Raspberry Pi Init D Script Node App
Once you have developed an app that you want to run on your Raspberry Pi you need to find a way to have it running on the background and possibly to start on boot.
There are different ways to go about it, but a simple and effective one is to use init.d
. You effectively create a deamon that will be running your app in the background and gives you a nice interface to start|stop|restart
your service.
To start, you can use the sample skeleton script distributed with the OS, which you can find at:
$ cat /etc/init.d/skeleton
This script is a template that puts you almost all the way there. However, there are a few things that you might need to be aware of in order to run a node app.
One issue you might face is since you might have to run the script as sudo user then the node binary might not be available- I installed node with the pi user.
Using the script
chmod 755 bin/ledcontroller.sh
sudo cp bin/ledcontroller.sh /etc/init.d/ledcontroller
sudo update-rc.d ledcontroller defaults
ls -l /etc/rc?.d/*ledcontroller
Script
#!/bin/sh
### BEGIN INIT INFO
# Provides: ledcontroller
# Required-Start: $network $syslog
# Required-Stop: $network $syslog
# Default-Start: 2 3 4 5
# Default-Stop: 0 1 6
# Short-Description: ledcontroller
# Description: ledcontroller
### END INIT INFO
# PATH should only include /usr/* if it runs after the mountnfs.sh script
# usr/local/bin/node
PATH=/sbin:/usr/sbin:/bin:/usr/bin
DESC=ledcontroller
NAME=ledcontroller
APP_ROOT=/home/pi/CODE/ledserver/bin
APP_GROUP=pi
APP_USER=pi
DAEMON=/usr/local/bin/node
DAEMON_ARGS="ledcontroller"
PIDFILE=/var/run/$NAME.pid
SCRIPTNAME=/etc/init.d/$NAME
export NODE_ENV={{env}}
# Exit if the package is not installed
[ -x "$DAEMON" ] || exit 0
# Read configuration variable file if it is present
[ -r /etc/default/$NAME ] && . /etc/default/$NAME
# Load the VERBOSE setting and other rcS variables
. /lib/init/vars.sh
# I like to know what is going on
VERBOSE=yes
# Define LSB log_* functions.
# Depend on lsb-base (>= 3.2-14) to ensure that this file is present
# and status_of_proc is working.
. /lib/lsb/init-functions
#
# Function that starts the daemon/service
#
do_start()
{
# Return
# 0 if daemon has been started
# 1 if daemon was already running
# 2 if daemon could not be started
start-stop-daemon --start --quiet \
--chuid $APP_USER:$APP_GROUP --chdir $APP_ROOT --background \
--pidfile $PIDFILE --exec $DAEMON --test > /dev/null \
|| return 1
start-stop-daemon --start --quiet \
--chuid $APP_USER:$APP_GROUP --chdir $APP_ROOT --background \
--make-pidfile --pidfile $PIDFILE --exec $DAEMON -- $DAEMON_ARGS \
|| return 2
# Add code here, if necessary, that waits for the process to be ready
# to handle requests from services started subsequently which depend
# on this one. As a last resort, sleep for some time.
}
#
# Function that stops the daemon/service
#
do_stop()
{
# Return
# 0 if daemon has been stopped
# 1 if daemon was already stopped
# 2 if daemon could not be stopped
# other if a failure occurred
start-stop-daemon --stop --quiet --retry=TERM/30/KILL/5 \
--pidfile $PIDFILE --exec $DAEMON
RETVAL="$?"
[ "$RETVAL" = 2 ] && return 2
# Many daemons don't delete their pidfiles when they exit.
rm -f $PIDFILE
return "$RETVAL"
}
#
# Function that sends a SIGHUP to the daemon/service
#
do_reload() {
#
# If the daemon can reload its configuration without
# restarting (for example, when it is sent a SIGHUP),
# then implement that here.
#
start-stop-daemon --stop --signal 1 --quiet --pidfile $PIDFILE \
--exec $DAEMON
return 0
}
case "$1" in
start)
[ "$VERBOSE" != no ] && log_daemon_msg "Starting $DESC" "$NAME"
do_start
case "$?" in
0|1) [ "$VERBOSE" != no ] && log_end_msg 0 ;;
2) [ "$VERBOSE" != no ] && log_end_msg 1 ;;
esac
;;
stop)
[ "$VERBOSE" != no ] && log_daemon_msg "Stopping $DESC" "$NAME"
do_stop
case "$?" in
0|1) [ "$VERBOSE" != no ] && log_end_msg 0 ;;
2) [ "$VERBOSE" != no ] && log_end_msg 1 ;;
esac
;;
status)
status_of_proc "$DAEMON" "$NAME" && exit 0 || exit $?
;;
reload|force-reload)
log_daemon_msg "Reloading $DESC" "$NAME"
do_reload
log_end_msg $?
;;
restart|force-reload)
log_daemon_msg "Restarting $DESC" "$NAME"
do_stop
case "$?" in
0|1)
do_start
case "$?" in
0) log_end_msg 0 ;;
1) log_end_msg 1 ;; # Old process is still running
*) log_end_msg 1 ;; # Failed to start
esac
;;
*)
# Failed to stop
log_end_msg 1
;;
esac
;;
*)
echo "Usage: $SCRIPTNAME {start|stop|status|restart|force-reload}" >&2
exit 3
;;
esac
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