netlify-cms-oauth-firebase

This is a Firebase Cloud Function that allows Netlify CMS to authenticate with GitHub or GitLab via OAuth2.

Setup

0) Prerequisites

These instructions assume that you have already created a Firebase project and have installed and configured the Firebase CLI Tools. See the Firebase CLI Reference for more details.

Note: The Firebase project must be configured to use the Blaze plan, as the function needs to be able to make outbound network requests to non-Google services. Additionally, the function uses the Node.js 10 runtime, which is not available on the free plan.

1) Get the code

Clone the repository and install dependencies:

git clone https://github.com/Herohtar/netlify-cms-oauth-firebase
cd netlify-cms-oauth-firebase/functions
npm i
cd ..

2) Create an OAuth app

You will need an OAuth app to authenticate with. For GitHub, the instructions can be found in the GitHub Developer Documentation.

For now, the values that you provide for the fields do not matter. The authorization callback URL will need to be configured once you have the Firebase Function URL in order for the service to work.

3) Configure the Firebase environment

Tell Firebase which project to use:

firebase use your-project-id

Set the oauth.client_id and oauth.client_secret Firebase environment variables using the values from the GitHub OAuth app:

firebase functions:config:set oauth.client_id=yourclientid oauth.client_secret=yourclientsecret

For GitHub Enterprise and GitLab you will need to set the oauth.git_hostname environment variable.

For GitLab you will also need to set the following additional environment variables as specified:

oauth.provider=gitlab
oauth.scopes=api
oauth.authorize_path=/oauth/authorize
oauth.token_path=/oauth/token

For security reasons set an origin_pattern to match the origins, so that only trusted origins could be use to authenticate. Replace yoursite.com with your domain.

firebase functions:config:set oauth.origin_pattern="(^https://yoursite.com$|^https://www.yoursite.com$|^http://localhost:3000$)"

4) Deploy the function

Deploy the function to Firebase:

firebase deploy --only functions

At this point you should update the authorization callback URL in your GitHub OAuth app's settings to point to the URL of your Firebase function, which should be of the form: https://us-central1-your-project-id.cloudfunctions.net/oauth/callback

5) Configure Netlify CMS

Finally, update your Netlify CMS config.yml to point to the function:

backend:
  name: github # Or gitlab
  repo: username/repo # Your username and repository
  branch: master # Branch to use
  base_url: https://us-central1-your-project-id.cloudfunctions.net # The base URL for your Firebase Function
  auth_endpoint: /oauth/auth # The path to the OAuth endpoint of the function