Monit, Nginx and multiple check types.

nginx

# /etc/monit/conf.d/nginx
check program nginx-http with path "/etc/monit/bin/nginx-check.sh"
  group www
  group nginx
  start program = "/bin/true"                   # Prevent duplicate service starts.
  stop program = "/usr/sbin/service nginx stop" # We don't care if it tries to kill nginx multiple times. :)
  if status != 0 then restart # or alert, or whatever
  depends on nginx-pid # Don't even try to run until the pidfile is there.

check process nginx-pid with pidfile "/run/nginx.pid"
  group www
  group nginx
  start program = "/usr/sbin/service nginx start"
  stop program = "/usr/sbin/service nginx stop"

nginx-check.sh

#!/bin/bash -e

URL="http://127.0.0.1/some/status-check/path"

# Hit the above URL:
# - Follow redirects
# - Hide output, except for the HTTP status code
CODE=$(/usr/bin/curl -sL -w "%{http_code}" -o /dev/null "$URL")

# Two "success" status codes:
#   200: Success all the way through to the Ruby app server.
#   502: We're up, but the backend is down; nothing Nginx can do about that.
[[ "$CODE" == "200" || "$CODE" == "502" ]] && exit 0 || exit 1