Add a workflow (.github/workflows/deploy-preview.yml):

name: Deploy to Preview Channel

on:
  pull_request:
    # Optionally configure to run only for specific files. For example:
    # paths:
    # - "website/**"

jobs:
  build_and_preview:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
      # Add any build steps here. For example:
      # - run: npm ci && npm run build
      - uses: FirebaseExtended/action-hosting-deploy@v0
        with:
          repoToken: "${{ secrets.GITHUB_TOKEN }}"
          firebaseServiceAccount: "${{ secrets.FIREBASE_SERVICE_ACCOUNT }}"
          expires: 30d
          projectId: your-Firebase-project-ID
        env:
          FIREBASE_CLI_PREVIEWS: hostingchannels

Add a workflow (.github/workflows/deploy-prod.yml):

name: Deploy to Live Channel

on:
  push:
    branches:
      - master
    # Optionally configure to run only for specific files. For example:
    # paths:
    # - "website/**"

jobs:
  build_and_preview:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
      # Add any build steps here. For example:
      # - run: npm ci && npm run build
      - uses: FirebaseExtended/action-hosting-deploy@v0
        with:
          repoToken: "${{ secrets.GITHUB_TOKEN }}"
          firebaseServiceAccount: "${{ secrets.FIREBASE_SERVICE_ACCOUNT }}"
          expires: 30d
          projectId: your-Firebase-project-ID
          channelId: live

This is a service account JSON key.

It's important to store this token as an encrypted secret to prevent unintended access to your Firebase project. Set it in the "Secrets" area of your repository settings and add it as FIREBASE_SERVICE_ACCOUNT: https://github.com/USERNAME/REPOSITORY/settings/secrets.

Adding repoToken: "${{secrets.GITHUB_TOKEN}}" lets the action comment on PRs with the preview URL for the associated preview channel. You don't need to set this secret yourself - GitHub sets it automatically.

If you omit this option, you'll need to find the preview URL in the action's build log.

The length of time the preview channel should remain active. If left blank, the action uses the default expiry of 7 days.

The Firebase project that contains the Hosting site to which you want to deploy. If left blank, you need to check in a .firebaserc file so that the Firebase CLI knows which Firebase project to use.

The channel to deploy to. If you don't set it, the action creates a new preview channel per-PR or per-branch. If you set it to live, the action deploys to the live channel of your default Hosting site.

You usually want to leave this blank so that each PR gets its own preview channel. An exception might be that you always want to deploy a certain branch to a long-lived preview channel (for example, you may want to deploy every commit from your next branch to a preprod preview channel).

The location of your firebase.json file relative to the root of your repository. Defaults to . (the root of your repo).

Values emitted by this action that can be consumed by other actions later in your workflow

The url(s) deployed to

The time the deployed preview urls expire

A single URL that was deployed to

This repository is maintained by Googlers but is not a supported Firebase product. Issues here are answered by maintainers and other community members on GitHub on a best-effort basis.