How to add Nginx as a system service

How to add Nginx as a system service

In this section, we will create a script that converts the Nginx daemon to actual system services. This has two functions: the daemon can be controlled using standard commands, and more importantly, it can be automatically started when the system is started and stopped when the system is shut down.
Nginx download

System V scripts

Most Linux-based operating systems use the System-V style init daemon. In other words, their startup process is managed by a daemon called init.
This daemon runs on the principle of runlevel, which represents the state of the computer. Here is a table representing various run levels:
Runlevel State
0 System is halted
1 Single-user mode (rescue mode)
2 Multiuser mode, without NFS support
3 Full multiuser mode
4 Not used
5 Graphical interface mode
6 System reboot

About init script

An init script (also known as a service startup script or even a sysv script) is a shell script that meets certain standards. The script controls the daemon application through commands such as start, stop, and others. First, when the computer starts, the init daemon will run the script using the start parameter. Another possibility is to execute the script manually from the shell:
[root@example.com ~]# service nginx start
Or if your system does not have a service command:
[root@example.com ~]# /etc/init.d/nginx start

Nginx init script

/etc/init.d/nginx:

Debian-based distribution
#! /bin/sh


### BEGIN INIT INFO
# Provides: nginx
# Required-Start: $all
# Required-Stop: $all
# Default-Start: 2 3 4 5
# Default-Stop: 0 1 6
# Short-Description: starts the nginx web server
# Description: starts nginx using start-stop-daemon
### END INIT INFO

PATH=/opt/bin:/opt/sbin:/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin
DAEMON=/opt/sbin/nginx
NAME=nginx
DESC=nginx

test -x $DAEMON || exit 0

# Include nginx defaults if available
if [ -f /etc/default/nginx ] ; then
. /etc/default/nginx
fi

set -e

case "$1" in
start)
echo -n "Starting $DESC: "
start-stop-daemon --start --quiet --pidfile /var/run/nginx.pid \
--exec $DAEMON -- $DAEMON_OPTS
echo "$NAME."
;;
stop)
echo -n "Stopping $DESC: "
start-stop-daemon --stop --quiet --pidfile /var/run/nginx.pid \
--exec $DAEMON
echo "$NAME."
;;
restart|force-reload)
echo -n "Restarting $DESC: "
start-stop-daemon --stop --quiet --pidfile \
/var/run/nginx.pid --exec $DAEMON
sleep 1
start-stop-daemon --start --quiet --pidfile \
/var/run/nginx.pid --exec $DAEMON -- $DAEMON_OPTS
echo "$NAME."
;;
reload)
echo -n "Reloading $DESC configuration: "
start-stop-daemon --stop --signal HUP --quiet --pidfile /var/run/nginx.pid \
--exec $DAEMON
echo "$NAME."
;;
*)
N=/etc/init.d/$NAME
echo "Usage: $N {start|stop|restart|force-reload}" >&2
exit 1
;;
esac

exit 0
Red Hat-based distribution
#!/bin/sh

#
# nginx - this script starts and stops the nginx daemon
#
# chkconfig: - 85 15
# description: NGINX is an HTTP(S) server, HTTP(S) reverse \
# proxy and IMAP/POP3 proxy server
# processname: nginx
# config: /etc/nginx/nginx.conf
# config: /etc/sysconfig/nginx
# pidfile: /var/run/nginx.pid

# Source function library.
. /etc/rc.d/init.d/functions

# Source networking configuration.
. /etc/sysconfig/network

# Check that networking is up.
[ "$NETWORKING" = "no" ] && exit 0

nginx="/usr/sbin/nginx"
prog=$(basename $nginx)

NGINX_CONF_FILE="/etc/nginx/nginx.conf"

[ -f /etc/sysconfig/nginx ] && . /etc/sysconfig/nginx

lockfile=/var/lock/subsys/nginx

make_dirs() {
# make required directories
user=`$nginx -V 2>&1 | grep "configure arguments:" | sed 's/[^*]*--user=\([^ ]*\).*/\1/g' -`
if [ -z "`grep $user /etc/passwd`" ]; then
useradd -M -s /bin/nologin $user
fi
options=`$nginx -V 2>&1 | grep 'configure arguments:'`
for opt in $options; do
if [ `echo $opt | grep '.*-temp-path'` ]; then
value=`echo $opt | cut -d "=" -f 2`
if [ ! -d "$value" ]; then
# echo "creating" $value
mkdir -p $value && chown -R $user $value
fi
fi
done
}

start() {
[ -x $nginx ] || exit 5
[ -f $NGINX_CONF_FILE ] || exit 6
make_dirs
echo -n $"Starting $prog: "
daemon $nginx -c $NGINX_CONF_FILE
retval=$?
echo
[ $retval -eq 0 ] && touch $lockfile
return $retval
}

stop() {
echo -n $"Stopping $prog: "
killproc $prog -QUIT
retval=$?
echo
[ $retval -eq 0 ] && rm -f $lockfile
return $retval
}

restart() {
configtest || return $?
stop
sleep 1
start
}

reload() {
configtest || return $?
echo -n $"Reloading $prog: "
killproc $nginx -HUP
RETVAL=$?
echo
}

force_reload() {
restart
}

configtest() {
$nginx -t -c $NGINX_CONF_FILE
}

rh_status() {
status $prog
}

rh_status_q() {
rh_status >/dev/null 2>&1
}

case "$1" in
start)
rh_status_q && exit 0
$1
;;
stop)
rh_status_q || exit 0
$1
;;
restart|configtest)
$1
;;
reload)
rh_status_q || exit 7
$1
;;
force-reload)
force_reload
;;
status)
rh_status
;;
condrestart|try-restart)
rh_status_q || exit 0
;;
*)
echo $"Usage: $0 {start|stop|status|restart|condrestart|try-restart|reload|force-reload|configtest}"
exit 2
esac
Pay attention to modify the Nginx path in the script.

Active Nginx init script

Add execute permission:
[root@example.com ~]# chmod +x /etc/init.d/nginx
Debian-based distribution
[root@example.com ~]# update-rc.d -f nginx defaults
Red Hat-based distribution
[root@example.com ~]# chkconfig nginx on