I am planning on using Rubber to deploy a Rails app on Amazon EC2. Do I need to install Ruby, Rails, Postgres, Nginx and Unicorn on the EC2 server before running Rubber? Or does Rubber do all of these installations on EC2? Please advise. Thanks.
Rubber is essentially a capistrano plugin to automate deployments to amazon EC2. You don't have to manually install any of these packages. Rubber will install them for you (in the bootstrap phase), all you need to do is find the right recipe (template). You can find the list of recipes from the rubber's github page. https://github.com/rubber/rubber/tree/master/templates For the exact configuration that you mentioned, the following template should work. complete_unicorn_nginx_postgresql