#!/bin/sh
#
#     Copyright (C) 1995--2005  Kurt Garloff, SUSE / Novell Inc.
#     Copyright (C) 2012 Ettore Simone, H4T srl, Vignola, Italy.
#
# /etc/init.d/garb
#   and its symbolic link
# /usr/sbin/rcgarb
#          
### BEGIN INIT INFO
# Provides:          garb
# Required-Start:    $local_fs $remote_fs $network
# Should-Start:      $syslog $time $named network-remotefs mysql
# Required-Stop:     $local_fs $remote_fs $network
# Should-Stop:	     $syslog $time $named network-remotefs mysql
# Default-Start:     3 5
# Default-Stop:      0 1 2 6
# Short-Description: Galera Arbitrator
# Description:       Starting with version 0.8.2 Galera comes
#       with an "arbitrator" garbd, a stateless daemon which
#       acts as a lightweight group member and can serve two
#       purposes:
#       - Help to avoid split-brain situation by acting as an
#         odd node
#       - Request a consistent application state snapshot
#       As a Galera cluster member arbitrator accepts all
#       Galera parameters except those prefixed by "replicator".
### END INIT INFO


# Check for missing binaries (stale symlinks should not happen)
# Note: Special treatment of stop for LSB conformance
GARB_BIN=/usr/sbin/garbd
test -x $GARB_BIN || { echo "$GARB_BIN not installed"; 
	if [ "$1" = "stop" ]; then exit 0;
	else exit 5; fi; }

# Check for existence of needed config file and read it
GARB_CONFIG=/etc/sysconfig/garb
test -r $GARB_CONFIG || { echo "$GARB_CONFIG not existing";
	if [ "$1" = "stop" ]; then exit 0;
	else exit 6; fi; }

# Read config
. $GARB_CONFIG

# Check that node addresses are configured
if [ -z "$GALERA_NODES" ]; then
	echo "List of GALERA_NODES is not configured"
	return 6
fi
if [ -z "$GALERA_GROUP" ]; then
	echo "GALERA_GROUP name is not configured"
	return 6
fi

GALERA_PORT=${GALERA_PORT:-4567}

# Find a working node
for ADDRESS in ${GALERA_NODES} 0; do
	HOST=$(echo $ADDRESS | cut -d \: -f 1 )
	PORT=$(echo $ADDRESS | cut -d \: -f 2 )
	PORT=${PORT:-$GALERA_PORT}
	netcat -z $HOST $PORT >/dev/null && break
done
if [ ${ADDRESS} == "0" ]; then
	echo "None of the nodes in $GALERA_NODES is accessible"
	return 1
fi

OPTIONS="-d -a gcomm://$ADDRESS"
[ -n "$GALERA_GROUP" ]   && OPTIONS="$OPTIONS -g $GALERA_GROUP"
[ -n "$GALERA_OPTIONS" ] && OPTIONS="$OPTIONS -o $GALERA_OPTIONS"
[ -n "$LOG_FILE" ]       && OPTIONS="$OPTIONS -l $LOG_FILE"

# Shell functions sourced from /etc/rc.status:
#      rc_check         check and set local and overall rc status
#      rc_status        check and set local and overall rc status
#      rc_status -v     be verbose in local rc status and clear it afterwards
#      rc_status -v -r  ditto and clear both the local and overall rc status
#      rc_status -s     display "skipped" and exit with status 3
#      rc_status -u     display "unused" and exit with status 3
#      rc_failed        set local and overall rc status to failed
#      rc_failed <num>  set local and overall rc status to <num>
#      rc_reset         clear both the local and overall rc status
#      rc_exit          exit appropriate to overall rc status
#      rc_active        checks whether a service is activated by symlinks
. /etc/rc.status

# Reset status of this service
rc_reset

# Return values acc. to LSB for all commands but status:
# 0	  - success
# 1       - generic or unspecified error
# 2       - invalid or excess argument(s)
# 3       - unimplemented feature (e.g. "reload")
# 4       - user had insufficient privileges
# 5       - program is not installed
# 6       - program is not configured
# 7       - program is not running
# 8--199  - reserved (8--99 LSB, 100--149 distrib, 150--199 appl)
# 
# Note that starting an already running service, stopping
# or restarting a not-running service as well as the restart
# with force-reload (in case signaling is not supported) are
# considered a success.

case "$1" in
    start)
	echo -n "Starting Galera Arbitrator "
	## Start daemon with startproc(8). If this fails
	## the return value is set appropriately by startproc.
	/sbin/startproc -u nobody $GARB_BIN $OPTIONS

	# Remember status and be verbose
	rc_status -v
	;;
    stop)
	echo -n "Shutting down Galera Arbitrator "
	## Stop daemon with killproc(8) and if this fails
	## killproc sets the return value according to LSB.

	/sbin/killproc $GARB_BIN
	for ((n=30;n>0;n--)); do
		/sbin/checkproc $GARB_BIN || break
		sleep 1 && echo -n '.'
	done
	if [ $n -eq 0 ]; then
		pkill -9 $GARB_BIN 
	fi

	# Remember status and be verbose
	rc_status -v
	;;
    restart|reload)
	## Stop the service and regardless of whether it was
	## running or not, start it again.
	$0 stop
	$0 start

	# Remember status and be quiet
	rc_status
	;;
    status)
	echo -n "Checking for Galera Arbitrator "
	## Check status with checkproc(8), if process is running
	## checkproc will return with exit status 0.

	# Return value is slightly different for the status command:
	# 0 - service up and running
	# 1 - service dead, but /var/run/  pid  file exists
	# 2 - service dead, but /var/lock/ lock file exists
	# 3 - service not running (unused)
	# 4 - service status unknown :-(
	# 5--199 reserved (5--99 LSB, 100--149 distro, 150--199 appl.)
	
	#service NOTE: checkproc returns LSB compliant status valuesservice.
	/sbin/checkproc $GARB_BIN
	# NOTE: rc_status knows that we called this init script with
	# "status" option and adapts its messages accordingly.
	rc_status -v
	;;
    *)
	echo "Usage: $0 {start|stop|status|restart|reload}"
	exit 1
	;;
esac
rc_exit
