[Debug Logs] Enables debug level logs

[IvanBM18]

Overview

As time passes by we have struggled to keep our logs clean, this has been more clear in our issue with too many error logs, which.

As a first step to make logs cleaner im enabling debug level logging worlwide across all loggers(swarming, local, batch, k8s)

Changes

• Adds the debug logging level to our logs.py module.
• Set the new base logging level from logging.INFO -> logging.DEBUG, think of it as the minimum supported logging level, without it our loggers would filter out DEBUG calls.

Test performed

Added a simple log to the task loop in this commit:e61947c, to confirm that its being logged with the correct severity:

https://cloudlogging.app.goo.gl/H1uBTcsR8oY14Vur8

I have some questions following my investigation in dev.

[PauloVLB]

Thanks for working on this.

Because the root logger is set to DEBUG in App Engine and K8s, third-party libraries (like urllib3, requests, google.auth, and google.cloud.logging's background transport dumping "Submitted X logs" on every flush) start dumping all their internal debug logs into Cloud Logging. In dev, this introduces a ton of third-party noise:

Should we silence those third-party loggers so they don't drown out our actual logs?