format_exc_info should add structured data about the exception to the event_dict about structlog HOT 11 CLOSED

Fwiw, the stdlib's Logger also logs the original exception message, regardless of the message passed to the .exception(...) method.

from structlog.

Okay, it seems this is already (mostly) addressed by #22.

The stdlib's .exception() also includes the original exception message; I can't quickly see whether structlog's emulation does that as well?

from structlog.

Please try and file a bug if it doesn’t. (respectively transform this ticket into that in that case to make use of it :)).

from structlog.

(I’m not 100% sure what you mean so I figure it’s faster if you just test it before I start asking clarification questions and test it then to tell you)

from structlog.

This Python file:

logging.basicConfig()
logger = logging.getLogger(__name__)

try:
    raise ValueError("This is the exception message.")
except ValueError:
    logger.exception("This is the log message.")

shows this output:

ERROR:__main__:This is the log message.
Traceback (most recent call last):
  File "blah.py", line 8, in <module>
    raise ValueError("This is the exception message.")
ValueError: This is the exception message.

As you can see, both the log message and the exception message show up in the log. A similar setup with structlog loses the exception message.

from structlog.

The structlog configuration is from the docs:

    structlog.configure(
        processors=[
            structlog.stdlib.filter_by_level,
            structlog.processors.StackInfoRenderer(),
            structlog.processors.format_exc_info,
            structlog.processors.JSONRenderer(),
        ],
        context_class=dict,
        logger_factory=structlog.stdlib.LoggerFactory(),
        wrapper_class=structlog.stdlib.BoundLogger,
        cache_logger_on_first_use=True,
    )

from structlog.

So, I’ve tested it with

import logging

import structlog


logging.basicConfig()

structlog.configure(
    processors=[
        structlog.stdlib.filter_by_level,
        structlog.processors.StackInfoRenderer(),
        structlog.processors.format_exc_info,
        structlog.processors.JSONRenderer(),
    ],
    context_class=dict,
    logger_factory=structlog.stdlib.LoggerFactory(),
    wrapper_class=structlog.stdlib.BoundLogger,
    cache_logger_on_first_use=True,
)

logger = structlog.get_logger()

try:
    raise ValueError("This is the exception message.")
except ValueError:
    logger.exception("This is the log message.")

And the reformatted output I’m getting is:

{
  "exception": "Traceback (most recent call last):\n  File \"t2.py\", line 22, in <module>\n    raise ValueError(\"This is the exception message.\")\nValueError: This is the exception message.",
  "event": "This is the log message."
}

So the error message clearly is there (the stdlib output is completely within the formatted string), but what you’re saying is that you’d like the exception data in a more structured form?

Right now, format_exc_info really just formats the traceback: https://github.com/hynek/structlog/blob/master/structlog/processors.py#L169

It’s totally thinkable to pull data out of the exception I guess? I’m removing the milestone though because this is a nice but not too important feature (and you can implement it for yourself for now if you want to).

from structlog.

Okay maybe I was just being blind. The original message is part of the formatted traceback, right?

from structlog.

Yes, it should. Scroll to the right above to verify. :) The job of format_exc_info is to emulate the output you would have gotten on the console.

from structlog.

In that case I must've missed
it the first time in the huge json spaghetti on my screen. I'm sorry for the noise.

Hynek Schlawack [email protected] schreef op 10 januari 2015 09:40:00 CET:

Yes, it should. Scroll to the right above to verify. :) The job of
format_exc_info is to emulate the output you would have gotten on the
console.

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from structlog.

I think extracting the actual error message from a stack trace is not that useful anyway. The message will likely not be that useful without the additional info from the stack trace, so I guess the current output is fine.

Closing this issue.

from structlog.