setting up bluesky firehose

python/data_science/firehose_producer.py

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+"""Bluesky Jetstream firehose to Kafka producer.
+
+Connects to the Bluesky Jetstream WebSocket API with zstd compression,
+filters for post creation events, and produces them to a Kafka topic.
+
+Usage:
+    firehose-producer
+    firehose-producer --kafka-servers kafka:9092 --topic bluesky.firehose.posts
+"""
+
+from __future__ import annotations
+
+import json
+import logging
+import signal
+from os import getenv
+from threading import Event
+from typing import Annotated
+
+import typer
+from compression import zstd
+from confluent_kafka import KafkaError, KafkaException, Producer
+from websockets.exceptions import ConnectionClosed
+from websockets.sync.client import connect
+
+logger = logging.getLogger(__name__)
+
+JETSTREAM_URL = "wss://jetstream2.us-east.bsky.network/subscribe"
+DEFAULT_TOPIC = "bluesky.firehose.posts"
+DEFAULT_KAFKA_SERVERS = "localhost:9092"
+POLL_INTERVAL = 100
+POST_COLLECTION = "app.bsky.feed.post"
+
+shutdown_event = Event()
+
+app = typer.Typer(help="Stream Bluesky firehose posts into Kafka.")
+
+
+@app.command()
+def main(
+    kafka_servers: Annotated[str, typer.Option(help="Kafka bootstrap servers")] = "",
+    topic: Annotated[str, typer.Option(help="Kafka topic to produce to")] = "",
+    collections: Annotated[str, typer.Option(help="Comma-separated collections to subscribe to")] = POST_COLLECTION,
+) -> None:
+    """Connect to Bluesky Jetstream and produce post events to Kafka."""
+    logging.basicConfig(
+        level=logging.INFO,
+        format="%(asctime)s %(levelname)s %(message)s",
+        datefmt="%H:%M:%S",
+    )
+
+    servers = kafka_servers or getenv("KAFKA_BOOTSTRAP_SERVERS", DEFAULT_KAFKA_SERVERS)
+    topic_name = topic or getenv("BLUESKY_FIREHOSE_TOPIC", DEFAULT_TOPIC)
+
+    signal.signal(signal.SIGTERM, _handle_shutdown)
+    signal.signal(signal.SIGINT, _handle_shutdown)
+
+    producer = _create_producer(servers)
+    cursor: int | None = None
+
+    logger.info("Starting firehose producer → %s on %s", topic_name, servers)
+
+    while not shutdown_event.is_set():
+        try:
+            cursor = _stream_loop(producer, topic_name, collections, cursor)
+        except (ConnectionClosed, OSError):
+            logger.exception("WebSocket disconnected, reconnecting")
+        except KafkaException:
+            logger.exception("Kafka error, reconnecting")
+
+        if not shutdown_event.is_set():
+            logger.info("Reconnecting in 5 seconds (cursor=%s)", cursor)
+            shutdown_event.wait(timeout=5)
+
+    logger.info("Shutting down, flushing producer")
+    producer.flush(timeout=30)
+    logger.info("Producer shutdown complete")
+
+
+def _stream_loop(
+    producer: Producer,
+    topic: str,
+    collections: str,
+    cursor: int | None,
+) -> int | None:
+    """Connect to Jetstream and stream messages to Kafka until disconnected.
+
+    Args:
+        producer: The Kafka producer instance.
+        topic: Kafka topic name.
+        collections: Comma-separated AT Protocol collections to subscribe to.
+        cursor: Optional microsecond timestamp to resume from.
+
+    Returns:
+        The last processed time_us cursor value.
+    """
+    url = _build_jetstream_url(collections, cursor)
+    logger.info("Connecting to %s", url)
+
+    message_count = 0
+    last_cursor = cursor
+
+    with connect(url, additional_headers={"Accept-Encoding": "zstd"}) as websocket:
+        logger.info("Connected to Jetstream")
+
+        while not shutdown_event.is_set():
+            try:
+                raw_frame = websocket.recv(timeout=10)
+            except TimeoutError:
+                producer.poll(0)
+                continue
+
+            text = _decode_frame(raw_frame)
+            message = json.loads(text)
+
+            time_us = message.get("time_us")
+            if time_us is not None:
+                last_cursor = time_us
+
+            if not _is_post_create(message):
+                continue
+
+            did = message.get("did", "")
+
+            try:
+                producer.produce(
+                    topic,
+                    key=did.encode(),
+                    value=text.encode() if isinstance(text, str) else text,
+                    callback=_delivery_callback,
+                )
+            except BufferError:
+                logger.warning("Producer buffer full, flushing")
+                producer.flush(timeout=10)
+                producer.produce(
+                    topic,
+                    key=did.encode(),
+                    value=text.encode() if isinstance(text, str) else text,
+                    callback=_delivery_callback,
+                )
+
+            message_count += 1
+            if message_count % POLL_INTERVAL == 0:
+                producer.poll(0)
+
+            if message_count % 10000 == 0:
+                logger.info("Produced %d messages (cursor=%s)", message_count, last_cursor)
+
+    return last_cursor
+
+
+def _build_jetstream_url(collections: str, cursor: int | None) -> str:
+    """Build the Jetstream WebSocket URL with query parameters.
+
+    Args:
+        collections: Comma-separated collection names.
+        cursor: Optional microsecond timestamp for resumption.
+
+    Returns:
+        The full WebSocket URL.
+    """
+    params = ["compress=true"]
+    for raw_collection in collections.split(","):
+        cleaned = raw_collection.strip()
+        if cleaned:
+            params.append(f"wantedCollections={cleaned}")
+    if cursor is not None:
+        params.append(f"cursor={cursor}")
+    return f"{JETSTREAM_URL}?{'&'.join(params)}"
+
+
+def _decode_frame(frame: str | bytes) -> str:
+    """Decode a WebSocket frame, decompressing zstd if binary.
+
+    Jetstream with compress=true sends zstd-compressed binary frames.
+
+    Args:
+        frame: Raw WebSocket frame data.
+
+    Returns:
+        The decoded JSON string.
+    """
+    if isinstance(frame, bytes):
+        return zstd.decompress(frame).decode()
+    return frame
+
+
+def _is_post_create(message: dict) -> bool:
+    """Check if a Jetstream message is a post creation commit."""
+    if message.get("kind") != "commit":
+        return False
+    commit = message.get("commit", {})
+    return commit.get("operation") == "create" and commit.get("collection") == POST_COLLECTION
+
+
+def _create_producer(servers: str) -> Producer:
+    """Create a configured Kafka producer.
+
+    Args:
+        servers: Kafka bootstrap servers string.
+
+    Returns:
+        A configured confluent_kafka.Producer.
+    """
+    config = {
+        "bootstrap.servers": servers,
+        "linger.ms": 50,
+        "batch.size": 65536,
+        "compression.type": "zstd",
+        "acks": "all",
+        "retries": 5,
+        "retry.backoff.ms": 500,
+    }
+    return Producer(config)
+
+
+def _delivery_callback(error: KafkaError | None, _message: object) -> None:
+    """Log delivery failures from the Kafka producer."""
+    if error is not None:
+        logger.error("Kafka delivery failed: %s", error)
+
+
+def _handle_shutdown(_signum: int, _frame: object) -> None:
+    """Signal handler to trigger graceful shutdown."""
+    logger.info("Shutdown signal received")
+    shutdown_event.set()
+
+
+if __name__ == "__main__":
+    app()