FreeBSD_node_monit.md

FreeBSD 10 Nodejs setup with nginx, mongodb, redis and monit

This my receipe for installing a complete nodejs server on FreeBSD 10. The parameters used in this configuration are for a very small private server that I use for demo purpose only, so for a production server, you should somehow set the limits in pair with your ressources.

I use monit so I don't have to write rc scripts for node and it should take care of process lifecycle management for me. Alternatives exists such as supervisord or circus.

Installing mongodb

• run pkg install mongodb to install the server.
• Create a dirctory for mongo to store it's db :

mkdir -p /path/to/mongo/db
chown -R mongodb /path/to/mongo/db

• edit/create /usr/local/etc/mongodb.conf (see mongo config page for more options):

port = 27017
bind_ip = 127.0.0.1 # do not communicate with the external world
maxConns = 50 # you may want more
objcheck = true
dbpath = /path/to/mongo/db
noauth = true

Installing Redis

• run pkg install redis
• If you don't want redis to save on the disk, comment the lines starting with save in: /usr/local/etc/redis.conf

Installing Nginx

• run pkg install nginx
• edit: /usr/local/etc/nginx/nginx.conf, mine looks like that:

user  www;
worker_processes  1;

events {
    worker_connections  128;
    use kqueue;
}

http {
    include       		mime.types;
    default_type  		application/octet-stream;
    sendfile       		on;
    keepalive_timeout  	60;
    tcp_nopush     		on;
    server_tokens 		off;
    charset 			utf-8;
    gzip 				on;
    gzip_min_length 	1000;
    gzip_proxied 		any;
    
    server {
    	listen       		80;
    	server_name  		mydomain.com;
    	
    	location /assets/ {
            autoindex 			on;
            access_log  		off;
            log_not_found 		off;
            alias 				/path/to/node/assets/;
        }
        
        location / {
            try_files 			$uri @node;
        }
        
        location @node {
            proxy_pass  		http://localhost:3000; # set correct node port
            proxy_redirect 		off;
            proxy_buffering 	off;

            proxy_set_header	Host			   host;
            proxy_set_header 	X-Real-IP          $remote_addr;
            proxy_set_header  	X-Forwarded-Proto  https;
            proxy_set_header 	X-Forwarded-Ssl    on;
            proxy_set_header 	X-Forwarded-For    $proxy_add_x_forwarded_for;
        }
   	}
}
    

Installing NodeJS

• run pkg install node npm
• do an npm install in your node project directory.
• monit requires processes to create a pid file. By default node doesn't, but we can wrap node calls in a script (cf monit wiki) create the following startup script somewhere:

#!/usr/local/bin/bash

 case $1 in
    start)
       echo $$ > /var/run/node/node.pid;
       cd /path/to/node/app
       exec /usr/local/bin/node index.js
       ;;
     stop)  
       kill `cat /var/run/node/node.pid` ;;
     *)  
       echo "usage: node.sh {start|stop}" ;;
 esac
 exit 0

• make it executable chmod 755 /path/to/node/startup/script
• create node pid directory and set permission (node will run wtih user www)

mkdir /var/run/node
chown www /var/run/node 

Installing Monit

• run pkg install monit
• create a monitrc file: touch /usr/local/etc/monitrc
• edit the file (you can find inspiration there)

set daemon  60 with start delay 240
set pidfile /var/run/monit.pid
set idfile /var/.monit.id
set statefile /var/.monit.state

set httpd port 2812 and
 	use address localhost  # only accept connection from localhost
    allow localhost        # allow localhost to connect to the server and
    allow admin:monit      # require user 'admin' with password 'monit'

check system myhost.mydomain.com
    if loadavg (1min) > 4 then alert
    if loadavg (5min) > 3 then alert
    if memory usage > 75% then alert
    if cpu usage (user) > 70% then alert
    if cpu usage (system) > 30% then alert
    if cpu usage (wait) > 20% then alert

check process nginx with pidfile /var/run/nginx.pid
    start program = "/usr/local/etc/rc.d/nginx onestart"
    stop program = "/usr/local/etc/rc.d/nginx stop"

check process mongod with pidfile /var/db/mongodb/mongod.lock
	start program = "/usr/local/etc/rc.d/mongod onestart"
	stop program = "/usr/local/etc/rc.d/mongod stop"
	
check process redis with pidfile /var/run/redis/redis.pid
	start program = "/usr/local/etc/rc.d/redis onestart"
	stop program = "/usr/local/etc/rc.d/redis stop"

check process nodejs with pidfile /var/run/node/node.pid
	start program = "/path/to/node/startup/script start" uid www
	stop program = "/path/to/node/startup/script stop" uid www
	if failed port 3000 protocol HTTP
        request /
        with timeout 10 seconds
        then restart

• set root only permission on monitrc: chmod 600 /usr/local/etc/monitrc
• add monit_enable="YES" at the end of /etc/rc.conf
• start monit: sh /usr/local/etc/rc.d/monit start
• to connect to monit web interface, proxy your connection to the host: ssh -L 2812:localhost:2812 hostname then in your browser check localhost:2812