Add action to deploy PRs to preview app.

Author: alflanagan

.github/workflows/fly-preview.yml

@@ -0,0 +1,35 @@
+name: Deploy Review App
+on:
+  # Run this workflow on every PR event. Existing review apps will be updated when the PR is updated.
+  pull_request:
+    types: [opened, reopened, synchronize, closed]
+
+env:
+  FLY_API_TOKEN: ${{ secrets.FLY_API_TOKEN }}
+  # Set these to your Fly.io organization and preferred region.
+  FLY_REGION: iad
+  FLY_ORG: a-lloyd-flanagan-he-him
+
+jobs:
+  review_app:
+    runs-on: ubuntu-latest
+    outputs:
+      url: ${{ steps.deploy.outputs.url }}
+    # Only run one deployment at a time per PR.
+    concurrency:
+      group: pr-${{ github.event.number }}
+
+    # Deploying apps with this "review" environment allows the URL for the app to be displayed in the PR UI.
+    # Feel free to change the name of this environment.
+    environment:
+      name: review
+      # The script in the `deploy` sets the URL output for each review app.
+      url: ${{ steps.deploy.outputs.url }}
+    steps:
+      - name: Get code
+        uses: actions/checkout@v4
+
+      - name: Deploy PR app to Fly.io
+        id: deploy
+        uses: superfly/[email protected]
+