The following has been tested on Ubuntu 8.10 and CentOS 6.2.

Create the file /etc/init.d/sonar with this content:

#!/bin/sh
#
# rc file for SonarQube
#
# chkconfig: 345 96 10
# description: SonarQube system (www.sonarsource.org)
#
### BEGIN INIT INFO
# Provides: sonar
# Required-Start: $network
# Required-Stop: $network
# Default-Start: 3 4 5
# Default-Stop: 0 1 2 6
# Short-Description: SonarQube system (www.sonarsource.org)
# Description: SonarQube system (www.sonarsource.org)
### END INIT INFO

/usr/bin/sonar $*

Register SonarQube at boot time (Ubuntu, 32 bit):

sudo ln -s $SONAR_HOME/bin/linux-x86-32/sonar.sh /usr/bin/sonar
sudo chmod 755 /etc/init.d/sonar
sudo update-rc.d sonar defaults

Register SonarQube at boot time (RedHat, CentOS, 64 bit):

sudo ln -s $SONAR_HOME/bin/linux-x86-64/sonar.sh /usr/bin/sonar
sudo chmod 755 /etc/init.d/sonar
sudo chkconfig --add sonar