move channel into try block

pp/pp/config.py

@@ -3,7 +3,7 @@
 rabbitmq_host = os.getenv("RABBITMQ_HOST", "localhost")
 prediction_queue = os.getenv("PREDICTION_QUEUE", "prediction")
 
-sleep_interval = float(os.getenv("SLEEP_INTERVAL", "0.5"))
+task_sleep_interval = float(os.getenv("SLEEP_INTERVAL", "0.5"))
 
 api_protocol = os.getenv("API_PROTOCOL", "http")
 api_port = int(os.getenv("API_PORT", "8000"))

pp/pp/main.py

@@ -5,9 +5,9 @@
 import pika
 from pika.exceptions import AMQPConnectionError
 
-from .prediction import predict_on_cell
+from .prediction import predict_on_cell_coords
 from .cells import get_res_zero_cell_coords
-from .config import rabbitmq_host, prediction_queue, sleep_interval
+from .config import rabbitmq_host, prediction_queue, task_sleep_interval
 
 logging.basicConfig(level=logging.INFO, format="%(asctime)s [%(levelname)s] %(message)s")
 log = logging.getLogger(__name__)
@@ -17,35 +17,34 @@ async def main():
     """initializes process of getting sky brightness predictions for h3 cells;
     publishing them to prediction queue as available.
 
-    n.b. with 122 res 0 cells on current machine, this setup will publish at a rate of 1.4m/s
+    n.b. with 122 res 0 cells on 2016 macbook, this will publish at a rate of 1.4m/s
     """
 
     try:
         connection = pika.BlockingConnection(pika.ConnectionParameters(rabbitmq_host))
+        channel = connection.channel()
+        channel.queue_declare(queue=prediction_queue)
     except AMQPConnectionError as e:
         import sys
-        log.error("could not form amqp connection!")
+
+        log.error(f"could not form amqp connection {e}")
         log.warning("exiting")
         sys.exit(1)
     except Exception as e:
-        log.error(f"could not start process because {e}")
+        log.error(f"could not start publisher because {e}")
     else:
-        channel = connection.channel()
-        channel.queue_declare(queue=prediction_queue)
-
-        all_h3_cell_coords = get_res_zero_cell_coords()
-
-        log.info(f"using {len(all_h3_cell_coords)} resolution zero cells")
-
-        async with httpx.AsyncClient() as client:
-            while True:
-                try:
-                    for cell_coordinates in all_h3_cell_coords:
-                        await asyncio.create_task(predict_on_cell(client, cell_coordinates, channel))
-                        await asyncio.sleep(sleep_interval)
-                except Exception as e:
-                    log.error(f"could not continue publishing because {e}")
-                    channel.close()
+        resolution_zero_cell_coords = get_res_zero_cell_coords()
+        log.debug(f"using {len(resolution_zero_cell_coords)} resolution zero cells")
+
+        try:
+            async with httpx.AsyncClient() as client:
+                while True:
+                    for cell_coords in resolution_zero_cell_coords:
+                        await asyncio.create_task(predict_on_cell_coords(client, cell_coords, channel))
+                        await asyncio.sleep(task_sleep_interval)
+        except Exception as e:
+            log.error(f"could not continue publishing because {e}")
+            channel.close()
 
 
 if __name__ == "__main__":

pp/pp/message.py

@@ -8,4 +8,5 @@ class PredictionMessage:
     lon: float
     # magnitudes per square arc second
     mpsas: float
+    # id of the h3 cell
     h3_id: str

pp/pp/prediction.py

@@ -18,7 +18,6 @@
 async def get_prediction_message_for_lat_lon(client: httpx.AsyncClient, lat: float, lon: float) -> PredictionMessage:
     res = await client.get(prediction_endpoint_url, params={"lat": lat, "lon": lon})
     res.raise_for_status()
-
     data = res.json()
     if (mpsas := data.get("sky_brightness", None)) is None:
         raise ValueError("no sky brightness reading in api response")
@@ -32,7 +31,7 @@ async def get_prediction_message_for_lat_lon(client: httpx.AsyncClient, lat: flo
     )
 
 
-async def predict_on_cell(client: httpx.AsyncClient, coords: Tuple[float, float], channel: Channel):
+async def predict_on_cell_coords(client: httpx.AsyncClient, coords: Tuple[float, float], channel: Channel):
     """retrieve and publish a sky brightness prediction at coords for the h3 cell"""
     import json