CDK: implement custom logging formatter to obfuscate secrets

[keu]

Tell us about the problem you're trying to solve

Currently, we have multiple ways to expose credentials in logs (info, exceptions, tests)

Describe the solution you’d like

The only real way to secure credentials is to control logging output with a logging Formatter attached to the root logger.
This handler will get the connector's config and will replace all occurrence of values from fields marked as secret.

class SecureFormatter(logging.Formatter):
    """ Custom formatter to prevent secrets leaking
    """
    def format(self, record: 'logging.LogRecord') -> str:
        msg = super().format(record)
        for secret in secrets:
            msg = msg.replace(secret, '***')
        return msg

Describe the alternative you’ve considered or used

do manually

┆Issue is synchronized with this Asana task by Unito

[eliziario]

Scoping Report

• Implement the suggested implementation

• Figure out how to initialize the list of secrets for a given exec context

• Create tests for scenarios: normal log statements, exceptions

#1279