feat: add jsonFormatter

freqtrade/loggers/json_formatter.py

@@ -0,0 +1,63 @@
+import json
+import logging
+
+
+class JsonFormatter(logging.Formatter):
+    """
+    Formatter that outputs JSON strings after parsing the LogRecord.
+
+    @param dict fmt_dict: Key: logging format attribute pairs. Defaults to {"message": "message"}.
+    @param str time_format: time.strftime() format string. Default: "%Y-%m-%dT%H:%M:%S"
+    @param str msec_format: Microsecond formatting. Appended at the end. Default: "%s.%03dZ"
+    """
+
+    def __init__(
+        self,
+        fmt_dict: dict = None,
+        time_format: str = "%Y-%m-%dT%H:%M:%S",
+        msec_format: str = "%s.%03dZ",
+    ):
+        print(fmt_dict)
+        self.fmt_dict = fmt_dict if fmt_dict is not None else {"message": "message"}
+        self.default_time_format = time_format
+        self.default_msec_format = msec_format
+        self.datefmt = None
+
+    def usesTime(self) -> bool:
+        """
+        Look for the attribute in the format dict values instead of the fmt string.
+        """
+        return "asctime" in self.fmt_dict.values()
+
+    def formatMessage(self, record) -> dict:
+        """
+        Return a dictionary of the relevant LogRecord attributes instead of a string.
+        KeyError is raised if an unknown attribute is provided in the fmt_dict.
+        """
+        return {fmt_key: record.__dict__[fmt_val] for fmt_key, fmt_val in self.fmt_dict.items()}
+
+    def format(self, record) -> str:
+        """
+        Mostly the same as the parent's class method, the difference being that a dict is
+        manipulated and dumped as JSON instead of a string.
+        """
+        record.message = record.getMessage()
+
+        if self.usesTime():
+            record.asctime = self.formatTime(record, self.datefmt)
+
+        message_dict = self.formatMessage(record)
+
+        if record.exc_info:
+            # Cache the traceback text to avoid converting it multiple times
+            # (it's constant anyway)
+            if not record.exc_text:
+                record.exc_text = self.formatException(record.exc_info)
+
+        if record.exc_text:
+            message_dict["exc_info"] = record.exc_text
+
+        if record.stack_info:
+            message_dict["stack_info"] = self.formatStack(record.stack_info)
+
+        return json.dumps(message_dict, default=str)