diegosouzapw Cloud-Native Development
Domain Constraints
| Domain Rule | Design Constraint | Rust Implication |
|---|---|---|
| 12-Factor | Config from env | Environment-based config |
| Observability | Metrics + traces | tracing + opentelemetry |
| Health checks | Liveness/readiness | Dedicated endpoints |
| Graceful shutdown | Clean termination | Signal handling |
| Horizontal scale | Stateless design | No local state |
| Container-friendly | Small binaries | Release optimization |
Critical Rules
- No local persistent state — pods can be killed/rescheduled anytime. Use external state (Redis, DB).
- Handle SIGTERM, drain connections — zero-downtime deployments require graceful shutdown.
- Every request must be traceable — distributed systems need tracing spans + opentelemetry export.
Key Crates
| Purpose | Crate |
|---|---|
| gRPC | tonic |
| Kubernetes | kube, kube-runtime |
| Docker | bollard |
| Tracing | tracing, opentelemetry |
| Metrics | prometheus, metrics |
| Config | config, figment |
Graceful Shutdown Pattern
use tokio::signal;
async fn run_server() -> anyhow::Result<()> {
let app = Router::new()
.route("/health", get(health))
.route("/ready", get(ready));
let addr = SocketAddr::from(([0, 0, 0, 0], 8080));
axum::Server::bind(&addr)
.serve(app.into_make_service())
.with_graceful_shutdown(shutdown_signal())
.await?;
Ok(())
}
async fn shutdown_signal() {
signal::ctrl_c().await.expect("failed to listen for ctrl+c");
tracing::info!("shutdown signal received");
}
Health Check Pattern
async fn health() -> StatusCode {
StatusCode::OK
}
async fn ready(State(db): State<Arc<DbPool>>) -> StatusCode {
match db.ping().await {
Ok(_) => StatusCode::OK,
Err(_) => StatusCode::SERVICE_UNAVAILABLE,
}
}
Common Mistakes
| Mistake | Domain Violation | Fix |
|---|---|---|
| Local file state | Not stateless | External storage |
| No SIGTERM handling | Hard kills | Graceful shutdown |
| No tracing | Can't debug | tracing spans |
| Static config | Not 12-factor | Env vars |