|
|
'''
|
|
|
This library is provided to allow standard python logging
|
|
|
to output log data as JSON formatted strings
|
|
|
'''
|
|
|
import logging
|
|
|
import re
|
|
|
from datetime import date, datetime, time, tzinfo, timedelta
|
|
|
import traceback
|
|
|
import importlib
|
|
|
|
|
|
from inspect import istraceback
|
|
|
|
|
|
from collections import OrderedDict
|
|
|
|
|
|
from ...logging_formatter import _inject_req_id, ExceptionAwareFormatter
|
|
|
from ...ext_json import sjson as json
|
|
|
|
|
|
ZERO = timedelta(0)
|
|
|
HOUR = timedelta(hours=1)
|
|
|
|
|
|
|
|
|
class UTC(tzinfo):
|
|
|
"""UTC"""
|
|
|
|
|
|
def utcoffset(self, dt):
|
|
|
return ZERO
|
|
|
|
|
|
def tzname(self, dt):
|
|
|
return "UTC"
|
|
|
|
|
|
def dst(self, dt):
|
|
|
return ZERO
|
|
|
|
|
|
utc = UTC()
|
|
|
|
|
|
|
|
|
# skip natural LogRecord attributes
|
|
|
# http://docs.python.org/library/logging.html#logrecord-attributes
|
|
|
RESERVED_ATTRS = (
|
|
|
'args', 'asctime', 'created', 'exc_info', 'exc_text', 'filename',
|
|
|
'funcName', 'levelname', 'levelno', 'lineno', 'module',
|
|
|
'msecs', 'message', 'msg', 'name', 'pathname', 'process',
|
|
|
'processName', 'relativeCreated', 'stack_info', 'thread', 'threadName')
|
|
|
|
|
|
|
|
|
def merge_record_extra(record, target, reserved):
|
|
|
"""
|
|
|
Merges extra attributes from LogRecord object into target dictionary
|
|
|
|
|
|
:param record: logging.LogRecord
|
|
|
:param target: dict to update
|
|
|
:param reserved: dict or list with reserved keys to skip
|
|
|
"""
|
|
|
for key, value in record.__dict__.items():
|
|
|
# this allows to have numeric keys
|
|
|
if (key not in reserved
|
|
|
and not (hasattr(key, "startswith")
|
|
|
and key.startswith('_'))):
|
|
|
target[key] = value
|
|
|
return target
|
|
|
|
|
|
|
|
|
class JsonEncoder(json.JSONEncoder):
|
|
|
"""
|
|
|
A custom encoder extending the default JSONEncoder
|
|
|
"""
|
|
|
|
|
|
def default(self, obj):
|
|
|
if isinstance(obj, (date, datetime, time)):
|
|
|
return self.format_datetime_obj(obj)
|
|
|
|
|
|
elif istraceback(obj):
|
|
|
return ''.join(traceback.format_tb(obj)).strip()
|
|
|
|
|
|
elif type(obj) == Exception \
|
|
|
or isinstance(obj, Exception) \
|
|
|
or type(obj) == type:
|
|
|
return str(obj)
|
|
|
|
|
|
try:
|
|
|
return super().default(obj)
|
|
|
|
|
|
except TypeError:
|
|
|
try:
|
|
|
return str(obj)
|
|
|
|
|
|
except Exception:
|
|
|
return None
|
|
|
|
|
|
def format_datetime_obj(self, obj):
|
|
|
return obj.isoformat()
|
|
|
|
|
|
|
|
|
class JsonFormatter(ExceptionAwareFormatter):
|
|
|
"""
|
|
|
A custom formatter to format logging records as json strings.
|
|
|
Extra values will be formatted as str() if not supported by
|
|
|
json default encoder
|
|
|
"""
|
|
|
|
|
|
def __init__(self, *args, **kwargs):
|
|
|
"""
|
|
|
:param json_default: a function for encoding non-standard objects
|
|
|
as outlined in http://docs.python.org/2/library/json.html
|
|
|
:param json_encoder: optional custom encoder
|
|
|
:param json_serializer: a :meth:`json.dumps`-compatible callable
|
|
|
that will be used to serialize the log record.
|
|
|
:param json_indent: an optional :meth:`json.dumps`-compatible numeric value
|
|
|
that will be used to customize the indent of the output json.
|
|
|
:param prefix: an optional string prefix added at the beginning of
|
|
|
the formatted string
|
|
|
:param json_indent: indent parameter for json.dumps
|
|
|
:param json_ensure_ascii: ensure_ascii parameter for json.dumps
|
|
|
:param reserved_attrs: an optional list of fields that will be skipped when
|
|
|
outputting json log record. Defaults to all log record attributes:
|
|
|
http://docs.python.org/library/logging.html#logrecord-attributes
|
|
|
:param timestamp: an optional string/boolean field to add a timestamp when
|
|
|
outputting the json log record. If string is passed, timestamp will be added
|
|
|
to log record using string as key. If True boolean is passed, timestamp key
|
|
|
will be "timestamp". Defaults to False/off.
|
|
|
"""
|
|
|
self.json_default = self._str_to_fn(kwargs.pop("json_default", None))
|
|
|
self.json_encoder = self._str_to_fn(kwargs.pop("json_encoder", None))
|
|
|
self.json_serializer = self._str_to_fn(kwargs.pop("json_serializer", json.dumps))
|
|
|
self.json_indent = kwargs.pop("json_indent", None)
|
|
|
self.json_ensure_ascii = kwargs.pop("json_ensure_ascii", True)
|
|
|
self.prefix = kwargs.pop("prefix", "")
|
|
|
reserved_attrs = kwargs.pop("reserved_attrs", RESERVED_ATTRS)
|
|
|
self.reserved_attrs = dict(list(zip(reserved_attrs, reserved_attrs)))
|
|
|
self.timestamp = kwargs.pop("timestamp", True)
|
|
|
|
|
|
# super(JsonFormatter, self).__init__(*args, **kwargs)
|
|
|
logging.Formatter.__init__(self, *args, **kwargs)
|
|
|
if not self.json_encoder and not self.json_default:
|
|
|
self.json_encoder = JsonEncoder
|
|
|
|
|
|
self._required_fields = self.parse()
|
|
|
self._skip_fields = dict(list(zip(self._required_fields,
|
|
|
self._required_fields)))
|
|
|
self._skip_fields.update(self.reserved_attrs)
|
|
|
|
|
|
def _str_to_fn(self, fn_as_str):
|
|
|
"""
|
|
|
If the argument is not a string, return whatever was passed in.
|
|
|
Parses a string such as package.module.function, imports the module
|
|
|
and returns the function.
|
|
|
|
|
|
:param fn_as_str: The string to parse. If not a string, return it.
|
|
|
"""
|
|
|
if not isinstance(fn_as_str, str):
|
|
|
return fn_as_str
|
|
|
|
|
|
path, _, function = fn_as_str.rpartition('.')
|
|
|
module = importlib.import_module(path)
|
|
|
return getattr(module, function)
|
|
|
|
|
|
def parse(self):
|
|
|
"""
|
|
|
Parses format string looking for substitutions
|
|
|
|
|
|
This method is responsible for returning a list of fields (as strings)
|
|
|
to include in all log messages.
|
|
|
"""
|
|
|
standard_formatters = re.compile(r'\((.+?)\)', re.IGNORECASE)
|
|
|
return standard_formatters.findall(self._fmt)
|
|
|
|
|
|
def add_fields(self, log_record, record, message_dict):
|
|
|
"""
|
|
|
Override this method to implement custom logic for adding fields.
|
|
|
"""
|
|
|
for field in self._required_fields:
|
|
|
log_record[field] = record.__dict__.get(field)
|
|
|
log_record.update(message_dict)
|
|
|
merge_record_extra(record, log_record, reserved=self._skip_fields)
|
|
|
|
|
|
if self.timestamp:
|
|
|
key = self.timestamp if type(self.timestamp) == str else 'timestamp'
|
|
|
log_record[key] = datetime.fromtimestamp(record.created, tz=utc)
|
|
|
|
|
|
def process_log_record(self, log_record):
|
|
|
"""
|
|
|
Override this method to implement custom logic
|
|
|
on the possibly ordered dictionary.
|
|
|
"""
|
|
|
return log_record
|
|
|
|
|
|
def jsonify_log_record(self, log_record):
|
|
|
"""Returns a json string of the log record."""
|
|
|
return self.json_serializer(log_record,
|
|
|
default=self.json_default,
|
|
|
cls=self.json_encoder,
|
|
|
indent=self.json_indent,
|
|
|
ensure_ascii=self.json_ensure_ascii)
|
|
|
|
|
|
def serialize_log_record(self, log_record):
|
|
|
"""Returns the final representation of the log record."""
|
|
|
return "{}{}".format(self.prefix, self.jsonify_log_record(log_record))
|
|
|
|
|
|
def format(self, record):
|
|
|
"""Formats a log record and serializes to json"""
|
|
|
message_dict = {}
|
|
|
# FIXME: logging.LogRecord.msg and logging.LogRecord.message in typeshed
|
|
|
# are always type of str. We shouldn't need to override that.
|
|
|
if isinstance(record.msg, dict):
|
|
|
message_dict = record.msg
|
|
|
record.message = None
|
|
|
else:
|
|
|
record.message = record.getMessage()
|
|
|
# only format time if needed
|
|
|
if "asctime" in self._required_fields:
|
|
|
record.asctime = self.formatTime(record, self.datefmt)
|
|
|
|
|
|
# Display formatted exception, but allow overriding it in the
|
|
|
# user-supplied dict.
|
|
|
if record.exc_info and not message_dict.get('exc_info'):
|
|
|
message_dict['exc_info'] = self.formatException(record.exc_info)
|
|
|
if not message_dict.get('exc_info') and record.exc_text:
|
|
|
message_dict['exc_info'] = record.exc_text
|
|
|
# Display formatted record of stack frames
|
|
|
# default format is a string returned from :func:`traceback.print_stack`
|
|
|
try:
|
|
|
if record.stack_info and not message_dict.get('stack_info'):
|
|
|
message_dict['stack_info'] = self.formatStack(record.stack_info)
|
|
|
except AttributeError:
|
|
|
# Python2.7 doesn't have stack_info.
|
|
|
pass
|
|
|
|
|
|
try:
|
|
|
log_record = OrderedDict()
|
|
|
except NameError:
|
|
|
log_record = {}
|
|
|
|
|
|
_inject_req_id(record, with_prefix=False)
|
|
|
self.add_fields(log_record, record, message_dict)
|
|
|
log_record = self.process_log_record(log_record)
|
|
|
|
|
|
return self.serialize_log_record(log_record)
|
|
|
|
