Break out block listener to a start / stop daemon instead of running on startup

listener.py

@@ -0,0 +1,68 @@
+import logging
+import os
+import time
+
+from web3 import Web3
+
+from mev_inspect.block import get_latest_block_number
+from mev_inspect.crud.latest_block_update import (
+    find_latest_block_update,
+    update_latest_block,
+)
+from mev_inspect.db import get_session
+from mev_inspect.inspect_block import inspect_block
+from mev_inspect.provider import get_base_provider
+from mev_inspect.signal_handler import GracefulKiller
+
+
+logging.basicConfig(filename="listener.log", level=logging.INFO)
+logger = logging.getLogger(__name__)
+
+
+def run():
+    rpc = os.getenv("RPC_URL")
+    if rpc is None:
+        raise RuntimeError("Missing environment variable RPC_URL")
+
+    logger.info("Starting...")
+
+    killer = GracefulKiller()
+
+    db_session = get_session()
+    base_provider = get_base_provider(rpc)
+    w3 = Web3(base_provider)
+
+    latest_block_number = get_latest_block_number(w3)
+
+    while not killer.kill_now:
+        last_written_block = find_latest_block_update(db_session)
+        logger.info(f"Latest block: {latest_block_number}")
+        logger.info(f"Last written block: {last_written_block}")
+
+        if last_written_block is None or last_written_block < latest_block_number:
+            block_number = (
+                latest_block_number
+                if last_written_block is None
+                else last_written_block + 1
+            )
+
+            logger.info(f"Writing block: {block_number}")
+
+            inspect_block(
+                db_session,
+                base_provider,
+                w3,
+                block_number,
+                should_write_classified_traces=False,
+                should_cache=False,
+            )
+            update_latest_block(db_session, block_number)
+        else:
+            time.sleep(5)
+            latest_block_number = get_latest_block_number(w3)
+
+    logger.info("Stopping...")
+
+
+if __name__ == "__main__":
+    run()