Rails 5.1.7: Sprockets::Rails::Helper::AssetNotFound

Question

we have a rails 5.1.7 application and all is working fine in the dev environment. but in staging environment or when running server using rails s -e staging, we see this error "Sprockets::Rails::Helper::AssetNotFound".

example, The asset "fontawesome-free-5.1.1-web/css/all.min.css" is not present in the asset pipeline

the folder fontawesome-free-5.1.1-web is located under public/styleheets.

I have tried moving the folder to vendor/stylesheets or assets/stylesheets but I see the same error.

below is my environments/staging.rb

AppName::Application.configure do
  config.cache_classes = true

  config.consider_all_requests_local       = true
  config.action_controller.perform_caching = true
  config.action_view.cache_template_loading = true
  config.action_dispatch.x_sendfile_header = 'X-Accel-Redirect'

  config.log_level = :debug
  memcached_config = YAML.load_file(Rails.root.join('config/memcached.yml'))
  memcached_hosts = memcached_config['defaults']['servers']
  config.cache_store = :mem_cache_store, *memcached_hosts


  config.action_mailer.delivery_method = :smtp
  config.action_mailer.perform_deliveries = true
  config.action_mailer.raise_delivery_errors = true
  config.i18n.fallbacks = true

  config.active_support.deprecation = :notify

  config.eager_load = true
  config.assets.js_compressor = Uglifier.new(harmony: true)
  config.assets.compile = false
  config.assets.raise_runtime_errors = true
  config.assets.debug = true
end

Any help on what could be going wrong here would be really great, Thanks.

Answer 1

I'm assuming you're doing this:

<%= stylesheet_link_tag 'fontawesome/all.min.css' %>  

vendor/
└── assets/                  # <= this one is important
    └── stylesheets/
        └── fontawesome/
            └── all.min.css

Directories in vendor/assets and app/assets are automatically added to assets paths. These are the paths sprockets is using to find assets:

>> puts Rails.application.config.assets.paths
...
/myapp/app/assets/stylesheets
/myapp/vendor/assets/stylesheets         # <=
/usr/local/bundle/gems/coffee-rails-4.2.2/lib/assets/javascripts
/usr/local/bundle/gems/actioncable-5.2.8.1/lib/assets/compiled
...

You have config.assets.compile = false, that means sprockets is done looking around in assets paths and compiling on the fly. It's now expecting precompiled assets in public/assets:

# assuming sprockets is still serving files (but not compiling them anymore)
>> Rails.application.config.public_file_server.enabled
=> true
>> Rails.application.config.assets.compile
=> false

>> helper.asset_path("fontawesome/all.min.css")
Traceback (most recent call last):
        1: from (irb):5
Sprockets::Rails::Helper::AssetNotFound (The asset "fontawesome/all.min.css" is not present in the asset pipeline.)

You have to bin/rails assets:precompile:

# config/initializers/assets.rb

# but make it precompilable first
Rails.application.config.assets.precompile += ["fontawesome/all.min.css"]

$ bin/rails assets:precompile

I, [2023-09-10T10:04:24.038220 #1]  INFO -- : Writing /myapp/public/assets/fontawesome/all.min-1f62e82d4d0217052a8d48596d631f5c58ee5149386c719419046118e4fa43f3.css
...

Should work now:

>> helper.asset_path("fontawesome/all.min.css")
=> "/assets/fontawesome/all.min-1f62e82d4d0217052a8d48596d631f5c58ee5149386c719419046118e4fa43f3.css"

# check if it is being served
>> require "open-uri"
>> URI.open(helper.asset_path("fontawesome/all.min.css", host: "http://localhost:3000")).read
=> "i am font\n"

https://guides.rubyonrails.org/v5.0/configuring.html#configuring-assets

---

Update

To handle files in bulk, there are two options. Add a proc that would dynamically match assets for precompilation:

# config/initializers/assets.rb

VENDOR_ASSETS = lambda do |logical_path, filename|
  filename.start_with?(::Rails.root.join("vendor/assets/").to_s) &&
    [".css", ".js"].include?(File.extname(logical_path))
end

Rails.application.config.assets.precompile += [VENDOR_ASSETS]

https://github.com/rails/sprockets-rails/blob/v3.4.2/lib/sprockets/railtie.rb#L88

A better option is to use manifest.js, which is the default in later rails versions:

# config/initializers/assets.rb

# don't need this in sprockets v4
Rails.application.config.assets.precompile += ["manifest.js"]

// app/assets/config/manifest.js

//= link_tree ../images
//= link_directory ../javascripts .js
//= link_directory ../stylesheets .css
//
// link everything to be precompiled
//= link_tree ../../../vendor/assets/stylesheets .css
//= link_tree ../../../vendor/assets/javascripts .js
//
// or one file at a time 
//= link fontawesome/all.min.css

https://github.com/rails/sprockets#directives

---

Also, when you precompile assets, that means you want load them directly through a url. If you just use //= require directives, then required files don't need to be precompiled as they are merged into the file that gets precompiled. You just get one big application.css file:

/* app/assets/stylesheets/application.css */

/*
 *= require_tree .
 *= require_self
 *= require fontawesome/all.min
 */

If you're precompiling locally to test things out, don't forget to bin/rails assets:clobber after you're done, you don't want precompiled assets in development.