Logging in Tethys Apps

[swainn]

• Import logging at the top of the module:

  import logging
  

• Immediately after your imports, get a unique logger for your app, but using the "tethys" namespace so that logs are captured in the Tethys logs/console:

  log = logging.getLogger("tethys.my_first_app")
  

• Use the various logger methods in your code to categorize your log statements:

  • log.info("Some message"): normal operation information messages. Keep these to a minimum to avoid impacting the performance of your server.
  • log.warning("Some message"): minor issues encountered that won't prevent the application from running.
  • log.error("Some message"): known/handled errors that are encountered.
  • log.critical("Some message"): issues that need im
  • log.exception("Some message"): unexpected errors, logs more detailed information about the exception including the traceback in addition to the error that occurred.
  • log.debug("Some message"): verbose information for debugging issues in production. I often convert many of my print statements used for development into debug statements.

• Note that different messages will be logged depending on the log level. The log level for configuring Tethys can be configured in the portal_config.yml

  • See LOGGING setting in http://docs.tethysplatform.org/en/stable/tethys_portal/configuration.html#portal-yaml-keys
  • Tethys logging settings are the same as the Django logging settings, so this is good reading for background: https://docs.djangoproject.com/en/2.2/topics/logging/

• For more information about logging in Python see: https://docs.python.org/3.7/library/logging.html