Category: Rails

An Odd Behaviour When Creating A Rails App

I’m currently looking into Rails 7 and found an odd behaviour when creating a new Rails app. Before creating a Rails app a few other things need to be in place, most notably Ruby, and _a_ database. My set up is this:

Ruby
3.1.0
Rails
7.0.2
rbenv
1.2.0
SQLite3
3.37.0
PostgreSQL
14.2

The simplest way to create a new Rails app is this:

rails new app_name

You can also specify various options, including, for example --css=tailwind, to use Tailwind for CSS. Since that’s what is used in a book I’m reading (‘Agile Web Development with Rails 7’ by Sam Ruby & Dave Thomas), I ran this:

rails new app_name --css=tailwind

Now I got an exception logged in the output, while also the exit code of the command was 0. Interesting. Here’s the command and the output (lots of output omitted for brevity):

rails new a_new_app --css=tailwind
      create
  …
      create  Gemfile
         run  git init from "."
Initialized empty Git repository in /Users/stephan/dev/tmp/a_new_app/.git/
      create  app
…
      create  config/master.key
      append  .gitignore
      create  config/boot.rb
…
      remove  config/initializers/new_framework_defaults_7_0.rb
         run  bundle install
Fetching gem metadata from https://rubygems.org/...........
Resolving dependencies....
Using rake 13.0.6
Using minitest 5.15.0

…
Using rails 7.0.2
Bundle complete! 16 Gemfile dependencies, 75 gems now installed.
Use `bundle info [gemname]` to see where a bundled gem is installed.
         run  bundle binstubs bundler
       rails  importmap:install
…
Add Tailwindcss include tags and container element in application layout
      insert  app/views/layouts/application.html.erb
      insert  app/views/layouts/application.html.erb
      insert  app/views/layouts/application.html.erb
…
Add default Procfile.dev
      create  Procfile.dev
Ensure foreman is installed
         run  gem install foreman from "."
Successfully installed foreman-0.87.2
/Users/stephan/.rbenv/versions/3.1.0/lib/ruby/gems/3.1.0/gems/yard-0.9.27/lib/yard/rubygems/hook.rb:88:in `require': cannot load such file -- yard (LoadError)
  from ….rbenv/…/ruby/…/yard-0.9.27/lib/yard/rubygems/hook.rb:88:in `load_yard'
  from ….rbenv/…/ruby/…/yard-0.9.27/lib/yard/rubygems/hook.rb:163:in `setup'
  from ….rbenv/…/ruby/…/yard-0.9.27/lib/yard/rubygems/hook.rb:152:in `generate'
  from ….rbenv/…/ruby/…/yard-0.9.27/lib/yard/rubygems/hook.rb:63:in `block in generation_hook'
  from ….rbenv/…/ruby/…/yard-0.9.27/lib/yard/rubygems/hook.rb:52:in `each'
  from ….rbenv/…/ruby/…/yard-0.9.27/lib/yard/rubygems/hook.rb:52:in `generation_hook'
  from ….rbenv/…/ruby/…/request_set.rb:311:in `block in install_hooks'
  from ….rbenv/…/ruby/…/request_set.rb:310:in `each'
  from ….rbenv/…/ruby/…/request_set.rb:310:in `install_hooks'
  from ….rbenv/…/ruby/…/request_set.rb:209:in `install'
  from ….rbenv/…/ruby/…/commands/install_command.rb:210:in `install_gem'
  from ….rbenv/…/ruby/…/commands/install_command.rb:226:in `block in install_gems'
  from ….rbenv/…/ruby/…/commands/install_command.rb:219:in `each'
  from ….rbenv/…/ruby/…/commands/install_command.rb:219:in `install_gems'
  from ….rbenv/…/ruby/…/commands/install_command.rb:167:in `execute'
  from ….rbenv/…/ruby/…/command.rb:323:in `invoke_with_build_args'
  from ….rbenv/…/ruby/…/command_manager.rb:180:in `process_args'
  from ….rbenv/…/ruby/…/command_manager.rb:149:in `run'
  from ….rbenv/…/ruby/…/gem_runner.rb:53:in `run'
  from ….rbenv/versions/3.1.0/bin/gem:13:in `<main>'
Add bin/dev to start foreman
      create  bin/dev
Compile initial Tailwind build
         run  rails tailwindcss:build from "."
+ /Users/stephan/.rbenv/versions/3.1.0/lib/ruby/gems/3.1.0/gems/tailwindcss-rails-2.0.5-x86_64-darwin/exe/x86_64-darwin/tailwindcss -i /Users/stephan/dev/tmp/a_new_app/app/assets/stylesheets/application.tailwind.css -o /Users/stephan/dev/tmp/a_new_app/app/assets/builds/tailwind.css -c /Users/stephan/dev/tmp/a_new_app/config/tailwind.config.js

Done in 228ms.

This is … interesting, since yard is found, when listing matching gems:

> gem list yard

*** LOCAL GEMS ***

yard (0.9.27)

However, the command that is running at this time is (apparently) executed in the context of Bundler. Since yard isn’t listed in the Gemfile, Bundler won’t find or use it:

bundle info yard
Could not find gem 'yard'.

After uninstalling yard, creating a new Rails app works fine and doesn’t log an exception.

While this solves the issue of getting the exception, it was still unclear why this happened in the first place.

Now, what is yard?

YARD is a documentation generation tool for the Ruby programming language.

https://github.com/lsegal/yard

Aha, looking into my .gemrc (which is used to configure Rubygems), I found these two lines (Yes, I like to have the documentation generated 🙂):

install: --rdoc --ri --document=yri
update: --rdoc --ri --document=yri

After removing the --document=yri, creating a new Rails app worked fine even with yard being installed.

I still don’t completely understand, why this is an issue when specifying a CSS processor, but not otherwise. This may be topic for another post.
If you have an idea about why this happens, please let me know.

A Local Rails Server in a Local Network

I’m currently working on a Rails app, that I want to have available in my local network on the default port that Ruby on Rails uses: 3000.

To do that, I added a line to the development config (config/environments/development.rb):

config.hosts << 'hostname.local'

Update: Apparently adding the line config.hosts.clear works as well. Details about this are explained in the Rails Guides.

I started using Foreman to achieve this, and installed it using:

gem install foreman

Note that, according to a Wiki Page on Github, it’s not recommended to put foreman into the Gemfile.

Then I created a Procfile that Foreman uses to start the web server (which currently is the only process I need it to start):

web: bundle exec rails s -b 0.0.0.0 -p 3000

The -b 0.0.0.0 binds the process to that IP address and -p 3000 instructs it to use port 3000.

With that set up foreman start can be used to start a Rails server in development which is available in the local network.

This way I can check the layout and functionality on a mobile phone or one of my iPads.

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