A simple example how to run a node service on a server using a custom init.d script (to be able to easily start/stop the service as a daemon) and Monit (to monitor and restart the script if it is terminated).
We assume that node is installed as /usr/local/bin/node and our node service behaves like this:
- The service should be called
node-service - The server script is
/home/node/node-service/server.js - The server listens on port 8000
- Output should be appended to
/var/log/node-service.log
A simple init.d script for the node-service is provided at init.d/node-service.
You may adjust your paths at the beginning:
PATH=/sbin:/usr/sbin:/bin:/usr/bin:/usr/local/bin
DAEMON_ARGS="/home/node/node-service/server.js"
DESC="node.js service"
NODEUSER=node:node
LOCAL_VAR_RUN=/var/run
NAME=node
DAEMON=/usr/local/bin/$NAME
LOGFILE=/var/log/node-service.log
You can start the service with
# /etc/init.d/node-service start
and terminate it with
# /etc/init.d/node-service stop
Note: the server is not restarted if it crashes. This is a bit tricky with SysVinit, see the node-init repository for a solution.
Monit can be used to monitor the service and restart it if it is terminated (e.g. crashes).
On Debian we just have to install the monit package and enable it in /etc/default/monit. On some systems, you also have to add this line to /etc/monit/monitrc:
include /etc/monit/conf.d/*
Basic configuration for Monit is done in /etc/monit/conf.d/basic:
set daemon 30
set logfile /var/log/monit.log
# set mailserver localhost
# set mail-format { from: root@example.com }
# set alert root@example.com
set httpd port 2812 and
use address localhost
allow localhost
This way Monit checks its services every 30 seconds. To be notified about state changes, uncomment the mail* lines.
Monitoring for our service is configured in /etc/monit/conf.d/node-service:
check node-service
with pidfile /var/run/node-service.pid
start program = "/etc/init.d/node-service start"
stop program = "/etc/init.d/node-service stop"
if failed port 8000 protocol HTTP request / with timeout 10 seconds then restart
if 3 restarts within 5 cycles then timeout
This is quite self-explanatory. The service is restarted if it is not reachable via HTTP (or its pidfile is invalid), if it is restarted 3 times in 5*30 seconds, it is marked as timeout and not tried again.
Once Monit is running (after reboot or /etc/init.d/monit start), it starts checking if the node-service is running. If not, it starts the service automatically.
The status can be displayed with
# monit status
which outputs something like
The Monit daemon 5.1.1 uptime: 48m
Process 'node-service'
status running
monitoring status monitored
pid 6832
parent pid 1
uptime 53m
children 0
memory kilobytes 9596
memory kilobytes total 9596
memory percent 0.4%
memory percent total 0.4%
cpu percent 0.0%
cpu percent total 0.0%
port response time 0.001s to localhost:8000/ [HTTP via TCP]
data collected Thu Mar 10 16:25:54 2011
To start/stop the node-service without Monit complaining about it, just use
# monit start node-service
# monit stop node-service
The init.d script is based on the one by Peter Horst on https://gist.github.com/715255
You can find a newer version for init.d at my node-init repository.