Firebase Hosting: Preview and Deploy via GitHub Actions

You start building an Angular or a Scully application and at some point you want to invite colleagues, friends, family or customers to check it out. Firebase Hosting allows to host your static or dynamic web apps for FREE 💸. You are setting up a GitHub workflow deploying your Scully app (works with Angular and any other web framework) to preview and live channel.

Demo source code and hosted on Firebase 🔥.

Before you dive straight into this you will need a

• Firebase Account
• GitHub Account and a private or public repo for your web app

Use your existing web application or create a new one by following Angular 10 with Tailwind CSS or Jamstack: Angular + Scully + Tailwind CSS to get started.

Getting started

Install Firebase CLI minimum in v8.12.0 for preview channels support.

# install firebase cli
npm install -g firebase-tools

# init firebase hosting
firebase init hosting
# hosting already setup, prepare GitHub workflow
firebase init hosting:github

Follow the CLI prompts to setup Firebase hosting and GitHub workflow.

Firebase Hosting Setup

Start by selecting an existing Firebase project, create one in Firebase console, or create a new project through the CLI.

Next enter the public directory containing all files of your web app including index.html which is uploaded to Firebase hosting

# Angular
dist/<project-name>

# Scully `outDir` specified in your scully.<project-name>.ts defaults to
dist/static

You can change the public directory anytime in firebase.json file.

Answer the next question "Configure as a single-page app (rewrite all urls to /index.html)?" with yes for Angular apps (and other single-page apps) and no for Scully apps (and other static-site apps).

Let Firebase CLI initialize your GitHub repository for automatic deploys. Several steps are taken care by the Firebase CLI for you

• Creating a Firebase service account with deployment permissions to Firebase Hosting
• Encrypt and add secret to GitHub repository
• Creating GitHub workflow yaml files

Enter no for the next two questions to overwrite dist/static/404.html and dist/static/index.html, let those be generated by Scully.

Select a GitHub repository to setup your secret token for your workflow and enter a build script to build Angular and Scully like npm ci && npm run build:ci. For a Scully build add the following two scripts to your package.json:

"build:ci": "npm run build:prod && npm run scully:ci"
"scully:ci": "scully -- --host='0.0.0.0' --scanRoutes --serverTimeout=60000",

If you like to deploy to live channel on merged Pull Request answer with yes and enter your branch name for the live channel for example main.

GitHub Workflow

You should have now two workflows if you used the Firebase CLI. The workflows use the GitHub Action Deploy to Firebase Hosting, currently in alpha release.

Workflow to deploy to a preview channel on Pull Request .github/workflows/firebase-hosting-pull-request.yml

# This file was auto-generated by the Firebase CLI
# https://github.com/firebase/firebase-tools

name: Deploy to Firebase Hosting on PR
'on': pull_request
jobs:
  build_and_preview:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
      - run: 'npm ci && npm run build:ci'
      # Add additional build steps here
      # - run: ...
      - uses: FirebaseExtended/action-hosting-deploy@v0
        with:
          repoToken: '${{ secrets.GITHUB_TOKEN }}'
          firebaseServiceAccount: '${{ secrets.FIREBASE_SERVICE_ACCOUNT }}'
          projectId: your-firebase-project-id
          # default expire value 7 days
          # expires: 7d
        env:
          FIREBASE_CLI_PREVIEWS: hostingchannels

Workflow to deploy to your live channel on push to main branch .github/workflows/firebase-hosting-merge.yml

# This file was auto-generated by the Firebase CLI
# https://github.com/firebase/firebase-tools

name: Deploy to Firebase Hosting on merge
'on':
  push:
    branches:
      - main
jobs:
  build_and_deploy:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
      - run: 'npm ci && npm run build:ci'
      # Add additional build steps here
      # - run: ...
      - uses: FirebaseExtended/action-hosting-deploy@v0
        with:
          repoToken: '${{ secrets.GITHUB_TOKEN }}'
          firebaseServiceAccount: '${{ secrets.FIREBASE_SERVICE_ACCOUNT }}'
          channelId: live
          projectId: your-firebase-project-id
        env:
          FIREBASE_CLI_PREVIEWS: hostingchannels

Deploying to the live channel requires channelId set to live. If left blank the action creates a new preview channel using the PR-branch name.

Additional option for the preview channel is expires which defaults to 7 days. Change the expiration of your preview channel to maximum 30 days. It supports the syntax h for hours, d for days and w for weeks, for example 19h, 30d, 3w.

Preview and Live Channel

Create a Pull Request with the above GitHub workflows and you should see the GitHub Action start building

After the workflow finished successfully, the Firebase action creates a comment with the preview URL for this PR.

View the preview of your web app, if you are not happy with your changes repeat it. Here is the Scully demo blog in the preview channel on Firebase Hosting.

Finally, merge your Pull Request to trigger the deployment to the live channel. Find the Scully demo blog on the live channel.

It was never easier to ship improvements to your web application to preview, ask colleagues or customers for a review 👌❓ and simply deploy your changes to the live channel 🚀 by merging your PR.