AddStackExchangeRedis doesn't read Aspire connection string

[dart1235]

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

I'm using AddStackExchangeRedis() method to setup SignalR's Redis backplane. However, the API service can't connect to the Redis instance.

Here's the code from AppHost's Program.cs

var builder = DistributedApplication.CreateBuilder(args);
var redis = builder.AddRedis("redis-cache");
builder.AddProject<Projects.BlazorSingalRApp1>("blazorsingalrapp1")
    .WithReference(redis);

builder.Build().Run();

And here's how the API service (BlazorSingalRApp1) project's program.cs is configured

builder.Services.AddSignalR()
    .AddStackExchangeRedis("redis-cache", options =>
    {
        options.Configuration.ChannelPrefix = "MyApp";
        options.Configuration.AbortOnConnectFail = false;
    });

However, when I run the apphost, the backend API service can't connect and the logs show

fail: Microsoft.AspNetCore.SignalR.StackExchangeRedis.RedisHubLifetimeManager[7] Not connected to Redis.
StackExchange.Redis.RedisConnectionException: UnableToConnect on redis-cache:6379/Subscription

It appears that maybe AddStackExchangeRedis call doesn't honor the connection string coming from Aspire because at runtime config.GetConnectionString("redis-cache") has the right connection string.

Expected Behavior

No response

Steps To Reproduce

No response

Exceptions (if any)

No response

.NET Version info

9.0

Anything else?

Aspire 9.3.1

[davidfowl]

This is a SignalR issue.

cc @BrennanConroy

[dart1235]

As a workaround, I did this:

var redisConnectionString = builder.Configuration.GetConnectionString("redis-cache")!;
builder.Services.AddSignalR()
    .AddStackExchangeRedis(redisConnectionString, options =>
    {
        //options.Configuration.
        // Optional: set configuration options
        options.Configuration.ChannelPrefix = RedisChannel.Literal("MyApp");
        options.Configuration.AbortOnConnectFail = false;
    });

[davidfowl]

That;s the right fix. Transfering this to SignalR

[BrennanConroy]

The problem with the current overload is that the parameter is named connectionString. It'd be a bit weird if we made it try to grab a connection string from DI using the value.

Looks like ASRS had a similar API and added a new overload for a named connection string:
AddNamedAzureSignalR(string name).