jekyll-action

A GitHub Action to build and publish Jekyll sites to GitHub Pages

Out-of-the-box Jekyll with GitHub Pages allows you to leverage a limited, white-listed, set of gems. Complex sites requiring custom ones or non white-listed ones (AsciiDoc for intstance) used to require a continuous integration build in order to pre-process the site.

Remember that GitHub is serving your built static site, not it's sources. So when configuring GitHub Pages in your project settings, use gh-pages branch as a Source for GitHub Pages. If you are setting up username.github.io repository, you'll have to use master branch, so sources can be located in another orphaned branch in the repo (which you can safely mark as default after the first publication). In addition to that default behaviour, you can configure the branch this plugin pushes into with the target_branch-option. Keep in mind to set the source branch accordingly at the GitHub Pages Settings page.

Note that this is a rather simple (naive maybe) Docker based action. @limjh16 has created a JS based version of this action which saves the container download time and might help with non default use cases (such as but not limited to: specific package or library that is not available as a Gem).

Usage

Create a Jekyll site

If you repo doesn't already have one, create a new Jekyll site: jekyll new sample-site. See the Jekyll website for more information. In this repo, we have created a site within a sample_site folder within the repository because the repository's main goal is not to be a website. If it was the case, we would have created the site at the root of the repository.

Create a Gemfile

As you are using this action to leverage specific Gems, well, you need to declare them! In the sample below we are using the Jekyll AsciiDoc plugin

source 'https://rubygems.org'

gem 'jekyll', '~> 3.8.5'
gem 'coderay', '~> 1.1.0'

group :jekyll_plugins do
  gem 'jekyll-asciidoc', '~> 2.1.1'
end

Configure your Jekyll site

Edit the configuration file of your Jekyll site (_config.yml) to leverage these plugins. In our sample, we want to leverage AsciiDoc so we added the following section:

asciidoc: {}
asciidoctor:
  base_dir: :docdir
  safe: unsafe
  attributes:
    - idseparator=_
    - source-highlighter=coderay
    - icons=font

Note that we also renamed index.html to index.adoc and modified this file accordingly in order to leverage AsciiDoc.

Use the action

Use the helaili/jekyll-action@master action in your workflow file. It needs access to the out-of-the-box GITHUB_TOKEN secret. The directory where the Jekyll site lives will be detected (based on the location of _config.yml) but you can also explicitly set this directory by setting the jekyll_src parameter (sample_site for us). The SRC environment variable is also supported for backward compatibilty but it is deprecated. The action will search for Gemfile location. If your want to specify it explicitly (e.g. if you have multiple Gemfiles per project), you should update gem_src input parameter accordingly.

Use the actions/cache action in the workflow as well, to shorten build times and decrease load on GitHub's servers

name: Testing the GitHub Pages publication

on:
  push

jobs:
  jekyll:
    runs-on: ubuntu-16.04
    steps:
    - uses: actions/checkout@v2

    # Use GitHub Actions' cache to shorten build times and decrease load on servers
    - uses: actions/cache@v2
      with:
        path: vendor/bundle
        key: ${{ runner.os }}-gems-${{ hashFiles('**/Gemfile') }}
        restore-keys: |
          ${{ runner.os }}-gems-

    # Standard usage
    - uses:  helaili/jekyll-action@v2
      with:
        token: ${{ secrets.GITHUB_TOKEN }}

    # Specify the Jekyll source location as a parameter
    - uses: helaili/jekyll-action@v2
      with:
        token: ${{ secrets.GITHUB_TOKEN }}
        jekyll_src: 'sample_site'

    # Specify the target branch (optional)
    - uses: helaili/jekyll-action@v2
      with:
        token: ${{ secrets.GITHUB_TOKEN }}
        target_branch: 'gh-pages'

Upon successful execution, the GitHub Pages publishing will happen automatically and will be listed on the environment tab of your repository.

Just click on the View deployment button of the github-pages environment to navigate to your GitHub Pages site.

Inputs

token

The GITHUB_TOKEN secret. This is mandatory unless build_only is set to true.

jekyll_env

The Jekyll environment to build (default to production)

jekyll_src

The Jekyll website source directory

jekyll_build_options

Additional Jekyll build arguments (see the Jekyll doc)

gem_src

The Jekyll Gemfile directory

target_branch

The target branch name the sources get pushed to

build_only

When set to true, the Jekyll site will be built but not published

pre_build_commands

Commands to run prior to build and deploy. Useful for ensuring build dependencies are up to date or installing new dependencies. For example, use apk --update add imagemagick to install ImageMagick.

Deprecation

This action previously used a JEKYLL_PAT environment variable instead of the token parameter. This is now depreacted.

I have a problem

Create a ACTIONS_STEP_DEBUG secret with value true and run the workflow again.

Note on custom domains

If you're using a Custom Domain for your GitHub Pages site, you will need to ensure that the CNAME file exists in the repository root of the main (or master) branch so that it can be copied to the deployment root when your site is deployed.

If your GitHub Pages site is run off the main (or master) branch, you can modify the Custom Domain setting in the Repository Settings to automatically generate and commit the CNAME file.

If your GitHub Pages site is run off an alternate branch, however, you will need to manually create and commit the CNAME file with your custom domain as its contents, otherwise the file will be committed to the deployment branch and overwritten the next time the action is run.