rsvlog.sh

#!/bin/sh
# Author: TJ Vanderpoel
# Licence: MIT
# This is a generic 'run' script meant to be linked in a log/ directory
# of a runit, daemontools, s6, or similar service.
# It requires svlogd available in the path.

# If the file './conf' exists, it can modify the behavior
# of the svlogd in these ways:

# SV_LOG_SYSLOG=<anything> (if set, uses syslog)
# SV_LOG_SYSLOG_PRIORITY=daemon.info (default daemon.info)

# If SV_LOG_SYSLOG is unset, these variables are used for the svlogd
# configuration
# USERGROUP=user:group (default rsvlog:adm)
# SV_LOGDIR=/path/to/log (default `basename $(dirname $PWD)`)
# CURRENT_LOG_FILE=filename.log (default 'current')

set -e
if [ $0 != "./run" ]; then
	echo "This script meant to be linked as ./run in a service/log directory only!"
	exit 1
fi
curdir=$(basename $(pwd))
if [ "$curdir" != "log" ]; then
	echo "This script meant to be run from a service/log directory only!"
	exit 1
fi

if [ -f ./conf ]; then
	. ./conf
fi

if [ -n "$SV_LOG_SYSLOG" ]; then
	prio=${SV_LOG_SYSLOG_PRIORITY:-daemon.info}
	echo "Logging to Syslog with priority ${prio}"
	exec logger -p $prio
fi

if [ "x$SV_LOGDIR" != "x" ]; then
	logdir=$SV_LOGDIR
fi

if [ -w /var/log ]; then
	user_group=${USERGROUP:-rsvlog:adm}
	if [ "x$logdir" = "x" ]; then
		logdir=$(basename $(dirname $(pwd)))
	fi
	[ -d "/var/log/$logdir" ] || mkdir -p "/var/log/$logdir"
	[ -L ./main ] || [ -d ./main ] || ln -s "/var/log/$logdir" ./main
	[ -L ./current ] || ln -s main/current
	if [ "x$CURRENT_LOG_FILE" != "x" ]; then
		[ -L "/var/log/$logdir/$CURRENT_LOG_FILE" ] || ln -s current "/var/log/$logdir/$CURRENT_LOG_FILE"
	fi
	usergroup=$(stat -c "%U:%G" "/var/log/$logdir")
	if [ "$usergroup" != "$user_group" ]; then
		chown -R $user_group "/var/log/$logdir"
	fi
	echo Logging as $user_group to /var/log/$logdir
	exec chpst -u $user_group svlogd -t ./main
else
	echo Logging in $PWD
	if [ "x$CURRENT_LOG_FILE" != "x" ]; then
		[ -L "$CURRENT_LOG_FILE" ] || ln -s current "$CURRENT_LOG_FILE"
	fi
	exec svlogd -t ./
fi

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