fix(client): if tonic has tls feature

[fcfangcc]

fixed #261

In tonic, if uri startwith "https", will use tls connect.

https://github.com/hyperium/tonic/blob/eeb3268f71ae5d1107c937392389db63d8f721fb/tonic/src/transport/service/connector.rs#L74-L90

Just change uri prefix "http" can skip this logic.Like:
https://github.com/hyperium/tonic/blob/eeb3268f71ae5d1107c937392389db63d8f721fb/examples/src/uds/client.rs#L19

[jsturtevant]

are there some scenarios where we would want https?

[mxpv]

tonic::transport::Error(Transport, hyper::Error(Connect, HttpsUriWithoutTlsSupport(())))

Possibly we could enable a missing feature in Tonic instead?

[fcfangcc]

The https://[::] is disabled here, you can any str replace https.(Except https and tls feature enable)

Connect will replace connect_with_connector function with xx.sock .

Style of writing because Tonic channel only build with Endpoint

[jsturtevant]

Ok, I think I see now, the comment right above links to a sample that states:

// 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`.

Endpoint parses as URI but the domain socket isn't a uri so we move on and connect to the with our client. The uri that was initially passed is ignored in statement below tower::service_fn(move |_<this is the uri>| {

When the value is https and tls feature is enabled (as it is) it executes this code on that temp value: https://github.com/hyperium/tonic/blob/eeb3268f71ae5d1107c937392389db63d8f721fb/tonic/src/transport/service/connector.rs#L80-L91

We could essentially change this string to anything we want that parses as an "endpoint" (Uri) like unix://unused since it isn't used.

We could also be more explicit and append file::// to the path like:

let channel = Endpoint::try_from("file://var/run/containerd/containerd.sock")
        .unwrap()
        .connect_with_connector(tower::service_fn(move |uri: tonic::transport::Uri| {
            let p = uri.path().to_owned();
            UnixStream::connect(p)
        }))
        .await?;

[mxpv]

oh, sorry, now I get it too :)
I think it deserves a comment.

[jsturtevant]

LGTM, @fcfangcc could you add a comment explaining what is happening?

[fcfangcc]

@jsturtevant You mean to add a comment explaining in the source code?

[jsturtevant]

Yes, essentially describing a summary of #264 (comment). We had to dive in and dig around to figure out what was going on. It would be nice to leave a quick explanation for the next person to point out what seems like a strange set up (setting up with http/https but actually ignoring that value all together and using our own logic to connect).