John Dennis wrote:
On 04/16/2012 04:15 PM, Rob Crittenden wrote:
John Dennis wrote:
On 04/16/2012 01:31 PM, Rob Crittenden wrote:
John Dennis wrote:
On 04/13/2012 06:25 AM, Petr Viktorin wrote:
When the utility sets logging to console, the extra log message gets
printed out there. I agree this isn't optimal.
Attached patch removes the console log handler before logging the
result.


I read through log_manager, and found that I can do this more cleanly
with remove_handler.

John, is this a good use of the API?

The problem you're trying to correct is that under some
circumstances a
log message is emitted twice to the console, right?

Removing the console handler fees like the wrong solution, it's a
pretty
big hammer, you have to know when to remove it and once removed any
expectation that messages will appear on the console will be untrue.

Can you give me a brief explanation as to why you're getting duplicate
messages on the console. I wonder if there isn't a better way to
handle
the problem which isn't so invasive and potentially hidden.

Or is the issue you don't want a console handler at all? If that's the
case then maybe we should provide a configuration that does not create
one, that way it will be explicit and obvious there is no console
handler.

FWIW, the current configuration of logging is historical dating
back to
the beginning of the project. When I added the log manager the intent
was to fix deficiencies in logging, not to modify the existing
behavior.
I wasn't clear to me the existing configuration was ideal. If you're
hitting problems because of the existing configuration perhaps we
should
look at the historical configuration and ask if it needs to be
modified.

This patch is standardizing logging the final disposition of a
number of
commands. Currently is must be inferred.

The problem is that some commands have had this disposition added but
open no log files so some error messages are being displayed twice and
in log format.

I think the easiest solution would simply be to scale this back to only
those commands that open a log file at all.

You say "command" but command is a loaded word :-) I presume you mean
command line utility and not an IPA Command object. The reason I'm
drawing this distinction is because the environment Commands execute in
are not supposed to change once api.bootstrap() has completed.

Who or what is aggregating the final disposition of a number of
commands? The reason I ask is because the log_mgr object is global and
deleting a handler from a global resource to satisfy a local need may
have unintentional global side effects. How is the aggregation
accomplished?



This patch is in the context of the command-line utilities like
ipa-server-install, ipa-client-install, etc. and not the ipa tool. Some
of them initialize the api, some do not.

This is exactly the type of problem I'm concerned about, a conflict over
who owns the logging configuration.

These multiple potential "owners" of a global configuration is what lead
me to introduce the "configure_state" attribute of the log manager, to
disambiguate who is in control and who initialized the configuration. In
fact bootstrap() in plugable.py explicitly examines the configure_state
attribute of the log_manager and if it's been previously configured (for
example because the api was loaded by a command line utility that has
configured it's own logging) it then defers to the logging configuration
established by the environment it's being run in (in other words if a
command line utility calls standard_logging_setup() before loading the
api it wins and the logging configuration belongs to the utility, not
the api).

All of this is to say that isolated code that reaches into a global
configuration and takes an axe to it and chops out a significant part of
the configuration that someone else may have established without them
knowing about it feels wrong.

I suspect there is some deeper problem afoot and unilaterally chopping
out the console handler is not addressing the fundamental problem and
likely introduces a new one. But I really need to look at the specific
instances of the problem, maybe if I dig through the history of this
patch review more carefully I'll discover it, but if someone wants to
chime in an point me at the exact issue that would be great :-)

Like I've said, this is a non-issue in this case. Those utilities that do not open a log simply don't need to call this log_on_exit function.

Any remaining logging issues should be logged as a ticket.

I think you're overstating the logging problem in general though. Basically we just want a way to override the default log that the API chooses. So the API bootstrap() call defers to the user if logging has already been configured. It is the responsibility of the developer to know when to do what but since there is less than a half dozen exceptions I don't think this is worth a significant time investment.

At some point we may rewrite all of these utilities to use the API itself at which time this problem will simply go away.

rob

_______________________________________________
Freeipa-devel mailing list
Freeipa-devel@redhat.com
https://www.redhat.com/mailman/listinfo/freeipa-devel

Reply via email to