fix: use the log timestamp when ingesting to loki (#15)

Author: simosho

logging_loki/emitter.py

@@ -46,7 +46,8 @@ def __init__(self,
         props_to_labels: Optional[list[str]] = None,
         level_tag: Optional[str] = const.level_tag,
         logger_tag: Optional[str] = const.logger_tag,
-        verify: Union[bool, str] = True
+        verify: Union[bool, str] = True,
+        replace_timestamp: Optional[bool] = False,
     ):
         """
         Create new Loki emitter.
@@ -75,6 +76,8 @@ def __init__(self,
         self.logger_tag: str = logger_tag
         # verify param to be past to requests, can be a bool (to enable/disable SSL verification) or a path to a CA bundle
         self.verify = verify
+        # Flag to control if the log timestamp should be replaced with the current time
+        self.replace_timestamp = replace_timestamp
 
         self._session: Optional[requests.Session] = None
         self._lock = threading.Lock()
@@ -147,8 +150,7 @@ def build_tags(self, record: logging.LogRecord, line: str) -> Dict[str, Any]:
     def build_payload(self, record: logging.LogRecord, line: str) -> dict:
         """Build JSON payload with a log entry."""
         labels = self.build_tags(record, line)
-        ns = 1e9
-        ts = str(int(time.time() * ns))
+        ts = str(time.time_ns()) if self.replace_timestamp else str(int(record.created * 1e9))
 
         line = json.dumps(record, default=lambda obj: obj.__dict__) if self.as_json else line
 

logging_loki/handlers.py

@@ -71,7 +71,8 @@ def __init__(
         props_to_labels: Optional[list[str]] = None,
         level_tag: Optional[str] = const.level_tag,
         logger_tag: Optional[str] = const.logger_tag,
-        verify: Union[bool, str] = True
+        verify: Union[bool, str] = True,
+        replace_timestamp: Optional[bool] = False,
     ):
         """
         Create new Loki logging handler.
@@ -86,10 +87,10 @@ def __init__(
             level_tag: Label name indicating logging level.
             logger_tag: Label name indicating logger name.
             verify: Either a boolean, in which case it controls whether we verify the server's TLS certificate, or a string, in which case it must be a path to a CA bundle to use.
-
+            replace_timestamp: If enabled, the timestamp in the log line will be replaced with `time.time_ns()`. Be careful when using this option with `batching` enabled, as the logs will be sent in batches, and the timestamp will be the time of the batch, not the time of the log.
         """
         super().__init__()
-        self.emitter = LokiEmitter(url, tags, headers, auth, as_json, props_to_labels, level_tag, logger_tag, verify)
+        self.emitter = LokiEmitter(url, tags, headers, auth, as_json, props_to_labels, level_tag, logger_tag, verify, replace_timestamp=replace_timestamp)
 
     def handleError(self, exc: Exception):  # noqa: N802
         """Close emitter and let default handler take actions on error."""