Build 6 — Deploy to Production

# Build 6 — Deploy to Production ## The brief Take a previous build (Notes API, URL shortener, etc.) and deploy it to a real cloud platform with proper config, migrations, HTTPS, and a custom domain. ## Step 1: Pick a platform For this walkthrough: Fly.io (free tier, fast, full control). Alternatives: - Railway (simpler). - Render (Heroku-like). - Northflank, Koyeb (other Heroku-alternatives). Or: AWS Fargate, GCP Cloud Run for more control. ## Step 2: Dockerize (15 min) ```dockerfile # Dockerfile FROM python:3.12-slim AS builder WORKDIR /app COPY --from=ghcr.io/astral-sh/uv:latest /uv /usr/local/bin/uv COPY pyproject.toml uv.lock ./ RUN uv sync --frozen --no-dev FROM python:3.12-slim WORKDIR /app COPY --from=builder /app/.venv /app/.venv COPY src ./src COPY alembic alembic COPY alembic.ini ./ ENV PYTHONUNBUFFERED=1 ENV PATH="/app/.venv/bin:$PATH" EXPOSE 8000 CMD ["sh", "-c", "alembic upgrade head && uvicorn notes_api.main:app --host 0.0.0.0 --port 8000 --workers 4"] ``` Test locally: ```bash docker build -t my-api . docker run -p 8000:8000 -e DATABASE_URL=sqlite:///./test.db my-api ``` ## Step 3: Fly.io setup (15 min) ```bash brew install flyctl fly auth signup # or login fly launch # interactive setup ``` Generates `fly.toml`: ```toml app = "my-notes-api" primary_region = "bom" # Mumbai [build] dockerfile = "Dockerfile" [env] LOG_LEVEL = "INFO" [http_service] internal_port = 8000 force_https = true auto_stop_machines = true auto_start_machines = true min_machines_running = 0 # for free tier; scale up for prod [[services.tcp_checks]] grace_period = "5s" interval = "15s" timeout = "2s" ``` ## Step 4: Provision a Postgres database (10 min) ```bash fly postgres create --name my-notes-db --region bom fly postgres attach --app my-notes-api my-notes-db ``` Auto-sets DATABASE_URL secret on your app. Alternative: Supabase or Neon for managed Postgres outside Fly. ## Step 5: Set secrets (5 min) ```bash fly secrets set \ SECRET_KEY=$(openssl rand -hex 32) \ LOG_LEVEL=INFO \ --app my-notes-api ``` NEVER commit these. fly.io stores them encrypted. ## Step 6: Deploy (10 min) ```bash fly deploy ``` Logs to terminal. After deploy: ```bash fly status fly logs fly open # opens in browser ``` Access: - https://my-notes-api.fly.dev - https://my-notes-api.fly.dev/docs (Swagger UI) ## Step 7: Migrations (5 min) The Dockerfile runs `alembic upgrade head` at start. For separate migration runs: ```bash fly ssh console alembic upgrade head ``` Or run as a release command in `fly.toml`: ```toml [deploy] release_command = "alembic upgrade head" ``` ## Step 8: Custom domain (5 min) ```bash fly certs add api.mydomain.com # Add CNAME at your DNS provider pointing to .fly.dev # Fly auto-provisions Let's Encrypt cert ``` After DNS propagates: ```bash fly certs check api.mydomain.com ``` ## Step 9: Setup CI for auto-deploy (15 min) `.github/workflows/deploy.yml`: ```yaml name: Deploy on: push: branches: [main] jobs: deploy: runs-on: ubuntu-latest steps: - uses: actions/checkout@v4 - uses: actions/setup-python@v5 with: python-version: '3.12' - run: pip install pytest httpx - run: pytest - name: Deploy to Fly run: curl -L https://fly.io/install.sh | sh && /home/runner/.fly/bin/flyctl deploy --remote-only env: FLY_API_TOKEN: ${{ secrets.FLY_API_TOKEN }} ``` Generate Fly token: ```bash fly auth token ``` Add as GitHub secret `FLY_API_TOKEN`. Now every push to main: tests run; if green, deploy. ## Step 10: Monitoring (10 min) ```bash fly logs # tail logs fly status # check instance health fly metrics # view dashboards ``` For richer observability: - Add Sentry for error tracking. - Ship logs to Loki / Datadog. - Add OpenTelemetry for traces. Sentry setup: ```python import sentry_sdk sentry_sdk.init(dsn=settings.sentry_dsn, traces_sample_rate=0.1) ``` ## Deliverables - Live URL of your deployed API. - Working /docs endpoint. - HTTPS with valid cert. - Database persistence. - CI auto-deploy on push to main. - A `DEPLOY.md` documenting the steps. ## What you'll learn - Multi-stage Dockerfile for slim production images. - Cloud platform basics (Fly.io as example). - Managed Postgres provisioning. - Secrets management. - Custom domains + HTTPS via Let's Encrypt. - CI/CD pipeline that tests + deploys. ## Stretch - Deploy to multiple regions (Fly auto-supports). - Add a CDN (Cloudflare in front). - Set up Sentry for error tracking. - Add metrics dashboard (Grafana + Prometheus). - Configure auto-scaling based on traffic.