Monit Configuration

1. INSTALL MONIT
sudo apt-get install monit
sudo nano /etc/monit/monitrc
monit
monit status

2. UNCOMMENT THIS SECTION FROM /etc/monit/monitrc
set httpd port 2812
    use address 12.34.56.789  # only accept connection from localhost
    allow 0.0.0.0/0.0.0.0        # allow localhost to connect to the server and
    allow admin:monit      # require user 'admin' with password 'monit'

monit reload

3. EXAMPLE OF MONITORING NGINX
check process nginx with pidfile /run/nginx.pid
    start program = "/etc/init.d/nginx start"
    stop program = "/etc/init.d/nginx stop"

check process postgresql with pidfile /run/postgresql/9.4-main.pid
    group database
    start program = "/etc/init.d/postgresql start"
    stop  program = "/etc/init.d/postgresql stop"

check process redis-server with pidfile /run/redis_6379.pid
    start program = "/etc/init.d/redis_6379 start"
    stop program = "/etc/init.d/redis_6379 stop"

check process sidekiq
  with pidfile /home/dev/apps/privateholidays_v2/shared/tmp/pids/sidekiq.pid
  start program = "/bin/bash -l -c 'cd /home/dev/apps/privateholidays_v2/current && bundle exec sidekiq --index 0 --pidfile /home/dev/apps/privateholidays_v2/shared/tmp/pids/sidekiq.pid --environment production --logfile /home/dev/apps/privateholidays_v2/shared/log/sidekiq.log --daemon'"
  stop program = "/bin/bash -l -c 'cd /home/dev/apps/privateholidays_v2/current && bundle exec sidekiqctl stop /home/dev/apps/privateholidays_v2/shared/tmp/pids/sidekiq.pid 10'"
  if totalmem is greater than 512 MB for 3 cycles then restart
  if 3 restarts within 5 cycles then timeout
  
* we might have to use sudo before all command

4. CHECK MONIT SYNTAX
monit -t

5. RUNNING ALL OF THE MONITORED PROGRAMS
monit start all

* references : http://richfisher.me/blog/2014/07/18/monit-configuration-for-rails/