Using Supervisor to Run and Monitor your Applications
31 Jan 2017It’s been a while I have been using Supervisor to run my apps. It’s a great little tool for running and monitoring processes on UNIX-like operating systems. It provides you simple simple, centralized interface to all your applications running on a box. Using Web Interface, you can see health and logs of the applications without even logging in in the box. Also best part about using Supervisor is it’s ease of usage and configuration.
Installation
sudo apt-get install -y supervisor
Configuration
/etc/supervisor/supervisor.conf
[include]
files = /etc/supervisor/conf.d/*.conf
# Enable Web Interface
[inet_http_server]
port = 9001
username = user # Basic auth username
password = pass # Basic auth password
Syntax
[program:nodehook] - Define the program to monitor. We'll call it "nodehook".
command - This is the command to run that kicks off the monitored process. We use "node" and run the "http.js" file. If you needed to pass any command line arguments or other data, you could do so here.
directory - Set a directory for Supervisord to "cd" into for before running the process, useful for cases where the process assumes a directory structure relative to the location of the executed script.
autostart - Setting this "true" means the process will start when Supervisord starts (essentially on system boot).
autorestart - If this is "true", the program will be restarted if it exits unexpectedly.
startretries - The number of retries to do before the process is considered "failed"
stderr_logfile - The file to write any errors output.
stdout_logfile - The file to write any regular output.
user - The user the process is run as.
environment - Environment variables to pass to the process.
Example Configuration
/etc/supervisor/conf.d/node-chada-chutkila.conf
[program:node-chadachutkila]
command=node /home/art/apps/chada-chutkila/app.js
directory=/home/art
autostart=true
autorestart=true
startretries=3
stderr_logfile=/var/log/art/chada-chutkila.err.log
stdout_logfile=/var/log/art/chada-chutkila.out.log
user=art
environment=SECRET_PASSPHRASE='this is secret',SECRET_TWO='another secret'
Running Supervisor
sudo service supervisor start
Supervisor Configuration Structure
supervisor/
├── conf.d
│ └── digi-marketplace-node.conf
└── supervisord.conf
Controller Processes
Reread Configuration and Reload It
supervisorctl reread
supervisorctl update
Controlling Tool
supervisorctl
Start / Stop Processess
supervisorctl start <processName>
supervisorctl stop <processName>