refactor(tvix/castore/tonic): make async, support wait-connect=? r/7022

This moves the sync `channel::from_url` to a async
`tonic::channel_from_url`. It now allows connecting non-lazily if `wait-
connect=1` is set in the URL params.

Also, make the pingpong tests for blobsvc and directorysvc use the wait-
connect=1 codepath.

Change-Id: Ibeea33117c8121814627e7f6aba0e943ae2e92ca
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10030
Tested-by: BuildkiteCI
Reviewed-by: Connor Brewster <cbrewster@hey.com>

1 files changed, 0 insertions, 128 deletions

diff --git a/tvix/castore/src/channel.rs b/tvix/castore/src/channel.rs
deleted file mode 100644
index 2fe97247679a..000000000000
--- a/tvix/castore/src/channel.rs
+++ /dev/null
@@ -1,128 +0,0 @@
-use tokio::net::UnixStream;
-use tonic::transport::Channel;
-
-/// Turn a [url::Url] to a [Channel] if it can be parsed successfully.
-/// It supports `grpc+unix:/path/to/socket`,
-/// as well as the regular schemes supported by tonic, prefixed with grpc+,
-/// for example `grpc+http://[::1]:8000`.
-pub fn from_url(url: &url::Url) -> Result<Channel, self::Error> {
-    // Start checking for the scheme to start with grpc+.
-    // If it doesn't start with that, bail out.
-    match url.scheme().strip_prefix("grpc+") {
-        None => Err(Error::MissingGRPCPrefix()),
-        Some(rest) => {
-            if rest == "unix" {
-                if url.host_str().is_some() {
-                    return Err(Error::HostSetForUnixSocket());
-                }
-
-                let url = url.clone();
-                Ok(
-                    tonic::transport::Endpoint::from_static("http://[::]:50051") // doesn't matter
-                        .connect_with_connector_lazy(tower::service_fn(
-                            move |_: tonic::transport::Uri| {
-                                UnixStream::connect(url.path().to_string().clone())
-                            },
-                        )),
-                )
-            } else {
-                // ensure path is empty, not supported with gRPC.
-                if !url.path().is_empty() {
-                    return Err(Error::PathMayNotBeSet());
-                }
-
-                // Stringify the URL and remove the grpc+ prefix.
-                // We can't use `url.set_scheme(rest)`, as it disallows
-                // setting something http(s) that previously wasn't.
-                let url = url.to_string().strip_prefix("grpc+").unwrap().to_owned();
-
-                // Use the regular tonic transport::Endpoint logic to
-                Ok(tonic::transport::Endpoint::try_from(url)
-                    .unwrap()
-                    .connect_lazy())
-            }
-        }
-    }
-}
-
-/// Errors occuring when trying to connect to a backend
-#[derive(Debug, thiserror::Error)]
-pub enum Error {
-    #[error("grpc+ prefix is missing from Url")]
-    MissingGRPCPrefix(),
-
-    #[error("host may not be set for unix domain sockets")]
-    HostSetForUnixSocket(),
-
-    #[error("path may not be set")]
-    PathMayNotBeSet(),
-
-    #[error("transport error: {0}")]
-    TransportError(tonic::transport::Error),
-}
-
-impl From<tonic::transport::Error> for Error {
-    fn from(value: tonic::transport::Error) -> Self {
-        Self::TransportError(value)
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::from_url;
-
-    /// This uses the correct scheme for a unix socket.
-    /// The fact that /path/to/somewhere doesn't exist yet is no problem, because we connect lazily.
-    #[tokio::test]
-    async fn test_valid_unix_path() {
-        let url = url::Url::parse("grpc+unix:///path/to/somewhere").expect("must parse");
-
-        assert!(from_url(&url).is_ok())
-    }
-
-    /// This uses the correct scheme for a unix socket,
-    /// but sets a host, which is unsupported.
-    #[tokio::test]
-    async fn test_invalid_unix_path_with_domain() {
-        let url =
-            url::Url::parse("grpc+unix://host.example/path/to/somewhere").expect("must parse");
-
-        assert!(from_url(&url).is_err())
-    }
-
-    /// This uses the wrong scheme
-    #[test]
-    fn test_invalid_scheme() {
-        let url = url::Url::parse("http://foo.example/test").expect("must parse");
-
-        assert!(from_url(&url).is_err());
-    }
-
-    /// This uses the correct scheme for a HTTP server.
-    /// The fact that nothing is listening there is no problem, because we connect lazily.
-    #[tokio::test]
-    async fn test_valid_http() {
-        let url = url::Url::parse("grpc+http://localhost").expect("must parse");
-
-        assert!(from_url(&url).is_ok());
-    }
-
-    /// This uses the correct scheme for a HTTPS server.
-    /// The fact that nothing is listening there is no problem, because we connect lazily.
-    #[tokio::test]
-    async fn test_valid_https() {
-        let url = url::Url::parse("grpc+https://localhost").expect("must parse");
-
-        assert!(from_url(&url).is_ok());
-    }
-
-    /// This uses the correct scheme, but also specifies
-    /// an additional path, which is not supported for gRPC.
-    /// The fact that nothing is listening there is no problem, because we connect lazily.
-    #[tokio::test]
-    async fn test_invalid_http_with_path() {
-        let url = url::Url::parse("grpc+https://localhost/some-path").expect("must parse");
-
-        assert!(from_url(&url).is_err());
-    }
-}