# Quickstart: Production API Container Image

## Prerequisites

- Docker 24+ installed and running on the host
- `make` available
- A copy of `.env` (or the env vars from `.env.example`) for smoke-testing

---

## Build the Production Image

```sh
make build-prod
# Equivalent: docker build -f api/Dockerfile.prod api/ -t reactbin-api-prod:latest
```

On a warm cache (deps unchanged), the build should complete in under 60 seconds because the dependency layer is reused.

---

## Verify the Production Image (TDD Smoke Test)

```sh
make verify-prod
```

This runs `api/tests/build/verify_production_image.sh`, which:
1. Builds the image (fails fast if `Dockerfile.prod` is missing — the **red** TDD state)
2. Starts the container with test env vars
3. Polls `/api/v1/health` until it returns 200 (or times out after 30s)
4. Asserts the API process is running as a non-root user (UID ≠ 0)
5. Sends SIGTERM and asserts the container exits with code 0 within 30s
6. Asserts `pytest` is NOT importable inside the container (dev deps excluded)

**Expected output (green)**:
```
[verify] Building reactbin-api-prod:test ...
[verify] Build OK
[verify] Starting container ...
[verify] Health check passed (GET /api/v1/health → 200)
[verify] Process user: 1001 (non-root ✓)
[verify] Sending SIGTERM ...
[verify] Container exited with code 0 (graceful shutdown ✓)
[verify] Dev deps absent ✓
[verify] All checks passed.
```

---

## User Story Integration Scenarios

### US1 — API Runs Reliably in Production

```sh
# Start container with real (or test) env vars
docker run --rm -d \
  --name reactbin-test \
  -p 8000:8000 \
  -e JWT_SECRET_KEY=my-secret \
  -e OWNER_USERNAME=owner \
  -e OWNER_PASSWORD=changeme \
  -e DATABASE_URL=postgresql+asyncpg://user:pass@host:5432/db \
  -e S3_ENDPOINT_URL=http://minio:9000 \
  -e S3_BUCKET_NAME=reactbin \
  -e S3_ACCESS_KEY_ID=minioadmin \
  -e S3_SECRET_ACCESS_KEY=minioadmin \
  -e S3_REGION=us-east-1 \
  reactbin-api-prod:latest

# Check health
curl http://localhost:8000/api/v1/health
# → {"status":"ok"}

# Graceful shutdown
docker stop reactbin-test     # sends SIGTERM
docker wait reactbin-test     # → exit code 0
```

### US2 — Minimal, Secure Container

```sh
# Verify non-root user
docker inspect --format='{{.Config.User}}' reactbin-api-prod:latest
# → appuser (or 1001)

# Verify no dev packages (pytest should not be importable)
docker run --rm reactbin-api-prod:latest \
  /app/.venv/bin/python -c "import pytest" 2>&1
# → ModuleNotFoundError: No module named 'pytest'

# Verify no source control or test files in image
docker run --rm reactbin-api-prod:latest ls /app
# → app  .venv   (no tests/, no alembic/, no .git/)
```

### US3 — Fast, Reproducible Builds

```sh
# First build (cold): installs all deps
time docker build --no-cache -f api/Dockerfile.prod api/ -t reactbin-api-prod:cold

# Touch a source file only (no dep change)
touch api/app/main.py

# Second build: dependency layer served from cache
time docker build -f api/Dockerfile.prod api/ -t reactbin-api-prod:warm
# Expect: warm build < 30s; cold build varies (network-dependent)

# Confirm same health response from both
docker run --rm ... reactbin-api-prod:cold
docker run --rm ... reactbin-api-prod:warm
```

---

## Missing Env Var Behaviour

```sh
docker run --rm \
  -e JWT_SECRET_KEY=my-secret \
  # OWNER_USERNAME intentionally omitted
  reactbin-api-prod:latest
# → Container exits non-zero, stderr logs: "field required: owner_username"
```

---

## Read-Only Filesystem Compatibility

```sh
docker run --rm --read-only \
  -e JWT_SECRET_KEY=... [other env vars] \
  reactbin-api-prod:latest &

curl http://localhost:8000/api/v1/health
# → {"status":"ok"}
```
