[Ovirt-devel] [PATCH] Redirecting all logs to /var/log/ovirt.log

[Jeff Schroeder]

On Mon, Jul 14, 2008 at 11:57 AM, Chris Lalancette <clalance at redhat.com> wrote:
> Darryl L. Pierce wrote:
>> Given how short our scripts are, I don't see a benefit to inserting a
>> method in between the entry point and the functionality.  However,I do
>> like the failure notice as opposed to just exiting the script. So I've
>> pulled that into the script and replaced all calls to die "message" with:
>>
>> function start () {
>>       wget -q -o "some url" || echo "message" && return 1
>> }
>>
>> I'll have a patch out shortly once I run through tests.
>
> I think what Perry is trying to get at is that it would be nice to both display
> an [ OK ] or [ FAIL ] message at the console (like all of the other init scripts
> do), but to also put more verbose output into a logging directory for debugging.
>   That way, if you see you have a [ FAIL ], you at least have an opportunity to
> debug it.  The other advantage is that you don't have redirects littered
> throughout the code for each individual line, and new code (if and when we need
> it) automatically get logged to the appropriate place.
>
> Oh, one other nit-pick from me; I would name the log something like
> /var/log/ovirt-init.log, to make entirely clear it is the output from the init
> scripts.
My take it it should actually use syslog(3) which by default sends it
to /var/log/messages.
Instead of using output redirection, can you use logger(1)? Even if
you insist on a seperate
logfile, it will do these things for you with "-f".

When you've built out a sizable syslog infrastructure accross your datacenters,
it is nice when important applications such as ovirt actually use it.

For shell scripts, something like:
logger -t ovirt-init -p daemon.$level "message"; exit $RETVAL
...
logger -t ovirt-init -p daemon.warn "Ovirt starting"
logger -t ovirt-init -p daemon.error "Can not start daemon for some reason"

# Not tested, just typed into gmail's web interface.
function log() {
    level=$1
    shift
    message="$*"
    logger -t ovirt-init -p daemon.$level "$message"
}
...

Called via something like:
log warn "This is a warning from ovirt-init"

If you wanted to be really fancy, put a case statement towards the bottom
of the log function that would exit on crit, emerg, panic, and error levels.

What do you think of that?

-- 
Jeff Schroeder

Don't drink and derive, alcohol and analysis don't mix.
http://www.digitalprognosis.com