Commit my random junk

[sandbox] / async / test1.py

diff --git a/async/test1.py b/async/test1.py
new file mode 100644 (file)
index 0000000..7b64042
--- /dev/null
+++ b/async/test1.py
@@ -0,0 +1,100 @@
+import asyncio
+import functools
+import logging
+import random
+import signal
+import string
+import uuid
+
+import attr
+
+logging.basicConfig(
+    level=logging.INFO,
+    format='%(asctime)s,%(msecs)d %(levelname)s: %(message)s',
+    datefmt='%H:%M:%S',
+)
+
+@attr.s
+class PubSubMessage:
+    instance_name = attr.ib()
+    message_id    = attr.ib(repr=False)
+    hostname      = attr.ib(repr=False, init=False)
+    restarted     = attr.ib(repr=False, default=False)
+    saved         = attr.ib(repr=False, default=False)
+    acked         = attr.ib(repr=False, default=False)
+    extended_cnt  = attr.ib(repr=False, default=0)
+
+    def __attrs_post_init__(self):
+        self.hostname = f"{self.instance_name}.example.net"
+
+async def publish(queue):
+    choices = string.ascii_lowercase + string.digits
+
+    while True:
+        msg_id = str(uuid.uuid4())
+        host_id = "".join(random.choices(choices, k=4))
+        instance_name = f"cattle-{host_id}"
+        msg = PubSubMessage(message_id=msg_id, instance_name=instance_name)
+        # publish an item
+        asyncio.create_task(queue.put(msg))
+        logging.debug(f"Published message {msg}")
+        # simulate randomness of publishing messages
+        await asyncio.sleep(random.random())
+
+async def restart_host(msg):
+    # unhelpful simulation of i/o work
+    await asyncio.sleep(random.random())
+    msg.restart = True
+    logging.info(f"Restarted {msg.hostname}")
+
+async def save(msg):
+    # unhelpful simulation of i/o work
+    await asyncio.sleep(random.random())
+    msg.save = True
+    logging.info(f"Saved {msg} into database")
+
+async def cleanup(msg, event):
+    # this will block the rest of the coro until `event.set` is called
+    await event.wait()
+    # unhelpful simulation of i/o work
+    await asyncio.sleep(random.random())
+    msg.acked = True
+    logging.info(f"Done. Acked {msg}")
+
+async def extend(msg, event):
+    while not event.is_set():
+        msg.extended_cnt += 1
+        logging.info(f"Extended deadline by 3 seconds for {msg}")
+        # want to sleep for less than the deadline amount
+        await asyncio.sleep(2)
+
+async def handle_message(msg):
+    event = asyncio.Event()
+    asyncio.create_task(extend(msg, event))
+    asyncio.create_task(cleanup(msg, event))
+
+    await asyncio.gather(save(msg), restart_host(msg))
+    event.set()
+
+async def consume(queue):
+    while True:
+        msg = await queue.get()
+        logging.info(f"Consumed {msg}")
+        asyncio.create_task(handle_message(msg))
+
+def main():
+    queue = asyncio.Queue()
+    loop = asyncio.get_event_loop()
+
+    try:
+        loop.create_task(publish(queue))
+        loop.create_task(consume(queue))
+        loop.run_forever()
+    except KeyboardInterrupt:
+        logging.info("Process interrupted")
+    finally:
+        loop.close()
+        logging.info("Successfully shutdown the Mayhem service.")
+
+if __name__ == "__main__":
+    main()