Adding Ocelot to web API breaks SignalR - asp.net-core

Question

I have a web API project where I use SignalR. Recently I added and configured Ocelot to be my gateway towards another web API. Ocelot routes the requests correctly but has messed up my SignalR configuration somehow.
Program.cs:
builder.Services.AddOcelot();
var app = builder.Build();
app.UseCors("AllowAllApps");
JwtSecurityTokenHandler.DefaultInboundClaimTypeMap.Clear();
app.UseAuthentication();
app.UseAuthorization();
app.UseMvc();
app.UseOcelot().Wait();
app.MapHub<MyHub>("/myHub");
app.Run();
Client-side code:
// url = "http://localhost:5001/myHub"
connect(url: string, accessToken: string, debug: boolean): Promise<void> {
this.connection = new signalR.HubConnectionBuilder()
.withUrl(url, { accessTokenFactory: () => accessToken })
.configureLogging(debug ? signalR.LogLevel.Information : signalR.LogLevel.Error)
.withAutomaticReconnect()
.build();
return this.connection.start();
}
Ocelot.json
{
"Routes": [
{
"DownstreamPathTemplate": "/{route}",
"DownstreamScheme": "http",
"DownstreamHostAndPorts": [
{
"Host": "myotherapi",
"Port": 80
}
],
"UpstreamPathTemplate": "/myotherapi/{route}",
"UpstreamHttpMethod": [ "Post" ],
"AuthenticationOptions": {
"AuthenticationProviderKey": "Bearer",
"AllowedScopes": []
},
"AddHeadersToRequest": {
"UserId": "Claims[sub] > value"
}
}
],
"GlobalConfiguration": {
"BaseUrl": "http://localhost:5001"
}
}
I need Ocelot only for HTTP requests. It shouldn't affect websocket connections with this configuration as far as I understand.
If I comment out the Ocelot lines in my Program.cs SignalR works. If I leave it there my POST request to http://localhost:5001/myHub/negotiate?negotiateVersion=1 fails with 404.
Is it something to do with the order of the middleware that is causing the issue? I have tried multiple different orderings but to no avail.
This is a .NET 6 project with Ocelot version 18.0. Both projects are containerized with Docker.

Answer 1

try adding this
{
"DownstreamPathTemplate": "/myHub/negotiate",
"DownstreamScheme": "http",
"DownstreamHostAndPorts": [
{
"Host": "myotherapi",
"Port": "80"
}
],
"UpstreamPathTemplate": "/myHub/negotiate",
"UpstreamHttpMethod": [ "POST" ]
}