Why isn't bundle run with "--local" on rails new generator?

rubyonrails-core
1

Creating a new Rails app nowadays in my computer with Bundler-pre takes about 6s only for running "bundle install" in the end of the new generator...

We create a new app instantaneously in Rails 1 and 2.

Shouldn't Bundler try to see if the local dependencies do suffice before trying to ping rubygems.org?

For most cases you'll already have all dependencies locally.

Just try:

rails new empty --skip-bundle cd empty bundle install --local

And you'll see how much faster it is.

But it won't work if you run "rails new empty -d postgres" and don't have postgres already installed.

So, shouldn't Bundler try to resolve locally first by default and then use the normal method with the requests to rubygems.org?

2

The reason this happens is that when you run bundle install without a Gemfile.lock (the case in a new Rails app), bundler checks with rubygems.org to see if there are any new versions available. For instance, it is possible that you have an old version of coffee-script on your system. Calling bundle install without a Gemfile.lock means “make sure to get the latest versions of my gems that are available.” When you use --local, it means “I assert that the gems are all available locally, and I want you to use them even if there may be newer ones available.”

Using --local will not work for a new app on a new system, because there are items in the default Gemfile that are not actual dependencies of Rails. If --local reliably worked, you would not need to run bundle install at all. This is because if Bundler sees that there is no Gemfile.lock when you require “bundler/setup”, it tries to satisfy the dependencies from your local gems. Unfortunately, it will not always work.

Yehuda Katz (ph) 718.877.1325

3

Hi Yehuda, thanks for your response.

I understand what you've said, but what I'm suggesting is that

Bundler could try to resolve all dependencies with local gems first before checking rubygems.org.

For instance, if there's currently a coffee-script version that

would fit the requirements in Gemfile for the application being created, Bundler could use it instead of downloading the latest version.

Maybe a new option could be included in Bundler like

–try-local-first and made available to the Rails new generator so that we could append it to ~/.railsrc, for instance.

Another take would be adding some option to the rails new generator

like “–provided-gemfile-lock” where a Gemfile.lock would be generated while packaging a Rails release and copied to the created app.

I'm not sure which would be the better option, but I would really

like you to consider some way of making creating a new Rails application as fast as it used to be before Rails 3.

Best,

Rodrigo.
4

You could accomplish something pretty similar by creating a Rails template which skips bundle install, downloads a Gemfile.lock you provide, and then run bundle install by itself.

5

I can’t find the official documentation for Rails application templates, but I guess they won’t allow you to pass any arguments to the new generator.

Maybe I would have to specify "--skip-bundle -m

path/to/my/template.rb" in my ~/.railsrc and use the template for running “bundle install --local”…