DNS problems with ureq on github.com in rootless Docker container built with muslrust

[KonradHoeffner]

DNS problems with ureq on github.com in rootless Docker container built with muslrust

[jsha]

Thanks for reporting! A couple of questions: - does this reproduce with another Rust http client in the same container? - if you write a minimal rust program that does just a DNS lookup, does that also fail?

[KonradHoeffner]

I've now written a minimal Rust program with ureq at https://github.com/KonradHoeffner/mwedns that does indeed fail at the DNS lookup step:

$ git clone [email protected]:KonradHoeffner/mwedns.git --branch ureq
$ cd mwedns
$ docker build . -t mwedns
[...]
$ docker run --rm mwedns
Trying to resolve google.com with to_socket_addrs()
it worked
Trying to get google.com with ureq
it worked
Trying to resolve github.com with to_socket_addrs()
thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: Custom { kind: Uncategorized, error: "failed to lookup address information: Name does not resolve" }', src/main.rs:8:51

main.rs

use std::net::ToSocketAddrs;

fn main() {
    let domains = ["google.com", "github.com"];
    for domain in domains
    {
        println!("Trying to resolve {domain} with to_socket_addrs()");
        format!("{domain}:443").to_socket_addrs().unwrap();
        println!("it worked");
        println!("Trying to get {domain} with ureq");
        ureq::get(&format!("https://{domain}")).call().unwrap().into_reader();
        println!("it worked");
    }
}

If I interpret this correctly this is nothing that ureq can do about and I should report it somewhere else? Shall I still test it with another Rust http client?

[KonradHoeffner]

I will close this question and report it at a better suited place.