logstash-formatter

0.5.17 verified Mon Apr 27 auth: no python maintenance

A JSON log formatter for logstash, typically used with Python's logging module. Current version 0.5.17. Infrequently updated; last release in 2019.

pip install logstash-formatter

Common errors

error ModuleNotFoundError: No module named 'logstash_formatter' ↓

cause Package not installed or import path incorrect.

fix

Run 'pip install logstash-formatter' and use 'from logstash_formatter import LogstashFormatter'.

error TypeError: __init__() got an unexpected keyword argument 'version' ↓

cause Passing parameters that don't match the constructor signature (e.g., 'version' instead of 'fmt' or 'datefmt').

fix

Check the constructor: LogstashFormatter(fmt=None, datefmt=None, extra=None). Remove unsupported arguments.

error AttributeError: 'LogstashFormatter' object has no attribute '_style' ↓

cause Incompatibility with Python logging internals in newer Python versions (3.8+).

fix

Pin to logstash-formatter==0.5.17 and ensure Python >=3.6. If issues persist, consider switching to python-json-logger.

Warnings

gotcha Message string is automatically included; do not embed JSON in the message itself as it may interfere with parsing. ↓

fix Use the extra parameter to add structured data instead of formatting it into the message string.

gotcha Timestamp defaults to the current time in UTC in ISO8601 format; timezone awareness may cause issues if your logs are not in UTC. ↓

fix Set the 'format' parameter to 'UNIX' or custom format, or ensure your logger's timezone is consistent.

deprecated Python 2 support is effectively abandoned; the library may not install or function correctly on Python 2. ↓

fix Upgrade to Python 3. Use version 0.5.17 on Python 3.6+.

Imports

LogstashFormatter

wrong

from logstash_formatter.formatter import LogstashFormatter

correct

from logstash_formatter import LogstashFormatter

Old import path from earlier versions; now use top-level module.

Quickstart

Basic setup with a stream handler. The extra dict becomes JSON fields.

import logging
from logstash_formatter import LogstashFormatter

handler = logging.StreamHandler()
formatter = LogstashFormatter()
handler.setFormatter(formatter)
logger = logging.getLogger('my_logger')
logger.addHandler(handler)
logger.setLevel(logging.INFO)
logger.info('Hello, logstash!', extra={'custom_field': 'value'})