--- layout: docs title: Continuous Integration permalink: /docs/continuous-integration/ --- You can easily test your website build against one or more versions of Ruby. The following guide will show you how to set up a free build environment on [Travis][0], with [GitHub][1] integration for pull requests. Paid alternatives exist for private repositories. [0]: https://travis-ci.org/ [1]: https://github.com/ ## 1. Enabling Travis and GitHub Enabling Travis builds for your GitHub repository is pretty simple: 1. Go to your profile on travis-ci.org: https://travis-ci.org/profile/username 2. Find the repository for which you're interested in enabling builds. 3. Click the slider on the right so it says "ON" and is a dark grey. 4. Optionally configure the build by clicking on the gear icon. Further configuration happens in your `.travis.yml` file. More details on that below. ## 2. The Test Script The simplest test script simply runs `jekyll build` and ensures that Jekyll doesn't fail to build the site. It doesn't check the resulting site, but it does ensure things are built properly. When testing Jekyll output, there is no better tool than [html-proofer][2]. This tool checks your resulting site to ensure all links and images exist. Utilize it either with the convenient `htmlproofer` command-line executable, or write a Ruby script which utilizes the gem. Save the commands you want to run and succeed in a file: `./script/cibuild` ### The HTML Proofer Executable ```sh #!/usr/bin/env bash set -e # halt script on error bundle exec jekyll build bundle exec htmlproofer ./_site ``` Some options can be specified via command-line switches. Check out the `html-proofer` README for more information about these switches, or run `htmlproofer --help` locally. For example to avoid testing external sites, use this command: ```sh $ bundle exec htmlproofer ./_site --disable-external ``` ### The HTML Proofer Library You can also invoke `html-proofer` in Ruby scripts (e.g. in a Rakefile): ```ruby #!/usr/bin/env ruby require 'html-proofer' HTMLProofer.check_directory("./_site").run ``` Options are given as a second argument to `.new`, and are encoded in a symbol-keyed Ruby Hash. For more information about the configuration options, check out `html-proofer`'s README file. [2]: https://github.com/gjtorikian/html-proofer ## 3. Configuring Your Travis Builds This file is used to configure your Travis builds. Because Jekyll is built with Ruby and requires RubyGems to install, we use the Ruby language build environment. Below is a sample `.travis.yml` file, followed by an explanation of each line. **Note:** You will need a Gemfile as well, [Travis will automatically install](https://docs.travis-ci.com/user/languages/ruby/#Dependency-Management) the dependencies based on the referenced gems: ```ruby source "https://rubygems.org" gem "jekyll" gem "html-proofer" ``` Your `.travis.yml` file should look like this: ```yaml language: ruby rvm: - 2.2.5 before_script: - chmod +x ./script/cibuild # or do this locally and commit # Assume bundler is being used, therefore # the `install` step will run `bundle install` by default. script: ./script/cibuild # branch whitelist, only for GitHub Pages branches: only: - gh-pages # test the gh-pages branch - /pages-(.*)/ # test every branch which starts with "pages-" env: global: - NOKOGIRI_USE_SYSTEM_LIBRARIES=true # speeds up installation of html-proofer sudo: false # route your build to the container-based infrastructure for a faster build ``` Ok, now for an explanation of each line: ```yaml language: ruby ``` This line tells Travis to use a Ruby build container. It gives your script access to Bundler, RubyGems, and a Ruby runtime. ```yaml rvm: - 2.2.5 ``` RVM is a popular Ruby Version Manager (like rbenv, chruby, etc). This directive tells Travis the Ruby version to use when running your test script. ```yaml before_script: - chmod +x ./script/cibuild ``` The build script file needs to have the *executable* attribute set or Travis will fail with a permission denied error. You can also run this locally and commit the permissions directly, thus rendering this step irrelevant. ```yaml script: ./script/cibuild ``` Travis allows you to run any arbitrary shell script to test your site. One convention is to put all scripts for your project in the `script` directory, and to call your test script `cibuild`. This line is completely customizable. If your script won't change much, you can write your test incantation here directly: ```yaml install: gem install jekyll html-proofer script: jekyll build && htmlproofer ./_site ``` The `script` directive can be absolutely any valid shell command. ```yaml # branch whitelist, only for GitHub Pages branches: only: - gh-pages # test the gh-pages branch - /pages-(.*)/ # test every branch which starts with "pages-" ``` You want to ensure the Travis builds for your site are being run only on the branch or branches which contain your site. One means of ensuring this isolation is including a branch whitelist in your Travis configuration file. By specifying the `gh-pages` branch, you will ensure the associated test script (discussed above) is only executed on site branches. If you use a pull request flow for proposing changes, you may wish to enforce a convention for your builds such that all branches containing edits are prefixed, exemplified above with the `/pages-(.*)/` regular expression. The `branches` directive is completely optional. Travis will build from every push to any branch of your repo if leave it out. ```yaml env: global: - NOKOGIRI_USE_SYSTEM_LIBRARIES=true # speeds up installation of html-proofer ``` Using `html-proofer`? You'll want this environment variable. Nokogiri, used to parse HTML files in your compiled site, comes bundled with libraries which it must compile each time it is installed. Luckily, you can dramatically decrease the install time of Nokogiri by setting the environment variable `NOKOGIRI_USE_SYSTEM_LIBRARIES` to `true`.
Be sure to exclude vendor from your _config.yml

Travis bundles all gems in the vendor directory on its build servers, which Jekyll will mistakenly read and explode on.

```yaml exclude: [vendor] ``` By default you should supply the `sudo: false` command to Travis. This command explicitly tells Travis to run your build on Travis's [container-based infrastructure](https://docs.travis-ci.com/user/workers/container-based-infrastructure/#Routing-your-build-to-container-based-infrastructure). Running on the container-based infrastructure can often times speed up your build. If you have any trouble with your build, or if your build does need `sudo` access, modify the line to `sudo: required`. ```yaml sudo: false ``` ### Troubleshooting **Travis error:** *"You are trying to install in deployment mode after changing your Gemfile. Run bundle install elsewhere and add the updated Gemfile.lock to version control."* **Workaround:** Either run `bundle install` locally and commit your changes to `Gemfile.lock`, or remove the `Gemfile.lock` file from your repository and add an entry in the `.gitignore` file to avoid it from being checked in again. ### Questions? This entire guide is open-source. Go ahead and [edit it][3] if you have a fix or [ask for help][4] if you run into trouble and need some help. [3]: https://github.com/jekyll/jekyll/edit/master/site/_docs/continuous-integration.md [4]: https://jekyllrb.com/help/