Tries to use a terminal when running under Docker, and causes requests to fail

[emk]

If I take a basic Iron app with logger 0.0.3:

fn main() {
    // Set up very basic logging to the console.
    env_logger::init();

    // Declare our REST API using Rustless, which is much tidier than using
    // bare Iron APIs.
    let api = rustless::Api::build(|api| {
        // ... SNIPPED  ...
    });
    let app = rustless::Application::new(api);

    // Put our app into a middleware chain so we can attach the logger,
    // etc.
    let mut chain = Chain::new(app);

    // Call the logger middleware at the beginning and end of our request
    // chain.
    let (logger_before, logger_after) = Logger::new(None);
    chain.link_before(logger_before);
    chain.link_after(logger_after);

    // Run our web server.
    println!("Listening on 0.0.0.0:3000");
    match Iron::new(chain).http("0.0.0.0:3000") {
        Ok(_) => {},
        Err(ref e) => println!("Could not start server: {}", e),
    }
}

…and run it under Docker as:

docker run --rm myimage

I get:

ERROR:iron::iron: Error handling:
Request {
    url: Url { scheme: "http", host: Ipv4(172.17.0.11), port: 3000, path: ["health"], username: None, password: None, query: None, fragment: None }
    method: Get
    remote_addr: V4(172.17.42.1:35256)
    local_addr: V4(0.0.0.0:3000)
}
Error was: CouldNotOpenTerminal

Running docker run --rm myimage env does not show the TERM variable as being set. But it looks like it's trying to open a terminal anyway, instead of just logging to stdout.

There's probably a way to reproduce this without docker; I'm investigating further.

[emk]

Ah, a nice easy repro: Just run unset TERM and launch an example server.

[cholcombe973]

I just ran into this also :-/

[ChrisMacNaughton]

This happens under Upstart as well

[tomprince]

I think this is no longer relevant, now that it logs via the log crate.