Add a function to send messages to MessageLog

[PiotrRajtar]

It would be useful for tm1py to allow sending messages to the MessageLog, so that they can be easily browsed and picked up by Pulse alerts.

Currently I am doing something similar using an unbound TI, but is not ideal as whitespaces have to be replaced with some other separator, e.g. underscore, otherwise they get removed:

                logging.exception(f"Unable to send values to cube [{log_cube}].")
                self.tm1.processes.execute_ti_code(f"LogOutput('ERROR', 'TM1py_[{path.basename(__file__)}]"
                                                   f"_{type(ex).__name__}__Please_check_[{LOG_FILE}]_for_details.');")

Ideally, the function should be supported as a custom logging handler in the logging module.

[zsoltmoravcsik]

+1 That would be a nice feature, could we maybe leverage the REST API log related endpoints? Maybe just give a simple feature to post via rest API a message log entry like Logoutput in TIs. It would help REST-based application transparency and collect logs in one place which make log tracing simpler for solutions like Pulse or other ELK stack solutions.

[rkvinoth]

@PiotrRajtar I don't think there is a way to add LOGOUTPUT via REST API (I could be wrong).

But the unboundTI way works. The issue with your code is that, execute_ti_code method expects an iterable but you are passing a str. It is trying to convert your str into an iterable and that is why the whitespaces are getting removed.
This should work:

try:
    pass
except Exception as ex:
    logging.exception(f"Unable to send values to cube [{log_cube}].")
    self.tm1.processes.execute_ti_code(lines_prolog=[f"LogOutput('ERROR', 'TM1py [{path.basename(__file__)}] "
                                                     f"{type(ex).__name__} please check [{LOG_FILE}] for details.');"])

I highly recommend the usage of parameter names (lines_prolog) in the code (though it is the only mandatory parameter), as it makes the code more readable.

@MariusWirtz Would it be possible to build a custom method that would take the loglevel and message then write it to the serverlog using TI (we can have the require_admin decorator)?

[MariusWirtz]

Good point @rkvinoth. The function expects an iterable. I oversaw this.
AFAIK we have to use unbound ti processes for writing to the message log.

@rkvinoth please feel free to open a Pull Request!

[gbryant-dev]

@MariusWirtz @rkvinoth If no one is already picking this up, I would be happy to raise a PR for this for my first contribution to TM1py!

Let me know :)

[rkvinoth]

That would be awesome. Currently I'm engaged with other stuff.

Thanks!

[gbryant-dev]

Here's the PR #639 :)

[MariusWirtz]

Closed with #639