Support non-static UDS client connection paths

[kriswuollett]

Feature Request

Support non-static UDS client connection paths

Motivation

Currently the UDS client example is using a static path, I believe because of the ownership requirements of the service function closure:

tonic/examples/src/uds/client.rs

Lines 16 to 28 in c30cb78

	// We will ignore this uri because uds do not use it
	// if your connector does use the uri it will be provided
	// as the request to the `MakeConnection`.
	let channel = Endpoint::try_from("http://[::]:50051")?
	.connect_with_connector(service_fn(|_: Uri| {
	let path = "/tmp/tonic/helloworld";
	// Connect to a Uds socket
	UnixStream::connect(path)
	}))
	.await?;
	let mut client = GreeterClient::new(channel);

It would be great if tonic and its hyperium dependencies, as needed, took ownership of the specified path to avoid the user needing to vend a &'static str.

Related

• Captured path perhaps eventually should be supported through a URI that supports file URLs: parse::<Uri> fails to parse uris with triple slash after scheme http#323
• Proposal to update UDS client example with a workaround: Update UDS example with socket paths determined at runtime #1611

[philjb]

I second this and am currently using Box::leak() to work around it. Some of my rust teammates helped me out: An Arc or a cloned PathBuf should also meet the 'static requirements.

like

    let path = PathBuf::from("/tmp/tonic/helloworld");

    let channel = Endpoint::try_from("http://[::]:50051")?
        .connect_with_connector(service_fn(move |_: Uri| {
            // Connect to a Uds socket
            UnixStream::connect(path.clone())
        }))
        .await?;