multistructlog 2.1.0

structlog with multiple simultaneous logging backends

This module is a thin wrapper around Structlog that sets and provides defaults for sending logs to one or more logging destinations with individual formatting per destination.

The API consists of a single function: create_logger().

Args:

logging_config (dict): Input to logging.config.dictConfig

level(logging.loglevel): Overrides logging level for all loggers (not handlers!)

Returns:

log: structlog Logger object

It can be invoked as follows:

logging_config = …

log = multistructlog.create_logger(config, level=logging.INFO)

log.info(‘Entered function’, foo=’bar’)

To create a logging_config dictionary, see these docs:

• https://docs.python.org/2.7/library/logging.config.html#logging.config.dictConfig

• http://www.structlog.org/en/stable/standard-library.html#rendering-using-structlog-based-formatters-within-logging

There are no required arguments to create_logger() - any missing parts of the config will be filled in with defaults that print structured logs to the console.

If you don’t specify a formatters section in your config, three will be created which can be used in handlers:

• json: renders one JSON dictionary per message

• structured: prints structured logs with the structlog.dev.ConsoleRenderer

• structured-color: same as structured but with forced color output

If you don’t specify a handlers section, a handler will be added that logs to console with logging.StreamHandler with format structured at level DEBUG.

If you don’t specify a loggers section, a default logger (empty string) will be created with all items in handlers added to it, with a level of NOTSET (every level printed).

When setting log level, the higher of logging_config['loggers'][*]['level'] and logging_config['handlers'][*]['level'] is used. The level parameter overrides the loggers value of level, not the handlers level.

If the handler’s level is set to DEBUG but the logger’s level is set to ERROR, the handler will be overridden and only log ERROR level messages.

Multistructlog also adds a TRACE log level (integer level 5) that is below “DEBUG” to both standard library Logger and Structlog BoundLogger.

List of standard logging levels:

https://docs.python.org/2.7/library/logging.html#logging-levels

Changelog

1.x versions

• legacy

2.0.0

• Substantial refactor/rewrite

• Cache logger objects

• Add trace levels

2.1.0

• Force color on when using structured-color formatter

• Print timestamp and loglevel by default

• Fix issues with reinitialziaton of logger