Production Checklist

1. Build for Production

# Release build of the Rust extension
maturin develop --release --manifest-path crates/justapi-py/Cargo.toml

Cargo.toml sets panic = "abort" in release mode — panics safely abort the process (no UB across PyO3 FFI).

2. Process Supervision

Run under a supervisor that restarts the process:

# systemd unit
[Service]
ExecStart=/srv/app/venv/bin/python -m myapp
Restart=always
RestartSec=1
StartLimitIntervalSec=10
StartLimitBurst=5

For Kubernetes, set restartPolicy: Always with liveness and readiness probes.

3. TLS Termination

Recommended: Terminate TLS at an edge proxy (nginx, Caddy, cloud LB):

server {
    listen 443 ssl;
    location / {
        proxy_pass http://127.0.0.1:8000;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
        client_max_body_size 1m;
    }
}

4. Request Body Size

Set the smallest value your endpoints allow:

app.run("0.0.0.0:8000", max_body_size=1024 * 1024)  # 1 MiB

Bodies over the limit receive 413 Payload Too Large.

5. Security Headers

app.enable_secure_headers(with_hsts=True)
app.add_cors(
    allow_origins=["https://yourdomain.com"],
    allow_methods=["GET", "POST"],
)

CORS is deny-by-default — no permissive * unless you configure it.

6. Health Checks

app.register_health_check("postgres", lambda: db_ok())

# Endpoints:
# GET /health  → liveness probe (200 = OK)
# GET /ready   → readiness probe (200 = all deps healthy)
# GET /live    → lightweight liveness alias

7. Metrics

# Scrape /metrics with Prometheus
curl http://localhost:8000/metrics

Key signals: request count by route/status, p50/p95/p99 latency, error ratios.

8. Timeouts

justapi serve --timeout 30  # Request timeout in seconds

Keep proxy and JustAPI timeouts aligned to avoid spurious 504s.

9. Graceful Shutdown

run() installs SIGINT/SIGTERM handlers. On signal, it:

Stops accepting new connections
Drains in-flight requests
Calls plugin shutdown hooks
Exits cleanly

Ensure your supervisor sends SIGTERM (not SIGKILL) for clean drains.