inanzzz | Controlling Nginx with Supervisor

This example shows us how to control nginx with supervisor so when nginx goes down for whatever reason, supervisor will bring it up again as a "foreground" process not as a "daemon".

Important

Supervisor uses daemon off; to start Nginx. The daemon off; directive tells Nginx to stay in the foreground. The sudo service nginx stop/start/restart commands won't work. For more information read Stack Overflow answer.

Current nginx process

As you can see below, Nginx is running in "daemon on" mode.

$ ps aux | grep nginx
root     17184  0.0  0.1 124968  1420 ?        Ss   16:18   0:00 nginx: master process /usr/sbin/nginx -g daemon on; master_process on;

Setup supervisor

$ sudo nano /etc/supervisor/conf.d/nginx.conf

[program:nginx]
command=/usr/sbin/nginx -g "daemon off;"
autostart=true
autorestart=true
startretries=5
numprocs=1
startsecs=0
process_name=%(program_name)s_%(process_num)02d
stderr_logfile=/var/log/supervisor/%(program_name)s_stderr.log
stderr_logfile_maxbytes=10MB
stdout_logfile=/var/log/supervisor/%(program_name)s_stdout.log
stdout_logfile_maxbytes=10MB

Let supervisor know about new config.

$ sudo supervisorctl reread
nginx: available

Let supervisor start nginx service.

$ sudo supervisorctl update
nginx: added process group

Verify if supervisor started nginx service.

$ sudo supervisorctl
nginx:nginx_00                   RUNNING   pid 18429, uptime 0:01:47
supervisor>

Check

As you can see below, Nginx is running in "daemon off" mode.

$ ps aux | grep nginx
root     18429  0.0  0.9 124968  9932 ?        S    17:20   0:00 nginx: master process /usr/sbin/nginx -g daemon off;

Note

If you want to start/stop a service that is controlled by supervisor, you'll need to use supervisor CLI tool like below.

$ sudo supervisorctl
nginx:nginx_00                   RUNNING   pid 18429, uptime 0:02:17

supervisor> help
default commands (type help ):
=====================================
add    exit      open  reload  restart   start   tail   
avail  fg        pid   remove  shutdown  status  update 
clear  maintail  quit  reread  signal    stop    version

supervisor> stop nginx:nginx_00
nginx:nginx_00: stopped

supervisor> start nginx:nginx_00
nginx:nginx_00: started