How to run a ruby script within bundler context?

Question

I have a Ruby script called foo.rb, and I want to run it within the context of the bundler environment. How?

bundle exec foo.rb doesn't work, because exec expects a shell script.

score 106 · Accepted Answer · answered Oct 31 '11 at 19:25

106

Pass the script name to the ruby command:

bundle exec ruby script_name

If you also want the Rails environment:

bundle exec rails runner script_name

answered Oct 31 '11 at 19:25

Dave Newton

2

Wow, that was pretty obvious in retrospect. – Michiel de Mare Oct 31 '11 at 19:57
4

@MichieldeMare It's like why everything is in the last place you look--because you stop looking ;) – Dave Newton Oct 31 '11 at 19:59

score 4 · Answer 2 · answered Apr 21 '17 at 23:26

4

For instance, I wanted to use the same version of Rubocop as my Rails app and not the latest system one, so doing this in a script:

require 'bundler'
Bundler.require

# ...

Allowed me to use my app's version of rubocop.

answered Apr 21 '17 at 23:26

Dorian

score 1 · Answer 3 · answered Aug 25 '17 at 14:12

1

You can just make it a script - add

#!/usr/bin/env ruby

to the start of the file, and make it executable. Then bundle exec foo.rb will work as expected.

(This is on unix or OSX - not sure about Windows)

Also see https://coderwall.com/p/kfyzcw/execute-ruby-scripts-directly-without-bundler-exec for how to run ruby scripts with bundled dependencies, without needing bundle exec

answered Aug 25 '17 at 14:12

Korny

If you are using RVM I believe this does not work. I think it is loading ruby in the global or local context, not in the RVM context. And you have to use `bundle exec ruby script_name` in order to have it run in the RVM context. – John C. Feb 27 '21 at 22:53

score 0 · Answer 4 · answered Feb 17 '21 at 18:25

If you want to create a script that you can run in bundle context within a project, you can invoke Bundler programmatically. E.g., given a project:

foo
├── Gemfile
└── bar
    └── baz.rb

you can put the following at the top of baz.rb to give it access to the gems in the Gemfile:

#!/usr/bin/env ruby

ENV['BUNDLE_GEMFILE'] ||= File.expand_path('../Gemfile', __dir__)
require 'bundler/setup'

# ...etc.

With that, you can invoke the script directly without using bundle exec, and you also don't have to invoke it from within the project directory.

4 Answers4