Generate a random available user port in Rust

main.rs

use rand::{rng, seq::SliceRandom};
use std::{
    io::Result,
    net::{IpAddr, SocketAddr, TcpListener, ToSocketAddrs},
    vec::IntoIter,
};

pub struct RandomUserPort(std::ops::RangeInclusive<u16>);

impl RandomUserPort {
    pub fn new() -> Self {
        RandomUserPort(1024..=49151)
    }

    pub fn find_port() -> Result<u16> {
        let res = TcpListener::bind(Self::new())?;
        Ok(res.local_addr()?.port())
    }
}

impl ToSocketAddrs for RandomUserPort {
    type Iter = IntoIter<SocketAddr>;

    fn to_socket_addrs(&self) -> Result<Self::Iter> {
        // You might want to use localhost (127.0.0.1) as default IP
        let ip = IpAddr::from([127, 0, 0, 1]);

        // Convert the range into a vector of SocketAddr
        let mut addrs = self
            .0
            .clone()
            .map(|port| SocketAddr::new(ip, port))
            .collect::<Vec<_>>();

        let mut rng = rng();
        addrs.shuffle(&mut rng);

        Ok(addrs.into_iter())
    }
}

fn main() {
    println!("First open port: {:?}", RandomUserPort::find_port())
}