[logback-user] debug output when using Groovy configuration

[Dan Stine]

Hi Ceki,

On 2013-05-10 04:02, ceki wrote:
> Hi Dan,
> 
> Thank you for your detailed message. Answers in-line.
> 
> On 09.05.2013 19:26, sw at stinemail.com wrote:
>> Hi,
>> 
>> Thank you for logback and slf4j. We have found them very useful.
>> 
>> I would like to inquire about debugging output, starting with the
>> intended behavior of the system property logback.debug.  It appears 
>> to
>> have no effect if an application is configured via Groovy.  Setting
>> logback.statusListenerClass does have some effect, though the output 
>> is
>> not as verbose as with XML configuration.  I created a sample project
>> that demonstrates the differences:
>> https://github.com/dstine/logback-debug-groovy.  My experiments use 
>> the
>> latest released version of logback 1.0.12.
> 
> Thank you for going to the trouble of creating this sample project.
> 
>> My first question is, should logback.debug behave the same for both 
>> XML
>> and Groovy configuration?  If yes, my next question is, how would we 
>> fix
>> this?  I see the following code in ConfigurationAction (XML):
> 
> Yes, logback.debug should have the same affect in both config systems.
> 
>> https://github.com/qos-ch/logback/blob/71886409e62533af0bdf1d922a7d66f3818d42db/logback-classic/src/main/java/ch/qos/logback/classic/joran/action/ConfigurationAction.java#L47-L52
>> 
> 
>> It looks like logback.debug is simply a shortcut for adding the 
>> status
>> listener.  Is that correct, or is there anything else at play?  
>> Should
>> we "just" copy this code to ConfigurationDelegate (Groovy), or
>> centralize it somehow?
> 
> Yes, that is correct. The debug attribute is a shortcut for adding the
> OnConsoleStatusListener. Nothing else is at play. Copying to
> ConfigurationDelegate sounds good.

I have submitted an attempt at this change:
https://github.com/qos-ch/logback/pull/124

I had to use GafferConfigurator instead of ConfigurationDelegate.  I 
tried to copy/paste cleanly, but did have to account for the fact that 
(as far as I can see) there is no per-file "debug" attribute in the 
Groovy DSL.

> 
>> Next, the output for Groovy config appears to not include information
>> about configuring loggers, whereas XML config provides this output:
>> 
>> 11:43:58,046 |-INFO in
>> ch.qos.logback.core.joran.action.NestedComplexPropertyIA - Assuming
>> default type ch.qos.logback.classic.encoder.PatternLayoutEncoder] for
>> [encoder] property
>> 11:43:58,078 |-INFO in
>> ch.qos.logback.classic.joran.action.RootLoggerAction - Setting level 
>> of
>> ROOT logger to DEBUG
>> 11:43:58,078 |-INFO in
>> ch.qos.logback.core.joran.action.AppenderRefAction - Attaching 
>> appender
>> named [STDOUT] to Logger[ROOT]
> 
> 
> Information about setting logger levels is obviously beneficial. I am
> surprised to learn that it's missing in Gaffer (the groovy
> configurator).

I added the corresponding info statements in the same pull request:
https://github.com/qos-ch/logback/pull/124

The new messages look like this:
12:46:21,918 |-INFO in 
ch.qos.logback.classic.gaffer.ConfigurationDelegate at 3ea909c7 - Setting 
level of ROOT logger to INFO
12:46:21,928 |-INFO in 
ch.qos.logback.classic.gaffer.ConfigurationDelegate at 2830e58e - Attaching 
appender named [STDOUT] to Logger[ROOT]

> 
>> Last, are there other differences I have not yet noticed?
> 
> There is no strict rule mandating that Joran's (the XML configurator)
> output match that of Gaffer (the groovy configurator) or vice
> versa. If you think useful information is missing or there is too much
> information output by either configurator, do not hesitate to make
> corrections. From what I can see you are already familiar with git. A
> pull request would be the easiest way to send in your fixes.

Okay, thanks for the quick response!  I targeted the pull request at 
the 1.0.x branch, since master seems to be aimed at a future 1.1 
release.  Please let me know if I should do something differently.

While we're talking, I have another question that does not concern 
debug output, but does concern Gaffer.  I found your comment in this 
thread [1] that "file inclusion is not supported by Gaffer 
out-of-the-box".  Is there a standard approach that people use to do 
this?  Is there an open feature request?  We might have bandwidth to 
look into it (no promises) but I'd like to get the lay of the land 
first.

Dan

[1] 
http://logback.10977.n7.nabble.com/Externalized-Logback-configuration-for-web-applications-td3629.html