Pretty fundamental question but I'm trying to understand how best to use Bundler in a deployment situation.
I'm working on a Sinatra application that has about 20 dependent gems. During development, I'm using RVM with a custom gemset for the application, and I run bundle install to update the gemset in accordance with the gemfile.
When it comes to deployment (manually for now, so I can understand how it all works before using a tool like capistrano), I need to do bundle install --development right? This downloads the gems and places them in vendor/bundle.
My question is what else do I need to do? I'm using Unicorn on the server - do I just bundle exec unicorn ... and everything just works? (i.e. bundler finds the vendor directory and uses the gems from there?)
Should unicorn be a vendored gem in the application or a separate 'system' gem on the server that all applications share?
You need --deployment key, not --development: http://gembundler.com/man/bundle-install.1.html#DEPLOYMENT-MODE
On first run bundler creates config in .bundle directory. You can check it by running bundle config or just cat .bundle/config in project's directory. So bundle exec unicorn is enough since bundler knows where gems are installed. On development machine you can also install gems to arbitrary directory using --path key. For more details see manpage for bundle install (link above or bundle help install).