`.github/workflows/pr-preview.yml`

146 lines
name: PR Preview

# Alchemy preview stage per private-repo PR: deploy on open/update, destroy on
# close (stage pr-<n>). Full model in docs/PREVIEW_DEPLOYMENTS.md.
#
# Public-mirror (every-app/open-seo) PRs NEVER deploy from CI — fork code must
# not run with deploy secrets. Preview those locally from a worktree instead
# (docs/PREVIEW_DEPLOYMENTS.md, "Public-mirror PRs"). The repository gate
# below keeps the synced copy of this file inert on the mirror.
#
# Required repo secrets: CLOUDFLARE_API_TOKEN (Workers Scripts/KV/D1/R2/
# Workflows write + Secrets Store read + Account Settings read — the last two
# are how alchemy fetches its state-store token via an edge-preview worker),
# CLOUDFLARE_ACCOUNT_ID, ENV_PREVIEW (.env.preview contents).

on:
  pull_request:
    types: [opened, synchronize, reopened, closed]
    # Skip PRs that can't change the deployed worker. Filters see the PR's
    # full file list, so deploy and close-time destroy stay consistent.
    paths-ignore:
      - "**/*.md"
      - docs/**
      - runbooks/**
      - .agents/**
      - web/**
      - badseo/**

# A newer push supersedes any in-flight deploy for the same PR (alchemy's
# per-resource state reconciles cleanly on the next run); a close-triggered
# destroy never cancels — it queues behind whatever is running.
concurrency:
  group: pr-preview-${{ github.event.pull_request.number }}
  cancel-in-progress: ${{ github.event.action != 'closed' }}

permissions:
  contents: read
  pull-requests: write

env:
  STAGE: pr-${{ github.event.pull_request.number }}
  CLOUDFLARE_API_TOKEN: ${{ secrets.CLOUDFLARE_API_TOKEN }}
  CLOUDFLARE_ACCOUNT_ID: ${{ secrets.CLOUDFLARE_ACCOUNT_ID }}

jobs:
  preview:
    if: >-
      github.repository == 'bensenescu/open-seo' &&
      github.event.pull_request.head.repo.full_name == github.repository
    runs-on: ubuntu-latest
    timeout-minutes: 20

    steps:
      - name: Checkout
        uses: actions/checkout@v4
        with:
          ref: ${{ github.event.pull_request.head.sha }}

      - name: Setup pnpm
        uses: pnpm/action-setup@v4

      - name: Setup Node.js
        uses: actions/setup-node@v4
        with:
          node-version: 22
          cache: pnpm

      - name: Install dependencies
        run: pnpm install --frozen-lockfile

      - name: Write .env.preview
        run: printf '%s' "$ENV_PREVIEW" > .env.preview
        env:
          ENV_PREVIEW: ${{ secrets.ENV_PREVIEW }}

      # Derive the preview URL once, before spending a deploy on a broken
      # secret. Destroy runs don't need it.
      - name: Derive preview URL
        if: github.event.action != 'closed'
        run: |
          subdomain=$(grep '^WORKERS_SUBDOMAIN=' .env.preview | cut -d= -f2-)
          case "$subdomain" in
            *.workers.dev) ;;
            *) echo "::error::ENV_PREVIEW secret is missing a valid WORKERS_SUBDOMAIN (needed to derive and verify the preview URL)"; exit 1 ;;
          esac
          echo "PREVIEW_URL=https://open-seo-${STAGE}.${subdomain}" >> "$GITHUB_ENV"

      # Same command as a local preview deploy: vite build, alchemy deploy.
      # State lives in the account's Cloudflare state store; CI resolves its
      # auth token from the Secrets Store each run. The Access gate protecting
      # previews is one-time local setup (pnpm preview:access) — the verify
      # step below fails the job if it's ever missing.
      - name: Deploy preview stage
        if: github.event.action != 'closed'
        run: pnpm deploy:preview --stage "$STAGE" --yes
        env:
          NODE_OPTIONS: --max-old-space-size=4096

      # Fail the job (and skip the URL comment) if the deployed preview
      # answers without a Cloudflare Access login redirect. A definitive app
      # response (2xx/3xx, no Access redirect) fails immediately — the
      # preview is public; retries are only for propagation-era errors.
      # (Cloudflare version preview URLs sit outside this wildcard, but alchemy
      # uploads versions with no preview provisioned, so none are served — see
      # docs/PREVIEW_DEPLOYMENTS.md.)
      - name: Verify Access protection
        if: github.event.action != 'closed'
        run: |
          for attempt in 1 2 3 4 5 6 7 8; do
            response=$(curl -sS -o /dev/null -m 10 -w '%{http_code} %{redirect_url}' "$PREVIEW_URL") || response=""
            code="${response%% *}"
            location="${response#* }"
            case "$location" in
              https://*.cloudflareaccess.com/cdn-cgi/access/login*)
                exit 0 ;;
            esac
            if [ -n "$code" ] && [ "$code" -ge 200 ] && [ "$code" -lt 500 ]; then
              echo "::error::$PREVIEW_URL responded (HTTP $code) WITHOUT a Cloudflare Access challenge — the preview is public; destroy the stage (pnpm destroy:preview --stage $STAGE --yes)"
              exit 1
            fi
            echo "attempt $attempt: not up yet (${response:-no response})"
            sleep 5
          done
          echo "::error::$PREVIEW_URL is unreachable (likely workers.dev propagation) — it still sits behind the wildcard Access app; re-run this job or verify manually"
          exit 1

      - name: Destroy preview stage
        if: github.event.action == 'closed'
        run: pnpm destroy:preview --stage "$STAGE" --yes

      # PREVIEW_URL comes from the derive step's $GITHUB_ENV write; this step
      # only runs after verify succeeds (no `if:`, so default success() gating).
      - name: Comment on PR
        env:
          GH_TOKEN: ${{ github.token }}
          PR: ${{ github.event.pull_request.number }}
        run: |
          if [ "${{ github.event.action }}" = "closed" ]; then
            body=$(printf '**Preview destroyed** (stage `%s`).' "$STAGE")
          else
            body=$(printf '**Preview deployed** (stage `%s`): %s\n_Updated for %s. Torn down automatically when this PR closes._' \
              "$STAGE" "$PREVIEW_URL" "${{ github.event.pull_request.head.sha }}")
          fi
          gh pr comment "$PR" --repo "${{ github.repository }}" \
            --body "$body" --edit-last --create-if-none