Hi5Dev

Using Heroku you can privately host your gems in just a couple of minutes. Here’s how.

Start by creating an empty project folder, and add a Gemfile with only the source and ruby version:

1 # File: Gemfile
2 source 'https://rubygems.org'
3 ruby '2.0.0'

Then run bundle to generate Gemfile.lock.

Next, create a Procfile with the following content:

1 # File: Procfile
2 web: gem server -p $PORT

Then set up Git:

1 $ git init .
2 $ git add .
3 $ git commit -m Initial commit

Create a new Heroku app and push your application to Heroku:

1 $ heroku create
2 $ git push heroku master

Then launch your new privately hosted gem server in the browser:

1 $ heroku open

And just like that you have your very own private gem server. Now let’s push a gem to the server.

First you’ll want to create a .gitignore file and add .bundle to it so we don’t end up pushing our local Bundler settings to heroku:

1 $ echo ".bundle" >> .gitignore
2 $ git add .gitignore
3 $ git commit -m Ignoring the .bundle path

Next you’ll need a vendor/cache folder. This is where you’ll place your private .gem files. So go ahead and create that folder now, and copy your gem file into it.

1 $ mkdir vendor
2 $ mkdir vendor/cache
3 $ cp my.gem vendor/cache # replace 'my.gem' with your actual gem file

This is where things can get a little tricky. In order for us to push our gem to Heroku, we need to first run bundle install. However since our gem is going to be privately hosted, Bundler will try and fail to download it from rubygems.org. So we need to cache the gem first so it doesn’t try to download it. Ironically, the way we do that is by using the --no-cache flag. Then you’ll need to run bundle package --all to vendor your gem’s dependencies along with the gem:

1 $ bundle install --no-cache
2 $ bundle package --all

Using bundle --no-cache tells Bundler that the .gem files have already been copied into the vendor/cache folder, and it will install those instead of connecting to rubygems.org. bundle package --all downloads the missing dependencies and copies their .gem files into the vendor/cache folder, thus completing the installation.

It’s a bit confusing, but in the end it’s really only this three step process:

• Copy your private gem’s .gem file into vendor/cache
• Run bundle install --no-cache
• Run bundle package --all

Then of course you’ll need to push those files to Heroku:

1 $ git add .
2 $ git commit -m Installed my private gem
3 $ git push heroku master

Refresh your browser, and you’ll notice that your gem will now be listed.

Now all you have to do to install the private gem in your application is add the URL to your Heroku app that’s hosting the gems to your Gemfile. For example:

1 # File myapp/Gemfile
2 source 'https://rubygems.org'
3 source 'http://private-gem-server.herokuapp.com'
4 
5 gem 'my_private_app'