull_future.result() # Block until the shutdown is complete.
# [END pubsub_dead_letter_delivery_attempt]
if __name__ == "__main__": # noqa
parser = argparse.ArgumentParser(
description=__doc__, formatter_class=argparse.RawDescriptionHelpFormatter,
)
parser.add_argument("project_id", help="Your Google Cloud project ID")
subparsers = parser.add_subparsers(dest="command")
list_in_topic_parser = subparsers.add_parser(
"list-in-topic", help=list_subscriptions_in_topic.__doc__
)
list_in_topic_parser.add_argument("topic_id")
list_in_project_parser = subparsers.add_parser(
"list-in-project", help=list_subscriptions_in_project.__doc__
)
create_parser = subparsers.add_parser("create", help=create_subscription.__doc__)
create_parser.add_argument("topic_id")
create_parser.add_argument("subscription_id")
create_with_dead_letter_policy_parser = subparsers.add_parser(
"create-with-dead-letter-policy",
help=create_subscription_with_dead_letter_topic.__doc__,
)
create_with_dead_letter_policy_parser.add_argument("topic_id")
create_with_dead_letter_policy_parser.add_argument("subscription_id")
create_with_dead_letter_policy_parser.add_argument("dead_letter_topic_id")
create_with_dead_letter_policy_parser.add_argument(
"max_delivery_attempts", type=int, nargs="?", default=5
)
create_push_parser = subparsers.add_parser(
"create-push", help=create_push_subscription.__doc__
)
create_push_parser.add_argument("topic_id")
create_push_parser.add_argument("subscription_id")
create_push_parser.add_argument("endpoint")
create_subscription_with_ordering_parser = subparsers.add_parser(
"create-with-ordering", help=create_subscription_with_ordering.__doc__
)
create_subscription_with_ordering_parser.add_argument("topic_id")
create_subscription_with_ordering_parser.add_argument("subscription_id")
create_subscription_with_filtering_parser = subparsers.add_parser(
"create-with-filtering", help=create_subscription_with_filtering.__doc__
)
create_subscription_with_filtering_parser.add_argument("topic_id")
create_subscription_with_filtering_parser.add_argument("subscription_id")
create_subscription_with_filtering_parser.add_argument("filter")
delete_parser = subparsers.add_parser("delete", help=delete_subscription.__doc__)
delete_parser.add_argument("subscription_id")
update_push_parser = subparsers.add_parser(
"update-push", help=update_push_subscription.__doc__
)
update_push_parser.add_argument("topic_id")
update_push_parser.add_argument("subscription_id")
update_push_parser.add_argument("endpoint")
update_dead_letter_policy_parser = subparsers.add_parser(
"update-dead-letter-policy",
help=update_subscription_with_dead_letter_policy.__doc__,
)
update_dead_letter_policy_parser.add_argument("topic_id")
update_dead_letter_policy_parser.add_argument("subscription_id")
update_dead_letter_policy_parser.add_argument("dead_letter_topic_id")
update_dead_letter_policy_parser.add_argument(
"max_delivery_attempts", type=int, nargs="?", default=5
)
remove_dead_letter_policy_parser = subparsers.add_parser(
"remove-dead-letter-policy", help=remove_dead_letter_policy.__doc__
)
remove_dead_letter_policy_parser.add_argument("topic_id")
remove_dead_letter_policy_parser.add_argument("subscription_id")
receive_parser = subparsers.add_parser("receive", help=receive_messages.__doc__)
receive_parser.add_argument("subscription_id")
receive_parser.add_argument("timeout", default=None, type=float, nargs="?")
receive_with_custom_attributes_parser = subparsers.add_parser(
"receive-custom-attributes",
help=receive_messages_with_custom_attributes.__doc__,
)
receive_with_custom_attributes_parser.add_argument("subscription_id")
receive_with_custom_attributes_parser.add_argument(
"timeout", default=None, type=float, nargs="?"
)
receive_with_flow_control_parser = subparsers.add_parser(
"receive-flow-control", help=receive_messages_with_flow_control.__doc__
)
receive_with_flow_control_parser.add_argument("subscription_id")
receive_with_flow_control_parser.add_argument(
"timeout", default=None, type=float, nargs="?"
)
receive_with_blocking_shutdown_parser = subparsers.add_parser(
"receive-blocking-shutdown",
help=receive_messages_with_blocking_shutdown.__doc__,
)
receive_with_blocking_shutdown_parser.add_argument("subscription_id")
receive_with_blocking_shutdown_parser.add_argument(
"timeout", default=None, type=float, nargs="?"
)
synchronous_pull_parser = subparsers.add_parser(
"receive-synchronously", help=synchronous_pull.__doc__
)
synchronous_pull_parser.add_argument("subscription_id")
synchronous_pull_with_lease_management_parser = subparsers.add_parser(
"receive-synchronously-with-lease",
help=synchronous_pull_with_lease_management.__doc__,
)
synchronous_pull_with_lease_management_parser.add_argument("subscription_id")
listen_for_errors_parser = subparsers.add_parser(
"listen-for-errors", help=listen_for_errors.__doc__
)
listen_for_errors_parser.add_argument("subscription_id")
listen_for_errors_parser.add_argument(
"timeout", default=None, type=float, nargs="?"
)
receive_messages_with_delivery_attempts_parser = subparsers.add_parser(
"receive-messages-with-delivery-attempts",
help=receive_messages_with_delivery_attempts.__doc__,
)
receive_messages_with_delivery_attempts_parser.add_argument("subscription_id")
receive_messages_with_delivery_attempts_parser.add_argument(
"timeout", default=None, type=float, nargs="?"
)
args = parser.parse_args()
if args.command == "list-in-topic":
list_subscriptions_in_topic(args.project_id, args.topic_id)
elif args.command == "list-in-project":
list_subscriptions_in_project(args.project_id)
elif args.command == "create":
create_subscription(args.project_id, args.topic_id, args.subscription_id)
elif args.command == "create-with-dead-letter-policy":
create_subscription_with_dead_letter_topic(
args.project_id,
args.topic_id,
args.subscription_id,
args.dead_letter_topic_id,
args.max_delivery_attempts,
)
elif args.command == "create-push":
create_push_subscription(
args.project_id, args.topic_id, args.subscription_id, args.endpoint
)
elif args.command == "create-with-ordering":
create_subscription_with_ordering(
args.project_id, args.topic_id, args.subscription_id
)
elif args.command == "create-with-filtering":
create_subscription_with_filtering(
args.project_id, args.topic_id, args.subscription_id, args.filter
)
elif args.command == "delete":
delete_subscription(args.project_id, args.subscription_id)
elif args.command == "update-push":
update_push_subscription(
args.project_id, args.topic_id, args.subscription_id, args.endpoint
)
elif args.command == "update-dead-letter-policy":
update_subscription_with_dead_letter_policy(
args.project_id,
args.topic_id,
args.subscription_id,
args.dead_letter_topic_id,