todo-ddd-example

todo-ddd-example

Stack

• Architecture: Follows/Inspired by Clean Architecture with DDD and basic CQRS. Caching, tracing and auditing via decorators with gowrap.
• Database: PostgreSQL with pgroll for zero-downtime schema migrations. sqlc for type-safe queries.
• API: Contract-first via OpenAPI 3.0 with oapi-codegen.
  • Automatic request/response validation.
  • Spec-defined rate limiting.
  • Idempotency keys to let clients safely handle non-idempotent request retries.
• Observability: OpenTelemetry with Jaeger and Prometheus.
• Messaging: RabbitMQ for events and Redis PubSub for cross-node WebSocket synchronization. Transactional outbox pattern with at-least-once delivery.
• Tooling: Custom generated CLI client from the OpenAPI spec with completion if using direnv.
• Infra: Kubernetes or Docker swarm.
• Load testing: via k6.
• CI: See .github/workflows/tests.yaml.

Setup

make deploy

Test

make test

Web UIs

• API docs: http://127.0.0.1:8090/api/v1/docs
• Jaeger: http://jaeger.localhost:8090/
• Prometheus: http://prometheus.localhost:8090/
• RabbitMQ: http://rabbitmq.localhost:8090/

Example API usage

Full flow with MFA via generated todo-cli client:

scripts/example-flow.sh # with local swarm
# or
API_URL="http://localhost:8099" scripts/example-flow.sh # with make dev

Websockets and message queues

First register, login and create a workspace:

./todo-cli register -p '{"email": "user@example.com", "name": "User", "password": "Password123!"}'
export API_TOKEN=$(./todo-cli login -p '{"email": "user@example.com", "password": "Password123!"}' | jq -r .accessToken)

export WS_ID=$(./todo-cli onboard-workspace -p '{"name": "My Workspace"}' | jq -r .id)

Websockets:

$ make ws-listen
>>> Connected (press CTRL+C to quit)
# < {"event":"todo.created","id":"ae1e2ddc-5880-4f9a-8c3f-1d1fae16fbd8","status":"PENDING","title":"New todo 1770748039"}
# < {"event":"todo.updated","id":"ae1e2ddc-5880-4f9a-8c3f-1d1fae16fbd8","status":"COMPLETED","title":"New todo 1770748039"}
$ ./todo-cli create-todo $WS_ID -p '{"title": "New todo"}'
{"id":"ae1e2ddc-5880-4f9a-8c3f-1d1fae16fbd8"}
...
$ ./todo-cli complete-todo ae1e2ddc-5880-4f9a-8c3f-1d1fae16fbd8
...
$ ./todo-cli get-workspace-todos $WS_ID
>>> [{"id":"ae1e2ddc-5880-4f9a-8c3f-1d1fae16fbd8",...}]

Rabbitmq messages:

$ make rabbitmq-watch
>>> Tailing live events on 'todo_events'...
...

$ ./todo-cli complete-todo $(./todo-cli create-todo $WS_ID -p '{"title": "New todo"}' | jq -r .id)
# ...will show "todo.created" and "todo.completed" messages in watcher