Oslo Logging Library

8.1.0 · active · verified Sun Apr 12

oslo.log is a Python library that provides standardized logging configuration for OpenStack projects. It offers custom formatters, handlers, and support for context-specific logging, enhancing the standard Python logging module. The current version is 8.1.0 and it's actively maintained by the OpenStack community with regular releases.

Warnings

gotcha When `log_config_append` is specified, all other logging configuration options (e.g., `log_date_format`, `log_file`, `use_syslog`, `default_log_levels`) are ignored. Logging is fully controlled by the specified configuration file.
Fix: If you intend to use a logging configuration file, define all logging settings within that file. If you prefer `oslo.log`'s programmatic or `oslo.config` options, do not set `log_config_append`.
gotcha Changing log format strings can be tricky, especially distinguishing between `logging_context_format_string` and `logging_default_format_string`. `log.set_defaults()` only affects the context-based format string.
Fix: To modify the `logging_default_format_string` (for logs without context), use `CONF.set_override('logging_default_format_string', 'YOUR_FORMAT_STRING')` or define it in your `oslo.config` configuration file under the `[DEFAULT]` section. The `logging_context_format_string` is used when an `oslo.context` object is attached to the log message.
deprecated The existing syslog format used by `oslo.log` is deprecated and will be changed to honor RFC5424 in future versions.
Fix: Be aware that applications relying on the exact syslog message format may need adjustments in the future. Monitor `oslo.log` release notes for details on when the RFC5424 change is implemented. This option is ignored if `log_config_append` is set.

Install

pip install oslo.log Install latest version

Imports

log
```
from oslo_log import log
```
cfg
```
from oslo_config import cfg
```
oslo.log relies on oslo.config for its configuration management.

Quickstart

This quickstart demonstrates the basic setup and usage of oslo.log. It involves importing `cfg` from `oslo_config` to manage configuration options, registering `oslo.log`'s options, and then initializing the logging system with `logging.setup()`. Finally, it shows how to obtain a logger and emit messages at different levels.

import os
from oslo_config import cfg
from oslo_log import log as logging

# Define a configuration group and options (typically done in a separate config file)
CONF = cfg.CONF
CONF.register_group(cfg.OptGroup('DEFAULT'))

# Register oslo.log options (required for oslo.log to pick up config)
logging.register_options(CONF)

# Set up logging for your application
# The 'product_name' is usually your application's name
# The 'version' is your application's version
DOMAIN = os.environ.get('OSLO_LOG_DOMAIN', 'my_app') # Example for context
logging.setup(CONF, DOMAIN, version='1.0.0')

# Get a logger instance
LOG = logging.getLogger(__name__)

# Log messages
LOG.info("This is an informational message.")
LOG.warning("This is a warning message.")
LOG.error("This is an error message.")

# Example of setting a default log level (if not using a config file)
# This would typically be done via a config file or oslo.config options
# For demonstration, setting it programmatically (ensure it's before logging.setup if permanent)
# logging.set_defaults(default_log_levels=['my_app=DEBUG'])

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