Jekyll PostCSS

A plugin to use PostCSS plugins like Autoprefixer or Tailwind CSS with Jekyll.

The goal of this project is to be able to use modern CSS tooling with Jekyll, without the hassle of dealing with other build tools. It should be as easy as bundle exec jekyll serve.

Installation

Add this line to your application's Gemfile:

gem 'jekyll-postcss'

And then add this line to your application's _config.yml:

# _config.yml

plugins:
  - jekyll-postcss

Usage

Make sure you have postcss installed.

Add your PostCSS plugins to a postcss.config.js file in the root of your repository.

// postcss.config.js

module.exports = {
  plugins: [
    require("autoprefixer"), // example of plugin you might use
    ...(process.env.JEKYLL_ENV == "production" // example of only using a plugin in production
      ? [require("cssnano")({ preset: "default" })]
      : [])
  ]
};

All CSS and SCSS/Sass files will now be processed by PostCSS.

SCSS/Sass

If using SCSS/Sass, you must have postcss-scss installed and configured in your postcss.config.js

module.exports = {
  parser: 'postcss-scss',
  plugins: [
    // ...
  ]
};

Caching

Caching is enabled by default so PostCSS will only be called when the CSS content has changed. If needed you can disable caching in your Jekyll configuration to force the CSS to be recompiled every time.

If you are using the TailwindCSS JIT, you most likely need to disable the caching feature.

# _config.yml

postcss:
  cache: false

Deployment

When deploying, make sure to set your JEKYLL_ENV to something like production or staging. This is necessary to make sure that jekyll-postcss will not use internal development conveniences when building on your host's servers.

This can be done so by setting your build command like so

JEKYLL_ENV=production bundle exec jekyll build

or using your hosts proprietary configuration. Here is an example using Netlify.

# netlify.toml

[context.production.environment]
  JEKYLL_ENV = "production"

[context.branch-deploy.environment]
  JEKYLL_ENV = "staging"

[context.deploy-preview.environment]
  JEKYLL_ENV = "staging"

Front Matter Reminder

Your stylesheets still need to have front matter for them to be processed by Jekyll.

---
---

/* Example using Tailwind */
@tailwind base;
@tailwind components;
@tailwind utilities;

Alternatives

• postcss-jekyll-v2: works well with TailwindCSS 2.0
• bridgetown - A Jekyll fork, which uses Webpack for modern JS and CSS and is actively maintained.

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/mhanberg/jekyll-postcss. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

License

The gem is available as open source under the terms of the MIT License.

Code of Conduct

Everyone interacting in the Jekyll PostCSS project’s codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.