airflow/utils/log/json_formatter.py

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"""json_formatter module stores all related to ElasticSearch specific logger classes"""

import json
import logging

from airflow.utils.helpers import merge_dicts


class JSONFormatter(logging.Formatter):
    """JSONFormatter instances are used to convert a log record to json."""

    # pylint: disable=too-many-arguments
    def __init__(self, fmt=None, datefmt=None, style='%', json_fields=None, extras=None):
        super().__init__(fmt, datefmt, style)
        if extras is None:
            extras = {}
        if json_fields is None:
            json_fields = []
        self.json_fields = json_fields
        self.extras = extras

    def usesTime(self):
        return self.json_fields.count('asctime') > 0

    def format(self, record):
        super().format(record)
        record_dict = {label: getattr(record, label, None) for label in self.json_fields}
        merged_record = merge_dicts(record_dict, self.extras)
        return json.dumps(merged_record)