I'm not a major user of rospy, but the log4cxx logger in roscpp is configured via the ROSCONSOLE_CONFIG_FILE environment variable. Should there be something similar to allow setting the config location for Python? Wait a minute, nevermind— there totally is ROS_PYTHON_LOG_CONFIG_FILE. Is this change just allowing yaml in addition to conf as the format?

FYI @paulbovbel

@mikepurvis yes just that. I figured it was simple enough to add and would allow more detailed configuration using recent python 2.7 logging API. Plus we are already using yaml everywhere for configuration in our ROS software so why not for logging as well.

But AFAIK there is no test for this behaviour it and I haven't used it yet, so this patch might need a few days/weeks to mature...

I tested part of that new code (by setting ROS_PYTHON_LOG_CONFIG_FILE to python_logging.yaml in my environment) with this file :

---
version: 1
disable_existing_loggers: False
formatters:
    default:
        format: "[%(name)s][%(levelname)s] %(asctime)s: %(message)s"

handlers:

    rosconsole:
        class: rosgraph.roslogging.RosStreamHandler
        level: DEBUG
        formatter: default
        colorize: True

    roslog:
        class: logging.handlers.RotatingFileHandler
        level: DEBUG
        formatter: default
        filename: os.environ['ROS_LOG_FILENAME']
        maxBytes: 50000000
        backupCount: 4

loggers:

    root:
        level: INFO
        handlers: [roslog]

    rosout:
        level: INFO
        handlers: [rosconsole]
        propagate: yes
        qualname: rosout

I get one error that I didn't have with python_logging.conf :

No handlers could be found for logger "roslaunch"

As well as for my other custom loggers in my code that didn't add NullHandler as explained here : https://docs.python.org/2/howto/logging.html#library-config

So I understand it means that no logger is configured for roslaunch in python_logging.conf, but I don't know what is the behavior in that case, where and how it will send log messages...

We should add a NullHandler into roslaunch.
But do we want to add a specific config for roslaunch logger ?

Or maybe we do not want a NullHandler for roslaunch, since it is not a library after all, and that error is expected.

And we should define (for example) :

• a default console handler for roslaunch in code
• an extra file handler in configuration file (if needed, or even just as an example).

Any idea/advice for this ?

I solved roslaunch warning on my side by adding this to the config :

    roslaunch:
        level: WARNING
        handlers: [rosconsole]
        propagate: no
        qualname: roslaunch