Files
DECNET/templates/postgres/server.py
anti 55896b0caa Add RFC 5424 syslog logging to all service templates
- decnet/logging/syslog_formatter.py: RFC 5424 formatter (local0 facility,
  decnet@55555 SD element ID, full escaping per §6.3.3)
- decnet/logging/file_handler.py: rotating file handler (10 MB / 5 backups),
  path configurable via DECNET_LOG_FILE env var
- templates/decnet_logging.py: combined syslog_line / write_syslog_file /
  forward_syslog helper distributed to all 22 service template dirs
- All templates/*/server.py: replaced ad-hoc JSON _forward/_log with RFC 5424
  syslog_line + write_syslog_file + forward_syslog
- All templates/*/Dockerfile: COPY decnet_logging.py /opt/
- DecnetConfig: added log_file field; CLI: --log-file flag;
  composer injects DECNET_LOG_FILE env var into service containers
- tests/test_syslog_formatter.py + tests/test_file_handler.py: 25 new tests

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-04-04 04:31:00 -03:00

118 lines
3.9 KiB
Python

#!/usr/bin/env python3
"""
PostgreSQLserver.
Reads the startup message, extracts username and database, responds with
an AuthenticationMD5Password challenge, logs the hash sent back, then
returns an error. Logs all interactions as JSON.
"""
import asyncio
import json
import os
import socket
import struct
from datetime import datetime, timezone
from decnet_logging import syslog_line, write_syslog_file, forward_syslog
NODE_NAME = os.environ.get("NODE_NAME", "pgserver")
SERVICE_NAME = "postgres"
LOG_TARGET = os.environ.get("LOG_TARGET", "")
SALT = b"\xde\xad\xbe\xef"
# AuthenticationMD5Password: 'R' + length(12) + auth_type(5) + salt(4)
_AUTH_MD5 = b"R" + struct.pack(">I", 12) + struct.pack(">I", 5) + SALT
def _error_response(message: str) -> bytes:
body = b"S" + b"FATAL\x00" + b"M" + message.encode() + b"\x00\x00"
return b"E" + struct.pack(">I", len(body) + 4) + body
def _log(event_type: str, severity: int = 6, **kwargs) -> None:
line = syslog_line(SERVICE_NAME, NODE_NAME, event_type, severity, **kwargs)
print(line, flush=True)
write_syslog_file(line)
forward_syslog(line, LOG_TARGET)
class PostgresProtocol(asyncio.Protocol):
def __init__(self):
self._transport = None
self._peer = None
self._buf = b""
self._state = "startup"
def connection_made(self, transport):
self._transport = transport
self._peer = transport.get_extra_info("peername", ("?", 0))
_log("connect", src=self._peer[0], src_port=self._peer[1])
def data_received(self, data):
self._buf += data
self._process()
def _process(self):
if self._state == "startup":
if len(self._buf) < 4:
return
msg_len = struct.unpack(">I", self._buf[:4])[0]
if len(self._buf) < msg_len:
return
msg = self._buf[:msg_len]
self._buf = self._buf[msg_len:]
self._handle_startup(msg)
elif self._state == "auth":
if len(self._buf) < 5:
return
msg_type = chr(self._buf[0])
msg_len = struct.unpack(">I", self._buf[1:5])[0]
if len(self._buf) < msg_len + 1:
return
payload = self._buf[5:msg_len + 1]
self._buf = self._buf[msg_len + 1:]
if msg_type == "p":
self._handle_password(payload)
def _handle_startup(self, msg: bytes):
# Startup message: length(4) + protocol_version(4) + params (key=value\0 pairs)
if len(msg) < 8:
return
proto = struct.unpack(">I", msg[4:8])[0]
if proto == 80877103: # SSL request
self._transport.write(b"N") # reject SSL
return
params_raw = msg[8:].split(b"\x00")
params = {}
for i in range(0, len(params_raw) - 1, 2):
k = params_raw[i].decode(errors="replace")
v = params_raw[i + 1].decode(errors="replace") if i + 1 < len(params_raw) else ""
if k:
params[k] = v
username = params.get("user", "")
database = params.get("database", "")
_log("startup", src=self._peer[0], username=username, database=database)
self._state = "auth"
self._transport.write(_AUTH_MD5)
def _handle_password(self, payload: bytes):
pw_hash = payload.rstrip(b"\x00").decode(errors="replace")
_log("auth", src=self._peer[0], pw_hash=pw_hash)
self._transport.write(_error_response("password authentication failed"))
self._transport.close()
def connection_lost(self, exc):
_log("disconnect", src=self._peer[0] if self._peer else "?")
async def main():
_log("startup", msg=f"PostgreSQL server starting as {NODE_NAME}")
loop = asyncio.get_running_loop()
server = await loop.create_server(PostgresProtocol, "0.0.0.0", 5432)
async with server:
await server.serve_forever()
if __name__ == "__main__":
asyncio.run(main())