Three Independent Rust Services

This repository holds three completely separate projects. Each is fully self-contained in its own folder — its own Cargo.toml, build, tests, Docker setup, docs, and LICENSE. They share no code and no database, and there is no Cargo workspace tying them together: cd into any folder and it builds and runs on its own. Delete any folder and the others are unaffected.

Folder	Project	Port	README
url-shortener/	URL shortener REST API (Axum + SQLite) — short codes, redirects, TTL, host blocklist, rate limiting, optional Redis cache. Architecture ›	8080	README
pastebin-service/	Zero-knowledge pastebin (Axum + SQLite) — browser AES-256-GCM, key in URL fragment, optional password, TTL, burn-after-read.	8090	README
tcp-actor-server/	Non-blocking TCP/HTTP server (Tokio, actor model) — per-connection tasks, semaphore-bounded concurrency, registry actor, lock-free metrics, graceful drain. Architecture ›	8100	README

Concurrency across the services follows one philosophy — the tool matched to the access pattern (locks, atomics, channels/actors); see url-shortener/docs/CONCURRENCY.md. A beginner's book that teaches Rust using only code from these services lives at Learn-Rust-by-Building.pdf.

Each builds and tests standalone:

cd url-shortener    && cargo test && cargo run     # serves on :8080
cd pastebin-service && cargo test && cargo run     # serves on :8090
cd tcp-actor-server && cargo test && cargo run     # serves on :8100

Each folder also ships its own Dockerfile + docker-compose.yml and a docs/ directory (architecture and, for the shortener, design/scaling notes).

The only necessarily-shared file is CI: .github/workflows/ci.yml — GitHub only reads workflows from the repo root, so it builds each service independently via a matrix (one job per folder). To remove a service, delete its folder and its matrix entry.