Rust HTTP Server From Scratch

Building an HTTP server in Rust without any frameworks — just the standard library and eventually Tokio.

How it works

A TcpListener binds to port 7878 and loops forever calling accept(). Each accepted connection gets its own OS thread. That thread reads raw bytes from the socket, parses the HTTP request line, routes to a handler, writes the response, and closes the connection.

client connects
    → accept() returns a TcpStream
    → thread spawned
    → read bytes into stack buffer
    → parse request line (METHOD PATH VERSION)
    → match path → response
    → write HTTP response bytes
    → drop TcpStream (connection closed)

Project structure

src/
  main.rs              — TcpListener accept loop, spawns one thread per connection
  server/
    mod.rs             — declares the server submodules
    http.rs            — HTTP parsing (parse_request) and response formatting (to_bytes)
    router.rs          — maps (method, path) to a Response
    blocking.rs        — handle_connection: reads socket, parses, routes, writes response

Endpoints

• GET / → 200 Hello, World!
• GET /health → 200 OK
• anything else → 404 Not Found
• malformed request → 500

Test it

cargo run
curl -v http://127.0.0.1:7878/
curl -v http://127.0.0.1:7878/health
curl -v http://127.0.0.1:7878/doesnotexist