Added sample for publishing/receiving messages with custom attributes…

… [(#1409)](GoogleCloudPlatform/python-docs-samples#1409)

samples/snippets/publisher.py

@@ -69,6 +69,23 @@ def publish_messages(project, topic_name):
     print('Published messages.')
 
 
+def publish_messages_with_custom_attributes(project, topic_name):
+    """Publishes multiple messages with custom attributes
+    to a Pub/Sub topic."""
+    publisher = pubsub_v1.PublisherClient()
+    topic_path = publisher.topic_path(project, topic_name)
+
+    for n in range(1, 10):
+        data = u'Message number {}'.format(n)
+        # Data must be a bytestring
+        data = data.encode('utf-8')
+        # Add two attributes, origin and username, to the message
+        publisher.publish(
+            topic_path, data, origin='python-sample', username='gcp')
+
+    print('Published messages with custom attributes.')
+
+
 def publish_messages_with_futures(project, topic_name):
     """Publishes multiple messages to a Pub/Sub topic and prints their
     message IDs."""
@@ -132,6 +149,11 @@ def publish_messages_with_batch_settings(project, topic_name):
         'publish', help=publish_messages.__doc__)
     publish_parser.add_argument('topic_name')
 
+    publish_with_custom_attributes_parser = subparsers.add_parser(
+        'publish-with-custom-attributes',
+        help=publish_messages_with_custom_attributes.__doc__)
+    publish_with_custom_attributes_parser.add_argument('topic_name')
+
     publish_with_futures_parser = subparsers.add_parser(
         'publish-with-futures',
         help=publish_messages_with_futures.__doc__)
@@ -152,6 +174,8 @@ def publish_messages_with_batch_settings(project, topic_name):
         delete_topic(args.project, args.topic_name)
     elif args.command == 'publish':
         publish_messages(args.project, args.topic_name)
+    elif args.command == 'publish-with-custom-attributes':
+        publish_messages_with_custom_attributes(args.project, args.topic_name)
     elif args.command == 'publish-with-futures':
         publish_messages_with_futures(args.project, args.topic_name)
     elif args.command == 'publish-with-batch-settings':

samples/snippets/publisher_test.py

@@ -81,6 +81,13 @@ def test_publish(topic, capsys):
     assert 'Published' in out
 
 
+def test_publish_with_custom_attributes(topic, capsys):
+    publisher.publish_messages_with_custom_attributes(PROJECT, TOPIC)
+
+    out, _ = capsys.readouterr()
+    assert 'Published' in out
+
+
 def test_publish_with_batch_settings(topic, capsys):
     publisher.publish_messages_with_batch_settings(PROJECT, TOPIC)
 

samples/snippets/subscriber.py

@@ -143,6 +143,30 @@ def callback(message):
         time.sleep(60)
 
 
+def receive_messages_with_custom_attributes(project, subscription_name):
+    """Receives messages from a pull subscription."""
+    subscriber = pubsub_v1.SubscriberClient()
+    subscription_path = subscriber.subscription_path(
+        project, subscription_name)
+
+    def callback(message):
+        print('Received message: {}'.format(message.data))
+        if message.attributes:
+            print('Attributes:')
+            for key in message.attributes:
+                value = message.attributes.get(key)
+                print('{}: {}'.format(key, value))
+        message.ack()
+
+    subscriber.subscribe(subscription_path, callback=callback)
+
+    # The subscriber is non-blocking, so we must keep the main thread from
+    # exiting to allow it to process messages in the background.
+    print('Listening for messages on {}'.format(subscription_path))
+    while True:
+        time.sleep(60)
+
+
 def receive_messages_with_flow_control(project, subscription_name):
     """Receives messages from a pull subscription with flow control."""
     subscriber = pubsub_v1.SubscriberClient()
@@ -227,6 +251,11 @@ def callback(message):
         'receive', help=receive_messages.__doc__)
     receive_parser.add_argument('subscription_name')
 
+    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_name')
+
     receive_with_flow_control_parser = subparsers.add_parser(
         'receive-flow-control',
         help=receive_messages_with_flow_control.__doc__)
@@ -259,6 +288,9 @@ def callback(message):
             args.project, args.subscription_name, args.endpoint)
     elif args.command == 'receive':
         receive_messages(args.project, args.subscription_name)
+    elif args.command == 'receive-custom-attributes':
+        receive_messages_with_custom_attributes(
+            args.project, args.subscription_name)
     elif args.command == 'receive-flow-control':
         receive_messages_with_flow_control(
             args.project, args.subscription_name)

samples/snippets/subscriber_test.py

@@ -129,6 +129,11 @@ def _publish_messages(publisher_client, topic):
             topic, data=data)
 
 
+def _publish_messages_with_custom_attributes(publisher_client, topic):
+    data = u'Test message'.encode('utf-8')
+    publisher_client.publish(topic, data=data, origin='python-sample')
+
+
 def _make_sleep_patch():
     real_sleep = time.sleep
 
@@ -155,6 +160,22 @@ def test_receive(publisher_client, topic, subscription, capsys):
     assert 'Message 1' in out
 
 
+def test_receive_with_custom_attributes(
+        publisher_client, topic, subscription, capsys):
+    _publish_messages_with_custom_attributes(publisher_client, topic)
+
+    with _make_sleep_patch():
+        with pytest.raises(RuntimeError, match='sigil'):
+            subscriber.receive_messages_with_custom_attributes(
+                PROJECT, SUBSCRIPTION)
+
+    out, _ = capsys.readouterr()
+    assert 'Test message' in out
+    assert 'Attributes' in out
+    assert 'origin' in out
+    assert 'python-sample' in out
+
+
 def test_receive_with_flow_control(
         publisher_client, topic, subscription, capsys):
     _publish_messages(publisher_client, topic)