Rewrote Crabstero from Java to Python.

- Replaced Javacord with discord.py.
- Replaced Redis backend with SQLite via aiosqlite.
- Replaced Gradle build with pyproject.toml and uv.
- Added setuptools-scm for automatic versioning from git tags.
- Added argparse CLI with systemd credential support for the bot token.
- Replaced per-channel ingestion tasks with a bounded queue and worker pool.
- Removed Dockerfile and Gitea Actions workflow.

crabstero/__main__.py

@@ -0,0 +1,130 @@
+# Copyright 2026 Logan Fick
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""
+Entry point for the Crabstero Discord bot.
+
+Provides an argparse CLI with environment variable and systemd credential fallbacks for --token and --database-path.
+"""
+
+import argparse
+import asyncio
+import logging
+import os
+import signal
+import sys
+
+from crabstero._version import version as crabstero_version
+from crabstero.bot import Crabstero
+
+logger = logging.getLogger("crabstero")
+
+
+def _read_credential(name: str) -> str | None:
+    """
+    Read a value from a systemd credential file.
+
+    Looks for a file named *name* inside the directory pointed to by the
+    ``CREDENTIALS_DIRECTORY`` environment variable (set automatically by
+    systemd when ``LoadCredential=`` or ``SetCredential=`` is used).
+
+    :param name: Credential name to look up.
+    :return: The credential value, or ``None`` if unavailable.
+    """
+    credentials_dir = os.environ.get("CREDENTIALS_DIRECTORY")
+    if credentials_dir is None:
+        return None
+
+    try:
+        return (
+            open(os.path.join(credentials_dir, name)).read().strip()  # noqa: SIM115
+        )
+    except OSError:
+        return None
+
+
+def _parse_args(argv: list[str] | None = None) -> argparse.Namespace:
+    """
+    Parses command-line arguments with environment variable fallbacks.
+
+    :param argv: Optional argument list (defaults to sys.argv[1:]).
+    :return: Parsed arguments namespace.
+    """
+    parser = argparse.ArgumentParser(
+        prog="crabstero",
+        description="Crabstero - the simple nonversation Discord bot.",
+    )
+    parser.add_argument(
+        "--token",
+        default=os.environ.get("TOKEN") or _read_credential("token"),
+        help="Discord bot token (default: TOKEN environment variable or systemd credential 'token').",
+    )
+    parser.add_argument(
+        "--database-path",
+        "--database",
+        default=os.environ.get("DATABASE_PATH", "crabstero.db"),
+        help='Path to the SQLite database file (default: DATABASE_PATH environment variable or "crabstero.db").',
+    )
+    parser.add_argument(
+        "--ingestion-workers",
+        type=int,
+        default=int(os.environ.get("INGESTION_WORKERS", "4")),
+        help="Number of concurrent ingestion workers (default: INGESTION_WORKERS environment variable or 4).",
+    )
+
+    args = parser.parse_args(argv)
+
+    if args.token is None:
+        parser.error(
+            "a Discord bot token is required via --token, the TOKEN environment variable, or a systemd credential named 'token'"
+        )
+
+    return args
+
+
+def main() -> None:
+    """
+    Main entry point. Parses arguments, configures logging, and starts the bot.
+    """
+    args = _parse_args()
+
+    logging.basicConfig(
+        level=logging.INFO,
+        format="[%(asctime)s] [%(name)s] [%(levelname)s] %(message)s",
+    )
+
+    logger.info("Starting Crabstero %s...", crabstero_version)
+
+    bot = Crabstero(
+        token=args.token,
+        database_path=args.database_path,
+        ingestion_workers=args.ingestion_workers,
+    )
+
+    async def _run() -> None:
+        async with bot:
+            await bot.start()
+
+    # Make SIGTERM behave like SIGINT so systemd stop triggers the same
+    # clean shutdown path (context manager __aexit__ -> bot.close()).
+    signal.signal(signal.SIGTERM, signal.default_int_handler)
+
+    try:
+        asyncio.run(_run())
+    except KeyboardInterrupt:
+        logger.info("Interrupted.")
+
+
+if __name__ == "__main__":
+    main()