Go Learning Agenda (Juju’s Challenge)

Build an HTTP API responsible for handling a phone agenda (contacts). The goal is not the features themselves, but the engineering decisions along the way: configuration, API design, testing, logging/metrics, persistence, and containerization.

General

  • [x] The HTTP service should be configurable through flags on startup (timeouts and port to use)

Endpoints

  • [x] Endpoint to create a contact
  • [x] Endpoint to edit contact information
  • [x] Endpoint to delete a contact
  • [x] Endpoint to get a contact by id
  • [x] Endpoint to search contacts by partial name
  • [x] Endpoint to list all contacts

Tests

  • [ ] Target reasonable coverage (≥ 70%) with table-driven tests
  • [ ] Add end-to-end tests that hit the real HTTP server (good chance to try an HTTP client)

Logs & Metrics

  • [ ] Log one line per request: method, path, status code, latency
  • [ ] On error, log status and a helpful message to aid troubleshooting
  • [ ] Collect service and host metrics (suggestion: Prometheus) (prometheus go app guide)

Containerization and Storage

  • [ ] Include a buildable Dockerfile (note: pure scratch images may break HTTPS requests; be mindful for real-world needs) (reference)
  • [x] Persist data with any storage solution you prefer (file, SQLite, Postgres, etc.)

Suggested learning path

  1. CLI & configuration: flags, env, and sane defaults.
  2. HTTP server: handlers, context, timeouts, graceful shutdown.
  3. Validation & errors: structured errors and proper HTTP status mapping.
  4. Data layer: interface-driven repository with an in-memory impl first, then swap to a real store.
  5. Testing: table-driven unit tests; e2e tests booting the server on a random port.
  6. Observability: middleware for request logging and Prometheus metrics.
  7. Containerization: multi-stage build; minimal runtime image; healthcheck.
  8. Extras: rate limiting, request IDs, pprof.

FIX

  • [x] Avoid stutter like Phonebook.InsertPhonebook; use Phonebook.Insert instead
  • [x] Fix database configuration
  • [ ] Add better user-facing/API error feedback (consistent JSON error schema)