Hi,
last week I was trying to write my own module to log error_log to
systemd-journal [1] and I've found out that with the current error_log
code, it's not possible to do that properly.
I was able to use "error_log" hook, but there is no way to disable
creation of "ErrorLog" file (One can set it to "/dev/null", but httpd
will still write data to it without any reason). Syslog logger fixes
that by hardcoding syslog methods in log.c/core.c, but I don't think
that's the right thing to do with journald.
Therefore, I've created following patches:
http://people.apache.org/~jkaluza/patches/logging/
Their descriptions should be clear from their names, but I will describe
them briefly here too.
Patch 0001 declares ap_errorlog_provider which can be implemented by
module providing error_log logger. Admin can later define "ErrorLog
provider arg" to choose particular errorlog provider. Old syntax still
works and the change is backward compatible. This patch also removes
syslog logging from log.c (it is moved to newly created mod_syslog.c in
next patch)
Patch 0002 creates mod_syslog.c which uses the new API to implement
syslog logging. It works the same way as the version in log.c I removed
in previous patch, but it's in separate module.
Patch 0003 shows how mod_journald.c can use the existing API. This
module works well with systemd-journal, but unfortunately the
performance of systemd-journal daemon is poor so far [2], but I presume
it will be fixed and the module will be usable for general use in the
future. There is probably no real benefit in accepting this last patch
right now. It's here to only show why the previous two patches are useful.
Note that this is my first bigger patch touching httpd core, so feel
free to correct my possible mistakes... :)
[1] http://0pointer.de/blog/projects/journalctl.html
[2] https://bugzilla.redhat.com/show_bug.cgi?id=963620
[patches] http://people.apache.org/~jkaluza/patches/logging/
Regards,
Jan Kaluza
