PR Review Apps on Fly.io

This GitHub action wraps the Fly.io CLI to automatically deploy pull requests to fly.io for review. These are useful for testing changes on a branch without having to setup explicit staging environments.

This action will create, deploy, and destroy Fly apps. Just set an Action Secret for FLY_API_TOKEN.

If you have an existing fly.toml in your repo, this action will copy it with a new name when deploying. By default, Fly apps will be named with the scheme pr-{number}-{repo_org}-{repo_name}.

Inputs

name	description
name	The name of the Fly app. Alternatively, set the env FLY_APP. For safety, must include the PR number. Example: myapp-pr-${{ github.event.number }}. Defaults to pr-{number}-{repo_org}-{repo_name}.
image	Optional pre-existing Docker image to use
config	Optional path to a custom Fly toml config. Config path should be relative to path parameter, if specified.
region	Which Fly region to run the app in. Alternatively, set the env FLY_REGION. Defaults to iad.
org	Which Fly organization to launch the app under. Alternatively, set the env FLY_ORG. Defaults to personal.
path	Path to run the flyctl commands from. Useful if you have an existing fly.toml in a subdirectory.
postgres	Optional name of an existing Postgres cluster to flyctl postgres attach to.
update	Whether or not to update this Fly app when the PR is updated. Default true.
secrets	Secrets to be set on the app at runtime. Separate multiple secrets with a space
build_args	Optional Docker --build-arg
build_secrets	Optional Docker --build-secret
vmsize	Set app VM to a named size, eg. shared-cpu-1x, dedicated-cpu-1x, dedicated-cpu-2x etc. Takes precedence over cpu, cpu kind, and memory inputs.
cpu	Set app VM CPU (defaults to 1 cpu). Default 1.
cpukind	Set app VM CPU kind - shared or performance. Default shared.
memory	Set app VM memory in megabytes. Default 256.
ha	Create spare machines that increases app availability. Default false.

Required Secrets

FLY_API_TOKEN - Required. The token to use for authentication. You can find a token by running flyctl auth token or going to your user settings on fly.io.

Basic Example

name: Staging App
on:
  pull_request:
    types: [opened, reopened, synchronize, closed]

env:
  FLY_API_TOKEN: ${{ secrets.FLY_API_TOKEN }}
  FLY_REGION: iad
  FLY_ORG: personal

jobs:
  staging_app:
    runs-on: ubuntu-latest

    # Only run one deployment at a time per PR.
    concurrency:
      group: pr-${{ github.event.number }}

    # Create a GitHub deployment environment per staging app so it shows up
    # in the pull request UI.
    environment:
      name: pr-${{ github.event.number }}
      url: ${{ steps.deploy.outputs.url }}

    steps:
      - uses: actions/checkout@v4

      - name: Deploy
        id: deploy
        uses: superfly/fly-pr-review-apps@1.3.0

Cleaning up GitHub environments

This action will destroy the Fly app, but it will not destroy the GitHub environment, so those will hang around in the GitHub UI. If this is bothersome, use an action like strumwolf/delete-deployment-environment to delete the environment when the PR is closed.

on:
  pull_request:
    types: [opened, reopened, synchronize, closed]

# ...

jobs:
  staging_app:
    # ...

    # Create a GitHub deployment environment per review app.
    environment:
      name: pr-${{ github.event.number }}
      url: ${{ steps.deploy.outputs.url }}

    steps:
      - uses: actions/checkout@v4

      - name: Deploy app
        id: deploy
        uses: superfly/fly-pr-review-apps@1.3.0

      - name: Clean up GitHub environment
        uses: strumwolf/delete-deployment-environment@v2
        if: ${{ github.event.action == 'closed' }}
        with:
          # ⚠️ The provided token needs permission for admin write:org
          token: ${{ secrets.GITHUB_TOKEN }}
          environment: pr-${{ github.event.number }}

Example with Postgres cluster

If you have an existing Fly Postgres cluster you can attach it using the postgres action input. flyctl postgres attach will be used, which automatically creates a new database in the cluster named after the Fly app and sets DATABASE_URL.

For production apps, it's a good idea to create a new Postgres cluster specifically for staging apps.

# ...
steps:
  - uses: actions/checkout@v4

  - name: Deploy app
    id: deploy
    uses: superfly/fly-pr-review-apps@1.3.0
    with:
      postgres: myapp-postgres-staging-apps

Example with multiple Fly apps

If you need to run multiple Fly apps per staging app, for example Redis, memcached, etc, just give each app a unique name. Your application code will need to be able to discover the app hostnames.

Redis example:

steps:
  - uses: actions/checkout@v4

  - name: Deploy redis
    uses: superfly/fly-pr-review-apps@1.3.0
    with:
      update: false # Don't need to re-deploy redis when the PR is updated
      path: redis # Keep fly.toml in a subdirectory to avoid confusing flyctl
      image: flyio/redis:6.2.6
      name: pr-${{ github.event.number }}-myapp-redis

  - name: Deploy app
    id: deploy
    uses: superfly/fly-pr-review-apps@1.3.0
    with:
      name: pr-${{ github.event.number }}-myapp-app