Rust Demo

Learning project for Rust ecosystem and various related technologies:

• catalog-svc - standard Rust webapp using Axum and Utoipa to generate a openapi spec + client generation

  • Rust client generation uses progenitor-client which require an OpenAPI 3.0 spec (we have to downvert from 3.1)

• catalog-svc-smithy - a variation of the above using Smithy for API generation and server.

  • use ./gradlew build to generate the types

• snippets - various code snippets to illustrate Rust features and idioms

Notes

• For cross-crate test-only helpers, prefer a test-utils cargo feature (instead of #[cfg(test)]) so shared test code can be compiled and reused where needed. See: https://stackoverflow.com/questions/41700543/can-we-share-test-utilities-between-crates

Building

• Smithy types (Gradle): just generate-smithy
• Build Rust service: cargo clippy --all-targets -- --deny warnings
  • Formatting cargo +nightly fmt
• OpenAPI spec (from Rust server code): just generate-openapi
• Frontent / Typescript:
  • Initial setup: nvm install && nvm use && npm ci
  • TypeScript client (from OpenAPI spec): just generate-ts-client
  • just build-frontend

Running the app

1. Start dependencies (Postgres, Kafka):

   just start-docker-deps

2. Run the catalog service (listens on http://localhost:3030):

   CONFIG_FILE=catalog-svc/catalog-svc/config.toml cargo run -p catalog-svc --bin catalog-svc

3. Install dependencies and start the dev server:

   cd frontend
   npm run dev

   The dev server starts at http://localhost:5173 by default. It expects the backend to be running on port 3030.

Running via Docker

The repo ships a multi-stage Dockerfile that builds the Rust service and the frontend, then bundles them into a distroless runtime image. The service binds to 0.0.0.0:3030 by default and serves the built frontend from /app/public.

1. Build the image (BuildKit is required for the cache mounts):

    docker build -t catalog-svc:local .

2. Start the dependencies the service needs (Postgres on :5432, Kafka on :9092):

   just start-docker-deps

3. Run the image. The bundled config.toml points postgres at localhost, which won't resolve from inside the container, so override the host via env vars. From a Linux host with the compose deps running on the host network:

   docker run --rm --network host -e APP__POSTGRES__HOST=localhost catalog-svc:local

   On macOS/Windows (no --network host), publish the port and point Postgres at the host gateway:

   docker run --rm -p 3030:3030 -e APP__POSTGRES__HOST=host.docker.internal catalog-svc:local

TODO:

• Job scheduler, Cron scheduler
• Kafka?
• Add Kubernetes stuff