core: add network client module and main node (leanEthereum#275)

* core: add network client module and main node

* cleanup

Author: tcoratger

src/lean_spec/__main__.py

@@ -0,0 +1,164 @@
+"""
+Lean consensus node CLI entry point.
+
+Run a minimal lean consensus client that can sync with other lean consensus nodes.
+
+Usage::
+
+    python -m lean_spec --genesis genesis.json --bootnode /ip4/127.0.0.1/tcp/9000
+
+Options:
+    --genesis       Path to genesis JSON file (required)
+    --bootnode      Multiaddr of bootnode to connect to (can be repeated)
+    --listen        Address to listen on (default: /ip4/0.0.0.0/tcp/9000)
+"""
+
+from __future__ import annotations
+
+import argparse
+import asyncio
+import logging
+from pathlib import Path
+
+from lean_spec.subspecs.containers import Checkpoint
+from lean_spec.subspecs.containers.slot import Slot
+from lean_spec.subspecs.genesis import GenesisConfig
+from lean_spec.subspecs.networking.client import LiveNetworkEventSource
+from lean_spec.subspecs.networking.reqresp.message import Status
+from lean_spec.subspecs.node import Node, NodeConfig
+from lean_spec.types import Bytes32
+
+logger = logging.getLogger(__name__)
+
+
+def setup_logging(verbose: bool = False) -> None:
+    """Configure logging for the node."""
+    level = logging.DEBUG if verbose else logging.INFO
+    logging.basicConfig(
+        level=level,
+        format="%(asctime)s %(levelname)s %(name)s: %(message)s",
+        datefmt="%Y-%m-%d %H:%M:%S",
+    )
+
+
+async def run_node(
+    genesis_path: Path,
+    bootnodes: list[str],
+    listen_addr: str,
+) -> None:
+    """
+    Run the lean consensus node.
+
+    Args:
+        genesis_path: Path to genesis JSON file.
+        bootnodes: List of bootnode multiaddrs to connect to.
+        listen_addr: Address to listen on.
+    """
+    # Load genesis configuration.
+    logger.info("Loading genesis from %s", genesis_path)
+    genesis = GenesisConfig.from_json_file(genesis_path)
+    logger.info(
+        "Genesis loaded: time=%d, validators=%d",
+        genesis.genesis_time,
+        len(genesis.genesis_validators),
+    )
+
+    # Create network transport.
+    event_source = LiveNetworkEventSource.create()
+
+    # Create initial status for handshakes.
+    #
+    # At genesis, our finalized and head are both the genesis block.
+    genesis_status = Status(
+        finalized=Checkpoint(root=Bytes32.zero(), slot=Slot(0)),
+        head=Checkpoint(root=Bytes32.zero(), slot=Slot(0)),
+    )
+    event_source.set_status(genesis_status)
+
+    # Create node configuration.
+    config = NodeConfig(
+        genesis_time=genesis.genesis_time,
+        validators=genesis.to_validators(),
+        event_source=event_source,
+        network=event_source.reqresp_client,
+    )
+
+    # Create the node.
+    node = Node.from_genesis(config)
+    logger.info("Node initialized, peer_id=%s", event_source.connection_manager.peer_id)
+
+    # Update status with actual genesis block root.
+    #
+    # At genesis, the head and finalized are both the genesis block.
+    # The store.head is initialized to the genesis block root.
+    genesis_root = node.store.head
+    updated_status = Status(
+        finalized=Checkpoint(root=genesis_root, slot=Slot(0)),
+        head=Checkpoint(root=genesis_root, slot=Slot(0)),
+    )
+    event_source.set_status(updated_status)
+
+    # Connect to bootnodes.
+    for bootnode in bootnodes:
+        logger.info("Connecting to bootnode %s", bootnode)
+        peer_id = await event_source.dial(bootnode)
+        if peer_id:
+            logger.info("Connected to bootnode, peer_id=%s", peer_id)
+        else:
+            logger.warning("Failed to connect to bootnode %s", bootnode)
+
+    # Start listening (in background).
+    if listen_addr:
+        logger.info("Starting listener on %s", listen_addr)
+        asyncio.create_task(event_source.listen(listen_addr))
+
+    # Run the node.
+    logger.info("Starting consensus node...")
+    event_source._running = True
+    await node.run()
+
+
+def main() -> None:
+    """CLI entry point."""
+    parser = argparse.ArgumentParser(
+        description="Lean consensus node",
+        formatter_class=argparse.RawDescriptionHelpFormatter,
+        epilog=__doc__,
+    )
+    parser.add_argument(
+        "--genesis",
+        required=True,
+        type=Path,
+        help="Path to genesis JSON file",
+    )
+    parser.add_argument(
+        "--bootnode",
+        action="append",
+        default=[],
+        dest="bootnodes",
+        help="Bootnode multiaddr (can be repeated)",
+    )
+    parser.add_argument(
+        "--listen",
+        default="/ip4/0.0.0.0/tcp/9000",
+        help="Address to listen on (default: /ip4/0.0.0.0/tcp/9000)",
+    )
+    parser.add_argument(
+        "-v",
+        "--verbose",
+        action="store_true",
+        help="Enable debug logging",
+    )
+
+    args = parser.parse_args()
+
+    setup_logging(args.verbose)
+
+    try:
+        asyncio.run(run_node(args.genesis, args.bootnodes, args.listen))
+    except KeyboardInterrupt:
+        logger.info("Shutting down...")
+
+
+if __name__ == "__main__":
+    main()

src/lean_spec/subspecs/networking/client/__init__.py

@@ -0,0 +1,24 @@
+"""
+Network Client Module.
+
+Bridges the transport layer to the sync service by implementing
+the NetworkRequester and NetworkEventSource protocols.
+
+Components
+----------
+ReqRespClient
+    Implements NetworkRequester using ConnectionManager.
+    Handles BlocksByRoot and Status requests.
+
+LiveNetworkEventSource
+    Implements NetworkEventSource.
+    Bridges connection events to NetworkService events.
+"""
+
+from .event_source import LiveNetworkEventSource
+from .reqresp_client import ReqRespClient
+
+__all__ = [
+    "LiveNetworkEventSource",
+    "ReqRespClient",
+]