71 lines
2.6 KiB
Python
71 lines
2.6 KiB
Python
from __future__ import annotations
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import gzip
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import socket
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from datetime import datetime, timezone
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from pathlib import Path
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def rotate_log_file(output_path: Path, *, max_archives: int) -> Path | None:
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"""Archive the active syslog file as gzip and retain only recent archives."""
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if not output_path.exists() or output_path.stat().st_size == 0:
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return None
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timestamp = datetime.now(timezone.utc).strftime("%Y%m%dT%H%M%SZ")
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archive = output_path.with_name(f"{output_path.name}.{timestamp}.gz")
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suffix = 1
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while archive.exists():
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archive = output_path.with_name(f"{output_path.name}.{timestamp}.{suffix}.gz")
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suffix += 1
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with output_path.open("rb") as source, gzip.open(archive, "wb") as destination:
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while chunk := source.read(1024 * 1024):
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destination.write(chunk)
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output_path.unlink()
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archives = sorted(output_path.parent.glob(f"{output_path.name}.*.gz"), key=lambda path: path.stat().st_mtime, reverse=True)
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for stale_archive in archives[max(0, max_archives):]:
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stale_archive.unlink()
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return archive
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def listen_udp_syslog(
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host: str,
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port: int,
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output: str,
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*,
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max_bytes: int = 65535,
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rotate_bytes: int = 25 * 1024 * 1024,
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rotate_count: int = 14,
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quiet: bool = False,
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) -> None:
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output_path = Path(output)
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output_path.parent.mkdir(parents=True, exist_ok=True)
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if rotate_bytes < 0 or rotate_count < 0:
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raise ValueError("rotation settings must be zero or positive")
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sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
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sock.bind((host, port))
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print(f"Listening for UDP syslog on {host}:{port}")
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print(f"Writing logs to {output_path}")
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if rotate_bytes:
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print(f"Rotation: {rotate_bytes} bytes, retaining {rotate_count} gzip archives")
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with output_path.open("a", encoding="utf-8", buffering=1) as handle:
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while True:
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data, address = sock.recvfrom(max_bytes)
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message = data.decode("utf-8", errors="replace").strip()
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if not message:
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continue
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line = f"{message}\n"
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line_bytes = len(line.encode("utf-8"))
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if rotate_bytes and output_path.stat().st_size + line_bytes > rotate_bytes:
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handle.close()
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archive = rotate_log_file(output_path, max_archives=rotate_count)
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if archive and not quiet:
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print(f"Rotated syslog to {archive}")
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handle = output_path.open("a", encoding="utf-8", buffering=1)
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handle.write(line)
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if not quiet:
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print(f"{address[0]}:{address[1]} {message}")
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