Configure black formatter

.flake8

@@ -0,0 +1,3 @@
+[flake8]
+max-line-length = 88
+extend-ignore = E203, E704

.github/workflows/build.yml

@@ -38,6 +38,8 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@v4
 
+      - uses: psf/black@stable
+
       - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@v5
         with:

.vscode/settings.json

@@ -0,0 +1,3 @@
+{
+  "editor.defaultFormatter": "ms-python.black-formatter"
+}

gcn_email/cli.py

@@ -20,22 +20,31 @@ def host_port(host_port_str):
     # Parse netloc like it is done for HTTP URLs.
     # This ensures that we will get the correct behavior for hostname:port
     # splitting even for IPv6 addresses.
-    return urllib.parse.urlparse(f'http://{host_port_str}')
+    return urllib.parse.urlparse(f"http://{host_port_str}")
 
 
 @click.command()
 @click.option(
-    '--prometheus', type=host_port, default=':8000', show_default=True,
-    help='Hostname and port to listen on for Prometheus metric reporting')
+    "--prometheus",
+    type=host_port,
+    default=":8000",
+    show_default=True,
+    help="Hostname and port to listen on for Prometheus metric reporting",
+)
 @click.option(
-    '--loglevel', type=click.Choice(logging._levelToName.values()),
-    default='INFO', show_default=True, help='Log level')
+    "--loglevel",
+    type=click.Choice(logging._levelToName.values()),
+    default="INFO",
+    show_default=True,
+    help="Log level",
+)
 def main(prometheus, loglevel):
     logging.basicConfig(level=loglevel)
 
-    prometheus_client.start_http_server(prometheus.port,
-                                        prometheus.hostname or '0.0.0.0')
-    log.info('Prometheus listening on %s', prometheus.netloc)
+    prometheus_client.start_http_server(
+        prometheus.port, prometheus.hostname or "0.0.0.0"
+    )
+    log.info("Prometheus listening on %s", prometheus.netloc)
 
     consumer = connect_as_consumer()
     subscribe_to_topics(consumer)

gcn_email/core.py

@@ -18,21 +18,22 @@
 from .helpers import periodic_task
 from . import metrics
 
-SESV2 = boto3.client('sesv2')
+SESV2 = boto3.client("sesv2")
 SENDER = f'GCN Notices <{os.environ["EMAIL_SENDER"]}>'
 
 # Maximum send rate
-MAX_SENDS = boto3.client('ses').get_send_quota()['MaxSendRate']
+MAX_SENDS = boto3.client("ses").get_send_quota()["MaxSendRate"]
 
 log = logging.getLogger(__name__)
 
 
 def get_email_notification_subscription_table():
-    client = boto3.client('ssm')
+    client = boto3.client("ssm")
     result = client.get_parameter(
-        Name='/RemixGcnProduction/tables/email_notification_subscription')
-    table_name = result['Parameter']['Value']
-    return boto3.resource('dynamodb').Table(table_name)
+        Name="/RemixGcnProduction/tables/email_notification_subscription"
+    )
+    table_name = result["Parameter"]["Value"]
+    return boto3.resource("dynamodb").Table(table_name)
 
 
 def query_and_project_subscribers(table, topic):
@@ -43,20 +44,21 @@ def query_and_project_subscribers(table, topic):
     """
     try:
         response = table.query(
-            IndexName='byTopic',
+            IndexName="byTopic",
             ProjectionExpression="#topic, recipient",
             ExpressionAttributeNames={"#topic": "topic"},
-            KeyConditionExpression=(Key('topic').eq(topic)))
+            KeyConditionExpression=(Key("topic").eq(topic)),
+        )
     except Exception:
-        log.exception('Failed to query recipients')
+        log.exception("Failed to query recipients")
         return []
     else:
-        return [x['recipient'] for x in response['Items']]
+        return [x["recipient"] for x in response["Items"]]
 
 
 def connect_as_consumer():
-    log.info('Connecting to Kafka')
-    return Consumer(config_from_env(), **{'enable.auto.commit': False})
+    log.info("Connecting to Kafka")
+    return Consumer(config_from_env(), **{"enable.auto.commit": False})
 
 
 @periodic_task(86400)
@@ -65,26 +67,32 @@ def subscribe_to_topics(consumer: Consumer):
     # This may need to be updated if new topics have a format different than
     # 'gcn.classic.[text | voevent | binary].[topic]'
     topics = [
-        topic for topic in consumer.list_topics().topics
-        if topic.startswith('gcn.')]
-    log.info('Subscribing to topics: %r', topics)
+        topic for topic in consumer.list_topics().topics if topic.startswith("gcn.")
+    ]
+    log.info("Subscribing to topics: %r", topics)
     consumer.subscribe(topics)
 
 
 def kafka_message_to_email(message):
     topic = message.topic()
     email_message = EmailMessage()
-    if topic.startswith('gcn.classic.text.'):
+    if topic.startswith("gcn.classic.text."):
         email_message.set_content(message.value().decode())
-    elif topic.startswith('gcn.classic.voevent.'):
+    elif topic.startswith("gcn.classic.voevent."):
         email_message.add_attachment(
-            message.value(), filename='notice.xml',
-            maintype='application', subtype='xml')
+            message.value(),
+            filename="notice.xml",
+            maintype="application",
+            subtype="xml",
+        )
     else:
         email_message.add_attachment(
-            message.value(), filename='notice.bin',
-            maintype='application', subtype='octet-stream')
-    email_message['Subject'] = topic
+            message.value(),
+            filename="notice.bin",
+            maintype="application",
+            subtype="octet-stream",
+        )
+    email_message["Subject"] = topic
     return email_message.as_bytes()
 
 
@@ -94,19 +102,19 @@ def recieve_alerts(consumer):
         for message in consumer.consume(timeout=1):
             error = message.error()
             if error is not None:
-                log.error('Error consuming message: %s', error)
+                log.error("Error consuming message: %s", error)
                 continue
             topic = message.topic()
             metrics.received.labels(topic).inc()
             recipients = query_and_project_subscribers(table, topic)
             if recipients:
-                log.info('Sending message for topic %s', topic)
+                log.info("Sending message for topic %s", topic)
                 email = kafka_message_to_email(message)
                 for recipient in recipients:
                     try:
                         send_raw_ses_message_to_recipient(email, recipient)
                     except Exception:
-                        log.exception('Failed to send message')
+                        log.exception("Failed to send message")
                     else:
                         metrics.sent.labels(topic, recipient).inc()
             consumer.commit(message)
@@ -123,12 +131,13 @@ def recieve_alerts(consumer):
         SESV2.exceptions.SendingPausedException,
         SESV2.exceptions.TooManyRequestsException,
     ),
-    max_time=300
+    max_time=300,
 )
 @limits(calls=MAX_SENDS, period=1)
 @metrics.send_request_latency_seconds.time()
 def send_raw_ses_message_to_recipient(bytes, recipient):
     SESV2.send_email(
         FromEmailAddress=SENDER,
-        Destination={'ToAddresses': [recipient]},
-        Content={'Raw': {'Data': bytes}})
+        Destination={"ToAddresses": [recipient]},
+        Content={"Raw": {"Data": bytes}},
+    )

gcn_email/helpers.py

@@ -15,11 +15,13 @@ def inner_wrap():
                     try:
                         function(*args, **kwargs)
                     except Exception:
-                        log.exception('Periodic task failed')
+                        log.exception("Periodic task failed")
                     stop.wait(interval)
 
             t = threading.Thread(target=inner_wrap, daemon=True)
             t.start()
             return stop
+
         return wrap
+
     return outer_wrap

gcn_email/metrics.py

@@ -9,20 +9,17 @@
 import prometheus_client
 
 received = prometheus_client.Counter(
-    'received',
-    'Kafka messages received',
-    labelnames=['topic'],
-    namespace=__package__)
+    "received", "Kafka messages received", labelnames=["topic"], namespace=__package__
+)
 
 
 sent = prometheus_client.Counter(
-    'sent',
-    'Emails sent',
-    labelnames=['topic', 'address'],
-    namespace=__package__)
+    "sent", "Emails sent", labelnames=["topic", "address"], namespace=__package__
+)
 
 
 send_request_latency_seconds = prometheus_client.Histogram(
-    'send_request_latency_seconds',
-    'Time taken to send each message',
-    namespace=__package__)
+    "send_request_latency_seconds",
+    "Time taken to send each message",
+    namespace=__package__,
+)

pyproject.toml

@@ -15,6 +15,7 @@ click = "^8.1.3"
 prometheus-client = "^0.17.0"
 
 [tool.poetry.group.dev.dependencies]
+black = "*"
 flake8 = "*"
 
 [tool.poetry.scripts]