Connecting to gRPC Server over Unix Domain Socket
- Dominant language
- C#
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Description
Following the [example](https://learn.microsoft.com/en-us/aspnet/core/grpc/interprocess-uds?view=aspnetcore-8.0) in the docs, I tried to connect to a gRPC server listening on a Unix Domain Socket. I created a small program to test it
```
using System.Net;
using System.Net.Sockets;
using Grpc.Net.Client;
var socketPath = "/tmp/foo.sock";
var udsEndPoint = new UnixDomainSocketEndPoint(socketPath);
var connectionFactory = new UnixDomainSocketsConnectionFactory(udsEndPoint);
var socketsHttpHandler = new SocketsHttpHandler
{
ConnectCallback = connectionFactory.ConnectAsync
};
var grpc = GrpcChannel.ForAddress("http://localhost", new GrpcChannelOptions
{
HttpHandler = socketsHttpHandler
});
await grpc.ConnectAsync();
public class UnixDomainSocketsConnectionFactory
{
private readonly EndPoint endPoint;
public UnixDomainSocketsConnectionFactory(EndPoint endPoint)
{
this.endPoint = endPoint;
}
public async ValueTask ConnectAsync(SocketsHttpConnectionContext _,
CancellationToken cancellationToken = default)
{
var socket = new Socket(AddressFamily.Unix, SocketType.Stream, ProtocolType.Unspecified);
try
{
await socket.ConnectAsync(this.endPoint, cancellationToken).ConfigureAwait(false);
return new NetworkStream(socket, true);
}
catch
{
socket.Dispose();
throw;
}
}
}
```
However, I am getting the following error:
```
Unhandled exception. System.InvalidOperationException: Channel is configured with an HTTP transport doesn't support client-side load balancing or connectivity state tracking. The underlying HTTP transport must be a SocketsHttpHandler with no SocketsHttpHandler.ConnectCallback configured. The HTTP transport must be configured on the channel using GrpcChannelOptions.HttpHandler.
at Grpc.Net.Client.GrpcChannel.ValidateHttpHandlerSupportsConnectivity()
at Grpc.Net.Client.GrpcChannel.ConnectAsync(CancellationToken cancellationToken)
at Program.$(String[] args) in /mnt/d/Dropbox/dev/GitHub/viam-dotnet-sdk/examples/ConsoleApp1/Program.cs:line 20
at Program.(String[] args)
Aborted
```
I'm guessing this behavior changed since 1-Jan-2024, but not sure what the solution is here.
Contributor guide
Research direction
Start with the linked Unix Domain Socket documentation example and the GrpcChannel.ConnectAsync call at Program.cs line 20. Trace GrpcChannel.ValidateHttpHandlerSupportsConnectivity and compare its requirements with the configured SocketsHttpHandler. Done means the supported configuration or required documentation change is clearly established and verified against the reported exception.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- csharp, grpc
- Domain
- backend-api-design
- Issue type
- Bug
- Difficulty
- 3/5
- Estimated time
- 1-2 days
- Activity status
- Stale
- Clarity
- Needs clarification
- Newbie friendliness
- 35/100