How Gatsby Works with GitHub Pages

GitHub pages is a service offered by GitHub that allows hosting for websites configured straight from the repository. A Gatsby site can be hosted on GitHub pages with just a few configurations to the codebase and the repository’s settings.

You can publish your site on GitHub pages several different ways:

• to a path like username.github.io/reponame/ or /docs
• to a subdomain based on your username or organization name: username.github.io or orgname.github.io
• to the root subdomain at username.github.io, and then configured to use a custom domain

Configuring the GitHub Pages source branch

You must select which branch will be deployed from your repository settings in GitHub for GitHub pages to function. On GitHub:

1. Navigate to your site’s repository.

2. Under the repository name, click Settings.

3. In the GitHub Pages section, use the Source drop-down to select master (for publishing to the root subdomain) or gh-pages (for publishing to a path like /docs) as your GitHub Pages publishing source.

4. Click Save.

Installing the gh-pages package

The easiest way to push a Gatsby app to GitHub Pages is by using a package called gh-pages.

Using a deploy script

A custom script in your package.json makes it easier to build your site and move the contents of the built files to the proper branch for GitHub pages, this helps automate that process.

Deploying to a path on GitHub pages

For sites deployed at a path like username.github.io/reponame/, the --prefix-paths flag is used because your website will end up inside a folder like username.github.io/reponame/. You’ll need to add your /reponame path prefix as an option to gatsby-config.js:

Then add a deploy script to package.json in your repository’s codebase:

When you run npm run deploy all contents of the public folder will be moved to your repository’s gh-pages branch. Make sure that your repository’s settings has the gh-pages branch set as the source to deploy from.

Note: to select master or gh-pages as your publishing source, you must have the branch present in your repository. If you don’t have a master or gh-pages branch, you can create them and then return to source settings to change your publishing source.

Deploying to a GitHub pages subdomain at github.io

For a repository named like username.github.io, you don’t need to specify pathPrefix and your website needs to be pushed to the master branch.

After running npm run deploy you should see your website at username.github.io

Deploying to the root subdomain and using a custom domain

If you use a custom domain, don’t add a pathPrefix as it will break navigation on your site. Path prefixing is only necessary when the site is not at the root of the domain like with repository sites.

Note: Don’t forget to add your CNAME file to the static directory.

Deploying to GitHub pages from a CI server

It’s also possible to deploy your website to gh-pages through a CI server. This example uses Travis CI, a hosted Continuous Integration service, but other CI systems could work as well.

You can use the gh-pages npm module to deploy. But first, you need to configure it with proper credentials so that gh-pages is able to push a new branch.

Obtain a GitHub token for authenticating with CI

To push changes from the CI system to GitHub, you’ll need to authenticate. It’s recommended to use GitHub developer tokens.

In GitHub go to your account settings -> Developer settings -> Personal access tokens, and create a new token that provides the repo access permissions.

In Travis’s settings for the repository, add a new secret environment variable of the name GH_TOKEN with the value of the token copied from GitHub. Make sure you DO NOT toggle the “display in build logs” setting to on as the token should remain secret. Otherwise, strangers would be able to push to your repository (a big security issue).

Add script to deploy to GitHub Pages via CI

Update the Gatsby project’s package.json to also include a deploy run script which invokes gh-pages with two important command-line arguments:

1. -d public - specifies the directory in which the built files exist and will be pushed as a source to GitHub pages
2. -r URL - the GitHub repository URL, including the use of the secret GitHub token (as a secret environment variable) to be able to push changes to the gh-pages branch, in the form of https://$GH_TOKEN@github.com/<github username>/<github repository name>.git

Here’s an example (be sure to update the user and repo names to your own):

Update .travis.yml configuration

The following .travis.yml configuration provides a reference:

To break-down the important bits here for deploying the Gatsby website from Travis to GitHub pages:

1. before_script is used to install the Gatsby CLI so it can be used in the project’s run script to build the Gatsby website
2. deploy will only fire when the build runs on the master branch, in which case it will fire off the deploy script. In the above example, the Gatsby site is located in a docs/ directory. The script changes into that directory, installs all the website dependencies, and runs the deploy script as was set in the previous step.

Committing and pushing both the .travis.yml and package.json files to your base branch will be the final step in the process.