Very tiny suggestion about Rust grammar

[fzyzcjy]

@y-young

When very briefly wandering around this project, attracted by @y-young, I see a very very tiny issue, and just post it here as a small practice to Rust:

rMiniK8s/controllers/src/ingress/nginx_ingress_config.rs

Line 101 in 35b2c30

pub fn add_path(&mut self, path: &String, svc_ip: &Ipv4Addr, svc_port: &u16) {

    pub fn add_path(&mut self, path: &String, svc_ip: &Ipv4Addr, svc_port: &u16) {
        self.paths.push(IngressPath {
            path: path.to_owned(),
            ip: svc_ip.to_owned(),
            port: svc_port.to_owned(),
        });
    }

I am not sure about the following:

1. Is &str better than &String?
2. Is u16 more efficient than &u16 when passing an argument?
3. If the user of this method do not need path/src_ip anymore, currently the add_path still makes a copy of it. If we change the signature to path: String and remove to_owned(), maybe we can remove a memory copy in such case.