Rename project to ddns-service

src/ddns_service/logging.py

@@ -0,0 +1,141 @@
+"""Centralized logging configuration."""
+
+import logging
+import logging.handlers
+import secrets
+from contextvars import ContextVar
+
+# Transaction ID context (thread-safe per-request)
+_txn_id = ContextVar("txn_id", default="-")
+
+# Syslog facility mapping
+SYSLOG_FACILITIES = {
+    "daemon": logging.handlers.SysLogHandler.LOG_DAEMON,
+    "user": logging.handlers.SysLogHandler.LOG_USER,
+    "local0": logging.handlers.SysLogHandler.LOG_LOCAL0,
+    "local1": logging.handlers.SysLogHandler.LOG_LOCAL1,
+    "local2": logging.handlers.SysLogHandler.LOG_LOCAL2,
+    "local3": logging.handlers.SysLogHandler.LOG_LOCAL3,
+    "local4": logging.handlers.SysLogHandler.LOG_LOCAL4,
+    "local5": logging.handlers.SysLogHandler.LOG_LOCAL5,
+    "local6": logging.handlers.SysLogHandler.LOG_LOCAL6,
+    "local7": logging.handlers.SysLogHandler.LOG_LOCAL7,
+}
+
+
+def get_txn_id():
+    """Get current transaction ID."""
+    return _txn_id.get()
+
+
+def set_txn_id(txn_id=None):
+    """Set transaction ID, generate if not provided."""
+    if txn_id is None:
+        txn_id = secrets.token_hex(4)
+    _txn_id.set(txn_id)
+    return txn_id
+
+
+def clear_txn_id():
+    """Reset transaction ID to default."""
+    _txn_id.set("-")
+
+
+class TxnIdFilter(logging.Filter):
+    """Inject txn_id into log records."""
+
+    def filter(self, record):
+        record.txn_id = get_txn_id()
+        return True
+
+
+class TxnIdFormatter(logging.Formatter):
+    """Formatter that conditionally includes transaction ID."""
+
+    def __init__(self, fmt_with_txn, fmt_without_txn, datefmt=None):
+        super().__init__(fmt_with_txn, datefmt)
+        self.fmt_with_txn = fmt_with_txn
+        self.fmt_without_txn = fmt_without_txn
+
+    def format(self, record):
+        if hasattr(record, "txn_id") and record.txn_id != "-":
+            self._style._fmt = self.fmt_with_txn
+        else:
+            self._style._fmt = self.fmt_without_txn
+        return super().format(record)
+
+
+def setup_logging(
+    level="INFO",
+    target="stdout",
+    syslog_socket="/dev/log",
+    syslog_facility="daemon",
+    log_file="/var/log/ddns-service.log",
+    log_file_size=52428800,
+    log_versions=5,
+):
+    """
+    Configure global logging.
+
+    Args:
+        level: Log level name (DEBUG, INFO, WARNING, ERROR)
+        target: "stdout", "syslog", or "file"
+        syslog_socket: Path to syslog socket
+        syslog_facility: Syslog facility name
+        log_file: Path to log file (for target="file")
+        log_file_size: Max log file size in bytes before rotation
+        log_versions: Number of backup files to keep
+    """
+    root = logging.getLogger()
+    root.setLevel(getattr(logging, level.upper(), logging.INFO))
+
+    # Clear existing handlers
+    root.handlers.clear()
+
+    txn_filter = TxnIdFilter()
+
+    if target == "syslog":
+        facility = SYSLOG_FACILITIES.get(
+            syslog_facility.lower(),
+            logging.handlers.SysLogHandler.LOG_DAEMON,
+        )
+        handler = logging.handlers.SysLogHandler(
+            address=syslog_socket,
+            facility=facility,
+        )
+        formatter = TxnIdFormatter(
+            "ddns-service[%(process)d]: [%(levelname)s] [%(txn_id)s] %(message)s",
+            "ddns-service[%(process)d]: [%(levelname)s] %(message)s",
+        )
+    elif target == "file":
+        handler = logging.handlers.RotatingFileHandler(
+            log_file,
+            maxBytes=log_file_size,
+            backupCount=log_versions,
+        )
+        formatter = TxnIdFormatter(
+            "%(asctime)s [%(levelname)s] [%(txn_id)s] %(message)s",
+            "%(asctime)s [%(levelname)s] %(message)s",
+            datefmt="%Y-%m-%d %H:%M:%S",
+        )
+    else:
+        handler = logging.StreamHandler()
+        formatter = TxnIdFormatter(
+            "%(asctime)s [%(levelname)s] [%(txn_id)s] %(message)s",
+            "%(asctime)s [%(levelname)s] %(message)s",
+            datefmt="%Y-%m-%d %H:%M:%S",
+        )
+
+    handler.addFilter(txn_filter)
+    handler.setFormatter(formatter)
+    root.addHandler(handler)
+
+
+def disable_logging():
+    """Disable all logging (for CLI quiet mode)."""
+    logging.disable(logging.CRITICAL)
+
+
+def enable_logging():
+    """Re-enable logging."""
+    logging.disable(logging.NOTSET)