Architectural Best Practices & Production

This chapter covers:

1. Adhere to Thin Controller / Fat Service conventions;
2. Tune database connection pool sizes, index prefixes, and cursor pagination;
3. Enforce production security policies and secrets hygiene;
4. Deploy Foundry applications with multi-stage Dockerfiles and Docker Compose.

• Thin Controller / Fat Service: Keep handlers restricted to deserialization, validation, and serialization. Keep domain rules inside logic/.
• Explicit Validation: Always call payload.validate()? before business logic execution.
• Compound Indexes: Always make system_id the first column in multi-tenant composite indexes (IndexDef).
• Cursor Pagination: For large tables, avoid deep OFFSET. Use WHERE id > $last_id LIMIT $n.

FROM rust:1.85-alpine AS builder
WORKDIR /app
RUN apk add --no-cache musl-dev openssl-dev pkgconfig
COPY Cargo.toml Cargo.lock ./
COPY src ./src
RUN cargo build --release

FROM alpine:3.20
WORKDIR /app
RUN apk add --no-cache ca-certificates libgcc
COPY --from=builder /app/target/release/my-app /app/server
COPY .env.example /app/.env
EXPOSE 8080
CMD ["/app/server"]

• Development & CI: AUTO_MIGRATE=true for zero-friction schema creation.
• Production: AUTO_MIGRATE=false. Export offline migration scripts via foundry ddl --db <type> into migrations/init.sql for DBA auditing and controlled deployment.