luci-base: err log class for non-err messages

[systemcrash]

ping @jow-

Steps to reproduce:

1. go to: Syslog
2. observe daemon.err log lines like:

Tue Oct  8 18:10:07 2024 daemon.err uhttpd[2772]: [info] luci: accepted login on /admin/blah for root from x.x.x.x

This appears due to dispatch.uc which has:

function syslog(prio, msg) {
	warn(sprintf("[%s] %s\n", prio, msg));
}

So we get daemon.err despite the message electing the info log class. Can this be improved?

Expected behavior:

Correct log class for syslog messages from uhttpd.

Additional Information:

OpenWrt version information from system /etc/openwrt_release

DISTRIB_ID='OpenWrt'
DISTRIB_RELEASE='23.05.5'
DISTRIB_REVISION='r24106-10cc5fcd00'
DISTRIB_TARGET='x86/64'
DISTRIB_ARCH='x86_64'
DISTRIB_DESCRIPTION='OpenWrt 23.05.5 r24106-10cc5fcd00'
DISTRIB_TAINTS=''

[jow-]

Make it printf() instead of warn(sprintf()). Should probably decide based on prio.

[systemcrash]

That was one of the first things I tried but nothing is then emitted to the syslog. 😒

I thought you would know better what to try after that.

[systemcrash]

I'll try printf, maybe I just tried sprintf.

[systemcrash]

No - those don't seem to emit anything. 🤷

[jow-]

Yeah, I recall. It's because procd captures uhttpd's stderr and relays it as daemon.err which is where LuCI's warn() output ends up. stdout is reserved for cgi communication. Not solvable unless you invest time implementing a full blown syslog() binding (some effort) or invoking the external logger util (overhead).