smarm/tests/cluster_dial_mismatch.rs

//! RFC 010 — a seed whose address answers as a *different* name
//! (`DialError::PeerNameMismatch`) is dialed once and then parked: the
//! connector must not redial it on backoff forever.
//!
//! Observed from the misdialed peer: each such dial establishes at the
//! responder (it registers, `node_up`), then the dialer closes on the name
//! check (`node_down`) — one membership blip per attempt. Cross-process: a
//! *server* named `server` subscribes and reports; a *client* on fast
//! timing (50–500ms backoff) seeds `("wrongname", server_addr)`. After the
//! first blip the server counts further `NodeUp`s across 2s — several
//! backoff periods. Parked ⇒ zero. Negative-control-verified: with the park
//! stubbed out the count is ≥ 1 in the same window.
#![cfg(feature = "cluster")]

mod common;

use common::{maybe_child, spawn_node};
use smarm::cluster::envelope::NodeMeta;
use smarm::cluster::membership::{subscribe, NodeEvent};
use smarm::cluster::{start, Config, StaticSeeds, Timing};
use std::time::{Duration, Instant};

const ROLES: &[(&str, fn())] = &[("server", role_server), ("client", role_client)];

fn meta() -> NodeMeta {
    NodeMeta {
        role: "mismatch".into(),
        region: "local".into(),
    }
}

fn timing() -> Timing {
    Timing {
        initial_backoff: Duration::from_millis(50),
        max_backoff: Duration::from_millis(500),
        ..Timing::default()
    }
}

fn role_server() {
    smarm::run(|| {
        let cluster = start(Config {
            node_name: "server".into(),
            meta: meta(),
            listen_addr: std::env::var("SMARM_LISTEN_ADDR")
                .unwrap_or_else(|_| "127.0.0.1:0".into()),
            strategy: Box::new(StaticSeeds::new(Vec::<(String, String)>::new())),
            timing: timing(),
        })
        .expect("binds");
        let ev = subscribe().unwrap();
        println!("LISTENING {}", cluster.local_addr());
        // First blip: the misdialed client establishes, then closes on us.
        loop {
            match ev.rx.recv() {
                Ok(NodeEvent::NodeDown(i)) if i.name == "client" => break,
                Ok(_) => continue,
                Err(_) => panic!("manager gone"),
            }
        }
        println!("BLIP");
        // Now count further NodeUps across several backoff periods.
        let mut more = 0usize;
        let t0 = Instant::now();
        while t0.elapsed() < Duration::from_millis(2000) {
            match ev.rx.try_recv() {
                Ok(Some(NodeEvent::NodeUp(i))) if i.name == "client" => more += 1,
                Ok(_) => {}
                Err(_) => panic!("manager gone"),
            }
            smarm::sleep(Duration::from_millis(50));
        }
        println!("MORE {more}");
        loop {
            smarm::sleep(Duration::from_secs(3600));
        }
    });
}

fn role_client() {
    let server_addr = std::env::var("SMARM_SERVER_ADDR").expect("SMARM_SERVER_ADDR");
    smarm::run(move || {
        let _cluster = start(Config {
            node_name: "client".into(),
            meta: meta(),
            listen_addr: "127.0.0.1:0".into(),
            strategy: Box::new(StaticSeeds::new(vec![(
                "wrongname".to_string(),
                server_addr,
            )])),
            timing: timing(),
        })
        .expect("binds");
        println!("CLIENT UP");
        loop {
            smarm::sleep(Duration::from_secs(3600));
        }
    });
}

#[test]
fn mismatched_seed_is_dialed_once_then_parked() {
    maybe_child(ROLES);
    let mut server = spawn_node("server", &[]);
    let saddr = server.wait_listening();
    let mut client = spawn_node("client", &[("SMARM_SERVER_ADDR", &saddr)]);
    client.wait_line("CLIENT UP", |l| l == "CLIENT UP");
    server.wait_line("BLIP", |l| l == "BLIP");
    let line = server.wait_line("MORE", |l| l.starts_with("MORE "));
    let more: usize = line.split_whitespace().nth(1).unwrap().parse().unwrap();
    assert_eq!(
        more, 0,
        "mismatched seed was redialed {more}× after being parked"
    );
}