I was wondering if apt-get/dpkg packages (.deb's) manage downtime at all when updating?
For example, when updating
nginx (assuming it's already installed) via
sudo apt-get install nginx, it looks to me like there isn't any downtime.
If that's true, I want to transfer this ability to deploying a PHP application via deb files. I'd normally do a Capistrano-style deployment (build the site, get it onto a web server, and swap the old code with the new code via symlinks).
If instead I install my built application with a .deb package, should I also use a symlinking strategy to minimize downtime or will this install/update the package in a way that already minimizes this?
Assume the .deb package is just replacing code files and then calling a post-install script to reload the application gateway (php-fpm, gunicorn, unicorn, phusion, whatever the app gateway happens to be).