boolean values in environment variables

[christophlingg]

Some configuration variables are boolean and it was not clear to me how to set those bools from environmental variables which are all strings. Eventually, I found the mapping in the code.

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[kaxil]

It shouldn't matter. the values are read as string by the configparser

[kaxil]

❯ export AIRFLOW__CORE__LOAD_DEFAULT_CONNECTIONS=True
❯ ipython
Python 3.7.4 (default, Aug 13 2019, 15:17:50)
Type 'copyright', 'credits' or 'license' for more information
IPython 7.8.0 -- An enhanced Interactive Python. Type '?' for help.

In [1]: from airflow.configuration import  conf

In [2]: conf.getboolean("core", "load_default_connections")
Out[2]: True

In [3]:
Do you really want to exit ([y]/n)? y
❯ export AIRFLOW__CORE__LOAD_DEFAULT_CONNECTIONS=False
❯ ipython
Python 3.7.4 (default, Aug 13 2019, 15:17:50)
Type 'copyright', 'credits' or 'license' for more information
IPython 7.8.0 -- An enhanced Interactive Python. Type '?' for help.

In [1]: from airflow.configuration import  conf

In [2]: conf.getboolean("core", "load_default_connections")
Out[2]: False

In [3]:

[kaxil]

Check line L330

airflow/airflow/configuration.py

Lines 329 to 341 in 096f5c5

	def getboolean(self, section, key, **kwargs):
	val = str(self.get(section, key, **kwargs)).lower().strip()
	if '#' in val:
	val = val.split('#')[0].strip()
	if val in ('t', 'true', '1'):
	return True
	elif val in ('f', 'false', '0'):
	return False
	else:
	raise AirflowConfigException(
	f'Failed to convert value to bool. Please check "{key}" key in "{section}" section. '
	f'Current value: "{val}".'
	)

[christophlingg]

thanks @kaxil for getting into that. When I set the environmental variables I was not aware that airflow parses booleans that gracefully and supports many variants (1, TRUE, true, t, True, ...). One could avoid concerns by giving an example in the documentation, like I did above.

[kaxil]

Even tRuE should work :) as we convert them to .lower() so it doesn't matter for a user until there is a Typo :)

If you think some docs around that can help ease the confusion, I am happy for you to update the docs in this PR and merge it :)

[christophlingg]

Maybe I was thinking too much like a software developer here. And as the parsing is so clever, people won't have issues.

I will close the PR, thanks for your feedback.