How to set up a Gemfile as a file to plugins as gem dependencies.

  • Bundler cheatsheet - see Gemfile and Install.

Samples

Sample contents for a Gemfile.

Install a gem:

gem 'foo'
gem 'foo', '~> x.y.z'
# Alternative
gem install foo -v x.y.z

Install a Jekyll plugin.

  • Single-line approach.

      gem 'foo', group: :jekyll_plugins

  • Or multi-line approach, good for multiple plugins.

      group :jekyll_plugins do
    gem 'foo'
    # Add more plugins here. Do NOT separate each line with comma.
  end

Example of Gemfile for a Jekyll project. See more info at Gemfile recipe.

Note the Jekyll and a theme are alone and any Jekyll plugins go inside a group - this ensures they load at the correct order at build time.

source 'https://rubygems.org'

gem 'jekyll', '~> 3.9'

gem 'minima'

group :jekyll_plugins do
  gem 'jekyll-feed'
  gem 'jekyll-sitemap'
end

Notes on the above:

  • The source line is needed to prevent an error.
  • Jekyll restriction will prevent getting Jekyll 4.0.0.
  • The group helps plugins to be loaded at the correct point when building the site.

See also Recommended Jekyll plugins page.

Resources

  • Bundler
  • Jekyll Plugin Installation doc.
  • Plugins
    • GitHub Pages Plugin
      • github/pages-gem repo
      • GitHub Pages plugin in the Jekyll docs. This gives you a couple of Jekyll plugins and themes, which may be unnecessary if you are running locally and only need to install one or two of those.
      • Versions - Plugins supported by the github-pages plugin.
    • GitHub Metadata
  • See a fuller Gemfile with comments in one of my repos here.

Why the jekyll_plugins group in the samples above? The docs say:

Jekyll gives this particular group of gems in your Gemfile a different treatment. Any gem included in this group is loaded before Jekyll starts processing the rest of your source directory.

A gem included here will be activated even if its not explicitly listed under the plugins: key in your site’s config file.