How to fix monit: error connecting to the monit daemon

When you run:

monit status

or

monit summary

and you get

monit: error connecting to the monit daemon

And you are sure monit is running from

ps -A | grep monit

or

service monit status

You need to check Monit HTTP interface is enable. It’s used by the command line tools as well as human being.

In /etc/monit.conf or /etc/monit/monitrc, uncomment the following:

set httpd port 2812 and
use address localhost
allow localhost

and restart monit with

service monit restart