samples: add subscription detachment sample

samples/snippets/README.rst

@@ -225,8 +225,8 @@ To run this sample:
     $ python iam.py
 
     usage: iam.py [-h]
-                  project
-                  {get-topic-policy,get-subscription-policy,set-topic-policy,set-subscription-policy,check-topic-permissions,check-subscription-permissions}
+                  project_id
+                  {get-topic-policy,get-subscription-policy,set-topic-policy,set-subscription-policy,check-topic-permissions,check-subscription-permissions,detach-subscription}
                   ...
 
     This application demonstrates how to perform basic operations on IAM
@@ -236,8 +236,8 @@ To run this sample:
     at https://cloud.google.com/pubsub/docs.
 
     positional arguments:
-      project               Your Google Cloud project ID
-      {get-topic-policy,get-subscription-policy,set-topic-policy,set-subscription-policy,check-topic-permissions,check-subscription-permissions}
+      project_id            Your Google Cloud project ID
+      {get-topic-policy,get-subscription-policy,set-topic-policy,set-subscription-policy,check-topic-permissions,check-subscription-permissions,detach-subscription}
         get-topic-policy    Prints the IAM policy for the given topic.
         get-subscription-policy
                             Prints the IAM policy for the given subscription.
@@ -250,6 +250,9 @@ To run this sample:
         check-subscription-permissions
                             Checks to which permissions are available on the given
                             subscription.
+        detach-subscription
+                            Detaches a subscription from a topic and drop all
+                            messages retained in it.
 
     optional arguments:
       -h, --help            show this help message and exit
@@ -273,4 +276,4 @@ to `browse the source`_ and  `report issues`_.
     https://github.com/GoogleCloudPlatform/google-cloud-python/issues
 
 
-.. _Google Cloud SDK: https://cloud.google.com/sdk/
+.. _Google Cloud SDK: https://cloud.google.com/sdk/

samples/snippets/iam.py

@@ -24,17 +24,17 @@
 import argparse
 
 
-def get_topic_policy(project, topic_id):
+def get_topic_policy(project_id, topic_id):
     """Prints the IAM policy for the given topic."""
     # [START pubsub_get_topic_policy]
     from google.cloud import pubsub_v1
 
-    # TODO(developer)
+    # TODO(developer): Choose an existing topic.
     # project_id = "your-project-id"
     # topic_id = "your-topic-id"
 
     client = pubsub_v1.PublisherClient()
-    topic_path = client.topic_path(project, topic_id)
+    topic_path = client.topic_path(project_id, topic_id)
 
     policy = client.get_iam_policy(topic_path)
 
@@ -44,17 +44,17 @@ def get_topic_policy(project, topic_id):
     # [END pubsub_get_topic_policy]
 
 
-def get_subscription_policy(project, subscription_id):
+def get_subscription_policy(project_id, subscription_id):
     """Prints the IAM policy for the given subscription."""
     # [START pubsub_get_subscription_policy]
     from google.cloud import pubsub_v1
 
-    # TODO(developer)
+    # TODO(developer): Choose an existing subscription.
     # project_id = "your-project-id"
     # subscription_id = "your-subscription-id"
 
     client = pubsub_v1.SubscriberClient()
-    subscription_path = client.subscription_path(project, subscription_id)
+    subscription_path = client.subscription_path(project_id, subscription_id)
 
     policy = client.get_iam_policy(subscription_path)
 
@@ -66,17 +66,17 @@ def get_subscription_policy(project, subscription_id):
     # [END pubsub_get_subscription_policy]
 
 
-def set_topic_policy(project, topic_id):
+def set_topic_policy(project_id, topic_id):
     """Sets the IAM policy for a topic."""
     # [START pubsub_set_topic_policy]
     from google.cloud import pubsub_v1
 
-    # TODO(developer)
+    # TODO(developer): Choose an existing topic.
     # project_id = "your-project-id"
     # topic_id = "your-topic-id"
 
     client = pubsub_v1.PublisherClient()
-    topic_path = client.topic_path(project, topic_id)
+    topic_path = client.topic_path(project_id, topic_id)
 
     policy = client.get_iam_policy(topic_path)
 
@@ -95,17 +95,17 @@ def set_topic_policy(project, topic_id):
     # [END pubsub_set_topic_policy]
 
 
-def set_subscription_policy(project, subscription_id):
+def set_subscription_policy(project_id, subscription_id):
     """Sets the IAM policy for a topic."""
     # [START pubsub_set_subscription_policy]
     from google.cloud import pubsub_v1
 
-    # TODO(developer)
+    # TODO(developer): Choose an existing subscription.
     # project_id = "your-project-id"
     # subscription_id = "your-subscription-id"
 
     client = pubsub_v1.SubscriberClient()
-    subscription_path = client.subscription_path(project, subscription_id)
+    subscription_path = client.subscription_path(project_id, subscription_id)
 
     policy = client.get_iam_policy(subscription_path)
 
@@ -124,17 +124,17 @@ def set_subscription_policy(project, subscription_id):
     # [END pubsub_set_subscription_policy]
 
 
-def check_topic_permissions(project, topic_id):
+def check_topic_permissions(project_id, topic_id):
     """Checks to which permissions are available on the given topic."""
     # [START pubsub_test_topic_permissions]
     from google.cloud import pubsub_v1
 
-    # TODO(developer)
+    # TODO(developer): Choose an existing topic.
     # project_id = "your-project-id"
     # topic_id = "your-topic-id"
 
     client = pubsub_v1.PublisherClient()
-    topic_path = client.topic_path(project, topic_id)
+    topic_path = client.topic_path(project_id, topic_id)
 
     permissions_to_check = ["pubsub.topics.publish", "pubsub.topics.update"]
 
@@ -146,17 +146,17 @@ def check_topic_permissions(project, topic_id):
     # [END pubsub_test_topic_permissions]
 
 
-def check_subscription_permissions(project, subscription_id):
+def check_subscription_permissions(project_id, subscription_id):
     """Checks to which permissions are available on the given subscription."""
     # [START pubsub_test_subscription_permissions]
     from google.cloud import pubsub_v1
 
-    # TODO(developer)
+    # TODO(developer): Choose an existing subscription.
     # project_id = "your-project-id"
     # subscription_id = "your-subscription-id"
 
     client = pubsub_v1.SubscriberClient()
-    subscription_path = client.subscription_path(project, subscription_id)
+    subscription_path = client.subscription_path(project_id, subscription_id)
 
     permissions_to_check = [
         "pubsub.subscriptions.consume",
@@ -177,11 +177,38 @@ def check_subscription_permissions(project, subscription_id):
     # [END pubsub_test_subscription_permissions]
 
 
+def detach_subscription(project_id, subscription_id):
+    """Detaches a subscription from a topic and drop all messages retained in it."""
+    # [START pubsub_detach_subscription]
+    from google.api_core.exceptions import GoogleAPICallError, RetryError
+    from google.cloud import pubsub_v1
+
+    # TODO(developer): Choose an existing subscription.
+    # project_id = "your-project-id"
+    # subscription_id = "your-subscription-id"
+
+    publisher_client = pubsub_v1.PublisherClient()
+    subscriber_client = pubsub_v1.SubscriberClient()
+    subscription_path = subscriber_client.subscription_path(project_id, subscription_id)
+
+    try:
+        publisher_client.detach_subscription(subscription_path)
+    except (GoogleAPICallError, RetryError, ValueError, Exception) as err:
+        print(err)
+
+    subscription = subscriber_client.get_subscription(subscription_path)
+    if subscription.detached:
+        print("Subscription is detached.")
+    else:
+        print("Subscription is NOT detached.")
+    # [END pubsub_detach_subscription]
+
+
 if __name__ == "__main__":
     parser = argparse.ArgumentParser(
         description=__doc__, formatter_class=argparse.RawDescriptionHelpFormatter,
     )
-    parser.add_argument("project", help="Your Google Cloud project ID")
+    parser.add_argument("project_id", help="Your Google Cloud project ID")
 
     subparsers = parser.add_subparsers(dest="command")
 
@@ -215,17 +242,24 @@ def check_subscription_permissions(project, subscription_id):
     )
     check_subscription_permissions_parser.add_argument("subscription_id")
 
+    detach_subscription_parser = subparsers.add_parser(
+        "detach-subscription", help=detach_subscription.__doc__,
+    )
+    detach_subscription_parser.add_argument("subscription_id")
+
     args = parser.parse_args()
 
     if args.command == "get-topic-policy":
-        get_topic_policy(args.project, args.topic_id)
+        get_topic_policy(args.project_id, args.topic_id)
     elif args.command == "get-subscription-policy":
-        get_subscription_policy(args.project, args.subscription_id)
+        get_subscription_policy(args.project_id, args.subscription_id)
     elif args.command == "set-topic-policy":
-        set_topic_policy(args.project, args.topic_id)
+        set_topic_policy(args.project_id, args.topic_id)
     elif args.command == "set-subscription-policy":
-        set_subscription_policy(args.project, args.subscription_id)
+        set_subscription_policy(args.project_id, args.subscription_id)
     elif args.command == "check-topic-permissions":
-        check_topic_permissions(args.project, args.topic_id)
+        check_topic_permissions(args.project_id, args.topic_id)
     elif args.command == "check-subscription-permissions":
-        check_subscription_permissions(args.project, args.subscription_id)
+        check_subscription_permissions(args.project_id, args.subscription_id)
+    elif args.command == "detach-subscription":
+        detach_subscription(args.project_id, args.subscription_id)

samples/snippets/iam_test.py

@@ -21,9 +21,9 @@
 import iam
 
 UUID = uuid.uuid4().hex
-PROJECT = os.environ["GOOGLE_CLOUD_PROJECT"]
-TOPIC = "iam-test-topic-" + UUID
-SUBSCRIPTION = "iam-test-subscription-" + UUID
+PROJECT_ID = os.environ["GOOGLE_CLOUD_PROJECT"]
+TOPIC_ID = "iam-test-topic-" + UUID
+SUBSCRIPTION_ID = "iam-test-subscription-" + UUID
 
 
 @pytest.fixture(scope="module")
@@ -33,7 +33,7 @@ def publisher_client():
 
 @pytest.fixture(scope="module")
 def topic(publisher_client):
-    topic_path = publisher_client.topic_path(PROJECT, TOPIC)
+    topic_path = publisher_client.topic_path(PROJECT_ID, TOPIC_ID)
 
     try:
         publisher_client.delete_topic(topic_path)
@@ -56,7 +56,7 @@ def subscriber_client():
 
 @pytest.fixture
 def subscription(subscriber_client, topic):
-    subscription_path = subscriber_client.subscription_path(PROJECT, SUBSCRIPTION)
+    subscription_path = subscriber_client.subscription_path(PROJECT_ID, SUBSCRIPTION_ID)
 
     try:
         subscriber_client.delete_subscription(subscription_path)
@@ -71,37 +71,37 @@ def subscription(subscriber_client, topic):
 
 
 def test_get_topic_policy(topic, capsys):
-    iam.get_topic_policy(PROJECT, TOPIC)
+    iam.get_topic_policy(PROJECT_ID, TOPIC_ID)
 
     out, _ = capsys.readouterr()
     assert topic in out
 
 
 def test_get_subscription_policy(subscription, capsys):
-    iam.get_subscription_policy(PROJECT, SUBSCRIPTION)
+    iam.get_subscription_policy(PROJECT_ID, SUBSCRIPTION_ID)
 
     out, _ = capsys.readouterr()
     assert subscription in out
 
 
 def test_set_topic_policy(publisher_client, topic):
-    iam.set_topic_policy(PROJECT, TOPIC)
+    iam.set_topic_policy(PROJECT_ID, TOPIC_ID)
 
     policy = publisher_client.get_iam_policy(topic)
     assert "roles/pubsub.publisher" in str(policy)
     assert "allUsers" in str(policy)
 
 
 def test_set_subscription_policy(subscriber_client, subscription):
-    iam.set_subscription_policy(PROJECT, SUBSCRIPTION)
+    iam.set_subscription_policy(PROJECT_ID, SUBSCRIPTION_ID)
 
     policy = subscriber_client.get_iam_policy(subscription)
     assert "roles/pubsub.viewer" in str(policy)
     assert "allUsers" in str(policy)
 
 
 def test_check_topic_permissions(topic, capsys):
-    iam.check_topic_permissions(PROJECT, TOPIC)
+    iam.check_topic_permissions(PROJECT_ID, TOPIC_ID)
 
     out, _ = capsys.readouterr()
 
@@ -110,9 +110,17 @@ def test_check_topic_permissions(topic, capsys):
 
 
 def test_check_subscription_permissions(subscription, capsys):
-    iam.check_subscription_permissions(PROJECT, SUBSCRIPTION)
+    iam.check_subscription_permissions(PROJECT_ID, SUBSCRIPTION_ID)
 
     out, _ = capsys.readouterr()
 
     assert subscription in out
     assert "pubsub.subscriptions.consume" in out
+
+
+def test_detach_subscription(subscription, capsys):
+    iam.check_subscription_permissions(PROJECT_ID, SUBSCRIPTION_ID)
+
+    out, _ = capsys.readouterr()
+
+    assert "Subscription is detached" in out