foo.rs

extern crate openssl;

use openssl::ssl::{SslConnectorBuilder, SslMethod};
use std::net::TcpStream;

const INCLUSTER_CA_FILE: &str = "/var/run/secrets/kubernetes.io/serviceaccount/ca.crt";

fn main() {
    let mut builder = SslConnectorBuilder::new(SslMethod::tls()).expect("can't create connector");
    builder.builder_mut().set_ca_file(INCLUSTER_CA_FILE).expect("can't add root cert");
    let connector = builder.build();

    let stream = TcpStream::connect("10.30.0.1:443").expect("can't open connection");
    connector.connect("10.30.0.1", stream).expect("can't handshake");
}