Download all gems dependencies

Question

I want to install compass by downloading any required file and taking them to another machine without internet connection. I have downloaded the source package

Answer 1

I did

export GEM_HOME=.
export GEM_PATH=.
gem install --no-ri --no-rdoc --install-dir . <gem>

Answer 2

Hm. That's a little tough. gem dependency will show you dependencies for one gem, but it won't go all the way down the tree.

➔ gem dependency compass
Gem compass-0.10.5
  haml (>= 3.0.4, runtime)

Gem compass-0.10.6
  haml (>= 3.0.4, runtime)

➔ gem dependency haml   
Gem haml-3.0.21
  maruku (>= 0.5.9, development)
  yard (>= 0.5.3, development)

Gem haml-3.0.22
  maruku (>= 0.5.9, development)
  yard (>= 0.5.3, development)

Gem haml-3.0.23
  maruku (>= 0.5.9, development)
  yard (>= 0.5.3, development)

Gem haml-3.0.24
  maruku (>= 0.5.9, development)
  yard (>= 0.5.3, development)

"development" means it's only required if you are developing the gem itself. "runtime" means you need it to use it.

so in this case, the only dependency is haml. if it were a more complicated gem, i don't know a good way to generate the whole tree.

Answer 3

Thats exactly the problem I had.
After searching around a while I found a Solution who works using Bundler https://bundler.io/

Getting Gem with Dependencies:

• Create a new Folder with a File named Gemfile in it.
• Write a Source and the Gem you want to have the dependencys for into the File
• Bsp:

  source "http://rubygems.org"
  gem 'rails', '3.2.1'

• Open a Commandline at this Folder an Execute: bundle install
• This should download and install all Dependencys
• Execute the Command bundle list if you wanna see it
• Execute the Command bundle package
• This should create the Directory Structure vendor/cache
• Inside the cache Directory are now all the Dependencys you need for your gem

Install Gem on Machine without internet connection:

• Copy the cache Folder to the Machine
• Open a Commandline inside the Cache Folder and execute gem install --local Gemname.gem
• Bsp:

  gem install --local rails-3.2.1.gem