meetup: Add HTTP server code we wrote during September meet-up

The code and some instructions are added to the web-site.

Author: hds

content/meetups/2024-09-17.md

@@ -26,3 +26,13 @@ an HTTP server!
 
 This will be a group implementation session, where we'll do our best to get a `curl`-compliant HTTP
 server responding with something simple by the end of our lunch break.
+
+#### The result
+
+We managed to get a server working with some basic error handling as well as responding to a happy
+path request with a body. The code has been left exactly as it was at the end of the meet-up, `dbg!`
+statements and all!
+
+The code can be found on GitHub [hds/lunch.rs](https://github.com/hds/lunch.rs):
+
+- [http-for-lunch](https://github.com/hds/lunch.rs/tree/main/static/content/2024-09-17/http-for-lunch)

static/content/2024-09-17/http-for-lunch/Cargo.lock

@@ -0,0 +1,6 @@
+[package]
+name = "http-for-lunch"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]

static/content/2024-09-17/http-for-lunch/Cargo.toml

@@ -0,0 +1,48 @@
+# HTTP for Lunch
+
+This is an HTTP server which was built during the [September Rust for Lunch meetup](https://lunch.rs/meetups/2024-09-17/).
+
+The code has been left exactly as it was at the end of the meet-up, `dbg!` statements and all!
+
+## Building & running
+
+Normal `cargo` behaviour:
+
+```sh
+cargo run
+```
+
+## Testing
+
+We ran the following requests against the server.
+
+Happy path:
+
+```sh
+$ curl -D - http://127.0.0.1:8080/hello
+HTTP/1.1 200 Rust for Lunch
+Content-Length: 13
+
+Hello, World!
+```
+
+Method not allowed:
+
+```sh
+$ curl -X POST -D - http://127.0.0.1:8080/hello
+HTTP/1.1 405 Method Not Allowed
+```
+
+HTTP version not supported:
+
+```sh
+$ curl --http1.0 -D - http://127.0.0.1:8080/hello
+HTTP/1.1 505 HTTP Version not supported
+```
+
+Not found:
+
+```sh
+$ curl -D - http://127.0.0.1:8080/bye
+HTTP/1.1 404 Not Found
+```

static/content/2024-09-17/http-for-lunch/README.md

@@ -0,0 +1,80 @@
+use std::{
+    io::{self, Read, Write},
+    net::{TcpListener, TcpStream},
+};
+
+fn write_response_no_body(
+    stream: &mut TcpStream,
+    status_code: &str,
+    reason_phrase: &str,
+) -> io::Result<()> {
+    write_response(stream, status_code, reason_phrase, None)
+}
+
+fn write_response(
+    stream: &mut TcpStream,
+    status_code: &str,
+    reason_phrase: &str,
+    body: Option<&str>,
+) -> io::Result<()> {
+    let http_version = "HTTP/1.1";
+    write!(
+        stream,
+        "{http_version} {status_code} {reason_phrase}\r\n",
+    )?;
+
+    match body {
+        Some(body) => {
+            // Content length header
+            write!(stream, "Content-Length: {len}\r\n\r\n", len = body.len())?;
+         
+            write!(stream, "{body}")
+        }
+        None => write!(stream, "\r\n"),
+    }
+}
+
+fn handle_client(mut stream: TcpStream) -> std::io::Result<()> {
+    let mut buffer = vec![0_u8; 1024];
+
+    let read_len = stream.read(&mut buffer)?;
+    println!("Read some bytes: {read_len}");
+
+    let request = std::str::from_utf8(&buffer).unwrap();
+    println!("Read this data: {request}");
+    let mut lines = request.lines();
+    let request_line = lines.next().unwrap();
+    let request_parts = request_line.split_whitespace().collect::<Vec<_>>();
+
+    let [method, uri, http_version] = request_parts.as_slice() else {
+        panic!("we'll sort this out later");
+    };
+
+    dbg!(method);
+    dbg!(uri);
+    dbg!(http_version);
+
+    if *http_version != "HTTP/1.1" {
+        return write_response_no_body(&mut stream, "505", "HTTP Version not supported");
+    }
+
+    if *method != "GET" {
+        return write_response_no_body(&mut stream, "405", "Method Not Allowed");
+    }
+
+    if *uri != "/hello" {
+        return write_response_no_body(&mut stream, "404", "Not Found");
+    }
+
+    write_response(&mut stream, "200", "Rust for Lunch", Some("Hello, World!"))
+}
+
+fn main() -> std::io::Result<()> {
+    let listener = TcpListener::bind("127.0.0.1:8080")?;
+
+    // accept connections and process them serially
+    for stream in listener.incoming() {
+        handle_client(stream?).unwrap();
+    }
+    Ok(())
+}