Basic logging for python invoke local

[chernando]

What did you implement:

Closes #4147

This affects both Python 2.7 and Python 3.6 when you try to use logging.

How did you implement it:

Just force logging module to provide a basic config, check logging.basicConfig. Worthy to mention:

This function does nothing if the root logger already has handlers configured for it.

How can we verify it:

YAML:

service: hello

provider:
  name: aws
  runtime: python2.7

functions:
  hello:
    handler: handler.hello

handler.py

from __future__ import print_function
import logging

logger = logging.getLogger(__name__)
logger.setLevel(logging.INFO)


def hello(event, context):
    print('hello')
    logger.info('world')

    return '!'

Invoking sls invoke local -f hello, before:

No handlers could be found for logger "handler"

hello
"!"

after:

INFO:handler:world

hello
"!"

With Python 3.6 (changing serverless.yml) it fails silently, before:

hello
"!"

after:

INFO:handler:world

hello
"!"

Todos:

• Write tests
• Write documentation
• Fix linting errors
• Make sure code coverage hasn't dropped
• Provide verification config / commands / resources
• Enable "Allow edits from maintainers" for this PR
• Update the messages below

Is this ready for review?: YES
Is it a breaking change?: NO

[RafalWilinski]

Thanks for submitting this Pull Request @chernando 💯

We'll look into it after 1.24 release. We decided to do a "code freeze" until we release 1.24 so we could test it thoroughly.

[horike37]

Thanks @chernando 👍
Great to see working fine.

LGTM 💯