--- title: GitHub Actions --- When building a Jekyll site with GitHub Pages, the standard flow is restricted for security reasons and to make it simpler to get a site setup. For more control over the build and still host the site with GitHub Pages you can use GitHub Actions. ## Advantages of using Actions ### Control over gemset - **Jekyll version** --- Instead of using the currently enabled version at `3.9.0`, you can use any version of Jekyll you want. For example `{{site.version}}`, or point directly to the repository. - **Plugins** --- You can use any Jekyll plugins irrespective of them being on the [supported versions][ghp-whitelist] list, even `*.rb` files placed in the `_plugins` directory of your site. - **Themes** --- While using a custom theme is possible without Actions, it is now simpler. ### Workflow Management - **Customization** --- By creating a workflow file to run Actions, you can specify custom build steps, use environment variables. - **Logging** --- The build log is visible and can be tweaked to be verbose, so it is much easier to debug errors using Actions. ## Workspace setup The first and foremost requirement is a Jekyll project hosted at GitHub. Choose an existing Jekyll project or follow the [quickstart]({{ '/docs/' | relative_url }}) and push the repository to GitHub if it is not hosted there already. We're only going to cover builds from the `main` branch in this page. Therefore, ensure that you are working on the `main` branch. If necessary, you may create it based on your default branch. When the Action builds your site, the contents of the _destination_ directory will be automatically pushed to the `gh-pages` branch with a commit, ready to be used for serving. {: .note .warning} The Action we're using here will create (or reset an existing) `gh-pages` branch on every successful deploy.
So, if you have an existing `gh-pages` branch that is used to deploy your production build, ensure to make a backup of the contents into a different branch so that you can rollback easily if necessary. The Jekyll site we'll be using for the rest of this page initially consists of just a `_config.yml`, an `index.md` page and a `Gemfile`. The contents are respectively: ```yaml # _config.yml title: "Jekyll Actions Demo" ``` {% raw %} ```liquid --- --- Welcome to My Home Page {% assign date = '2020-04-13T10:20:00Z' %} - Original date - {{ date }} - With timeago filter - {{ date | timeago }} ``` {% endraw %} ```ruby # Gemfile source 'https://rubygems.org' gem 'jekyll', '~> 4.2' group :jekyll_plugins do gem 'jekyll-timeago', '~> 0.13.1' end ``` {: .note .info} The demo site uses Jekyll 4 and a [third-party plugin][timeago-plugin], both of which are currently not whitelisted for use on GitHub pages. The plugin will allow us to describe how far back a date was from today. e.g. If we give a date as `2016-03-23T10:20:00Z` and the current date is `2020-04-13T10:20:00Z`, then the output would be `4 years and 3 weeks ago`. {: .note .info} The action we're using takes care of installing the Ruby gems and dependencies. While that keeps the setup simple for the user, one may encounter issues if they also check-in `Gemfile.lock` if it was generated with an old version of Bundler. ### Setting up the Action GitHub Actions are registered for a repository by using a YAML file inside the directory path `.github/workflows` (note the dot at the start). Here we shall employ [Jekyll Actions][jekyll-actions] from the Marketplace for its simplicity. Create a **workflow file**, say `github-pages.yml`, using either the GitHub interface or by pushing a YAML file to the workflow directory path manually. The base contents are: {% raw %} ```yaml name: Build and deploy Jekyll site to GitHub Pages on: push: branches: - main jobs: github-pages: runs-on: ubuntu-latest steps: - uses: actions/checkout@v2 - uses: helaili/jekyll-action@v2 with: token: ${{ secrets.GITHUB_TOKEN }} ``` {% endraw %} The above workflow can be explained as the following: - We trigger the build using **on.push** condition for `main` branch only --- this prevents the Action from overwriting the `gh-pages` branch on any feature branch pushes. - The **name** of the job matches our YAML filename: `github-pages`. - The **checkout** action takes care of cloning your repository. - We specify our selected **action** and **version number** using `helaili/jekyll-action@2.0.5`. This handles the build and deploy. - We set a reference to a secret **environment variable** for the action to use. The `GITHUB_TOKEN` is a _Personal Access Token_ and is detailed in the next section. Instead of using the **on.push** condition, you could trigger your build on a **schedule** by using the [on.schedule] parameter. For example, here we build daily at midnight by specifying **cron** syntax, which can be tested at the [crontab guru] site. ```yaml on: schedule: - cron: "0 0 * * *" ``` Note that this string must be quoted to prevent the asterisks from being evaluated incorrectly. [on.schedule]: https://help.github.com/en/actions/reference/workflow-syntax-for-github-actions#onschedule [crontab guru]: https://crontab.guru/ ### Providing permissions The action needs permissions to push to your `gh-pages` branch. So you need to create a GitHub **authentication token** on your GitHub profile, then set it as an environment variable in your build using _Secrets_: 1. On your GitHub profile, under **Developer Settings**, go to the [Personal Access Tokens][tokens] section. 2. **Create** a token. Give it a name like "GitHub Actions" and ensure it has permissions to `public_repos` (or the entire `repo` scope for private repository) --- necessary for the action to commit to the `gh-pages` branch. 3. **Copy** the token value. 4. Go to your repository's **Settings** and then the **Secrets** tab. 5. **Create** a token named `GITHUB_TOKEN` (_important_). Give it a value using the value copied above. ### Build and deploy On pushing any local changes onto `master`, the action will be triggered and the build will **start**. To watch the progress and see any build errors, check on the build **status** using one of the following approaches: - **View by commit** - Go to the repository level view in GitHub. Under the most recent commit (near the top) you’ll see a **status symbol** next to the commit message as a tick or _X_. Hover over it and click the **details** link. - **Actions tab** - Go to the repository's Actions tab. Click on the `jekyll` workflow tab. If all goes well, all steps will be green and the built assets will now exist on the `gh-pages` branch. On a successful build, GitHub Pages will **publish** the site stored on the repository `gh-pages` branches. Note that you do not need to setup a `gh-pages` branch or enable GitHub Pages, as the action will take care of this for you. (For private repositories, you'll have to upgrade to a paid plan). To see the **live site**: 1. Go to the **environment** tab on your repository. 2. Click **View Deployment** to see the deployed site URL. 3. View your site at the **URL**. Make sure the `timeago` filter works as expected. 4. Optionally **add** this URL to your repository's main page and to your `README.md`, to make it easy for people to find. When you need to make further **changes** to the site, commit to `master` and push. The workflow will build and deploy your site again. Be sure **not to edit** the `gh-pages` branch directly, as any changes will be lost on the next successful deploy from the Action. ## External links - [jekyll-actions] is an action available on the GitHub Marketplace and was used in this guide. - [jekyll-actions-quickstart] is an unofficial repository that includes a live demo of the `jekyll-actions` action. That project can be used as a template for making a new site. - [jekyll-action-ts] is another action to build and publish Jekyll sites on GiHub Pages that includes HTML formatting options with Prettier and caching. [ghp-whitelist]: https://pages.github.com/versions/ [timeago-plugin]: https://rubygems.org/gems/jekyll-timeago [tokens]: https://github.com/settings/tokens [jekyll-actions]: https://github.com/marketplace/actions/jekyll-actions [jekyll-actions-quickstart]: https://github.com/MichaelCurrin/jekyll-actions-quickstart [jekyll-action-ts]: https://github.com/limjh16/jekyll-action-ts