How to install bootstrap 5 with Webpacker in a Ruby on Rails 6 application on Linux

How to install bootstrap 5 with Webpacker in a Ruby on Rails 6 application on Linux

Play this article

Add bootstrap

yarn add bootstrap


calaca@calaca-PC ~/var/www/edume (bootstrap-configuration)$ yarn add bootstrap
yarn add v1.22.19
[1/4] Resolving packages...
[2/4] Fetching packages...
[3/4] Linking dependencies...
warning " > bootstrap@5.3.1" has unmet peer dependency "@popperjs/core@^2.11.8".
[4/4] Building fresh packages...
success Saved lockfile.
success Saved 1 new dependency.
info Direct dependencies
└─ bootstrap@5.3.1
info All dependencies
└─ bootstrap@5.3.1
Done in 1.63s.

The command yarn add bootstrap is used to add the Bootstrap framework to your project using Yarn, which is a package manager for JavaScript and front-end dependencies.

Bootstrap is a popular open-source front-end framework that provides a collection of pre-designed HTML, CSS, and JavaScript components and styles for building responsive and visually appealing web applications.

Check installation

yarn info boostrap version


calaca@calaca-PC ~/var/www/edume (bootstrap-configuration)$ yarn info boostrap version
yarn info v1.22.19
Done in 0.99s.

Add @popperjs/core

yarn add @popperjs/core


yarn add v1.22.19
[1/4] Resolving packages...
[2/4] Fetching packages...
[3/4] Linking dependencies...
[4/4] Building fresh packages...
success Saved lockfile.
success Saved 1 new dependency.
info Direct dependencies
└─ @popperjs/core@2.11.8
info All dependencies
└─ @popperjs/core@2.11.8
Done in 1.62s.

The command yarn add @popperjs/core is used to add the Popper.js library to your project using Yarn.

Popper.js is a JavaScript library that provides positioning and alignment for pop-up elements, tooltips, and popovers.

It's commonly used in conjunction with other libraries and frameworks like Bootstrap to manage the positioning of elements that need to appear relative to other elements on a web page.

Check installation

yarn info @popperjs/core version


calaca@calaca-PC ~/var/www/edume (bootstrap-configuration)$ yarn info @popperjs/core version
yarn info v1.22.19
Done in 0.19s.

Add the Webpacker gem package

yarn add @rails/webpacker


Check installation

npm list


Create a stylesheets directory

mkdir app/javascript/stylesheets

In Rails 6, there was a shift in how JavaScript and CSS assets are managed in the default application setup. This change was made to align with modern front-end development practices and the increasing popularity of JavaScript frameworks like React, Vue.js, and Angular.

In the context of Bootstrap 5 (or any modern CSS framework), the app/javascript directory is used for JavaScript modules and assets, while the app/assets directory is typically reserved for the asset pipeline, which is a legacy approach for managing assets in older versions of Rails.

This change was part of Rails' move toward using Webpacker, which is a tool for managing JavaScript, CSS, and other assets in Rails applications.

Create the main stylesheet file

echo > app/javascript/stylesheets/application.scss

Include CSS with Webpacker

Inside the main view file, which is app/views/layouts/application.html.erb, it's necessary to add the following line after the javascript_pack_tag.

# app/views/layouts/application.html.erb
<%= stylesheet_pack_tag 'application', 'data-turbolinks-track': 'reload' %>

The file is going to look like the following:

<!DOCTYPE html>
    <meta name="viewport" content="width=device-width,initial-scale=1">
    <%= csrf_meta_tags %>
    <%= csp_meta_tag %>

    <%= stylesheet_link_tag 'application', media: 'all', 'data-turbolinks-track': 'reload' %>
    <%= javascript_pack_tag 'application', 'data-turbolinks-track': 'reload' %>
    <%= stylesheet_pack_tag 'application', 'data-turbolinks-track': 'reload' %>

    <%= yield %>


The previous command uses the tylesheet_pack_tag, which is a Rails helper method provided by Webpacker. It's used to include a stylesheet bundle that was defined in your Webpacker configuration. This method takes the name of the pack (or bundle) as an argument.

By convention, the main stylesheet for your application is often named 'application'

In this case, we use 'application' because is the name of the stylesheet pack that we want to include, but we can have other named packs for different parts of our application.

'data-turbolinks-track': 'reload': This is an optional HTML attribute that's added to the link tag for the stylesheet. It's used in conjunction with Turbolinks, which is a JavaScript library used in Rails to speed up page transitions. The data-turbolinks-track attribute with a value of 'reload' ensures that the stylesheet is reloaded when navigating between pages using Turbolinks.

Import libraries

Inside the main javascript file, which is app/javascript/packs/application.js, add the following libraries:

# app/javascript/packs/application.js
import 'bootstrap/dist/js/bootstrap'
import 'bootstrap/dist/css/bootstrap'
import 'stylesheets/application'

The app/javascript/packs/application.jsfile would look like this:

// This file is automatically compiled by Webpack, along with any other files
// present in this directory. You're encouraged to place your actual application logic in
// a relevant structure within app/javascript and only use these pack files to reference
// that code so it'll be compiled.

import Rails from "@rails/ujs"
import Turbolinks from "turbolinks"
import * as ActiveStorage from "@rails/activestorage"
import "channels"

import 'bootstrap/dist/js/bootstrap'
import 'bootstrap/dist/css/bootstrap'
import 'stylesheets/application'



Let's test it

All the following steps are going to be performed in order to test Boostrap, webpacker and Rails 6.

Configure a sample background color

Inside the app/javascript/stylesheets/application.scss file, add the following background color:

# app/javascript/stylesheets/application.scss
body { background-color: green; }

It'll look something like the following:

Stop the server

In order to stop the Rails Server, let's press the following command:


Restart the server

rails server


Access a specific page

Possible issues

Skip these if you don't run accross any issue.

Cannot find package '@babel/plugin-proposal-private-methods'

            triggerUncaughtException(err, true /* fromPromise */);

Error: Cannot find package '@babel/plugin-proposal-private-methods' imported from /home/calaca/var/www/edume/babel-virtual-resolve-base.js



yarn add @babel/plugin-proposal-private-methods
npm install @babel/plugin-proposal-private-methods

@babel/plugin-proposal-private-property-in-object version is not meant to be imported

This @babel/plugin-proposal-private-property-in-object version is not meant to
be imported. Something is importing
@babel/plugin-proposal-private-property-in-object without declaring it in its
dependencies (or devDependencies) in the package.json file.
Add "@babel/plugin-proposal-private-property-in-object" to your devDependencies
to work around this error. This will make this message go away.
 (While processing: /home/calaca/var/www/edume/node_modules/@babel/plugin-proposal-private-property-in-object/lib/index.js)
    at Object.<anonymous> (/home/calaca/var/www/edume/node_modules/@babel/plugin-proposal-private-property-in-object/lib/index.js:28:7)
    at Module._compile (/home/calaca/var/www/edume/node_modules/v8-compile-cache/v8-compile-cache.js:192:30)
    at Object.Module._extensions..js (node:internal/modules/cjs/loader:1159:10)
    at Module.load (node:internal/modules/cjs/loader:981:32)
    at Function.Module._load (node:internal/modules/cjs/loader:822:12)
    at Module.require (node:internal/modules/cjs/loader:1005:19)
    at require (/home/calaca/var/www/edume/node_modules/v8-compile-cache/v8-compile-cache.js:159:20)
    at loadPartialConfigAsync (/home/calaca/var/www/edume/node_modules/@babel/core/lib/config/index.js:34:85)
    at Object.<anonymous> (/home/calaca/var/www/edume/node_modules/babel-loader/lib/index.js:126:26)



npm install --save-dev @babel/plugin-proposal-private-property-in-object

Test it


You've made it!

The Office GIF - The Office Happy - Discover & Share GIFs

Let's become friends

Final thoughts

I hope this article has been helpful to you. Please feel free to reach out if you have any questions. Your thoughts, suggestions, and corrections are more than welcome.

By the way, don't hesitate to drop your suggestions for new blog articles.

I look forward to seeing you next time