I really like supervisord for long-running process management. It is Python, so it is easy to install and it is easy to script with tools like Fabric. Lately I’ve been deploying smaller Django/WSGI sites with Green Unicorn behind Nginx proxied over a Unix socket which makes for a nice little setup on shared hosting and RAM starved VPSes.
After installing supervisord with something like
sudo easy_install supervisor, you’ll want to make sure it runs after you reboot your machine (and gets restarted in case it crashes). If you are on a Linux system with upstart (and have root access), you can bypass the ugly init scripts and use this simple file placed in
/etc/init/supervisord.conf to manage your supervisord process:
description "supervisord" start on runlevel  stop on runlevel [!2345] respawn exec /usr/local/bin/supervisord --nodaemon --configuration /etc/supervisord.conf
Now that it is in upstart, you can start it with the command
sudo start supervisord.
If you are on shared hosting, you probably won’t have permissions to do this, but if you have access to
cron, you can make sure it gets started in case the server reboots by adding this to your cron jobs:
@reboot /my/path/to/supervisord -c /my/path/to/supervisord.conf 2>&1
In the event supervisord crashes or is killed off by a sysadmin, you’re out of luck. If this happens, you’ll want to look into having a cron job periodically poll the process pid to see if it is still alive and restart it if it is not. I haven’t needed this (yet), so that is left as an exercise for the reader :)