services.AddSignalR().AddAzureSignalR("<connection_string>"); connection string not working in Azure Function Dotnet isolated process as mentioned in MS Document for SignalR

[Shandilyavivek-lab]

Description

As mentioned in MS Document using the code in Program.cs file throws exception

Exceptions (if any)

error image

To Reproduce

Function.cs

using System.Collections.Generic;
using System.Net;
using Microsoft.AspNetCore.Mvc.ModelBinding.Binders;
using Microsoft.Azure.Functions.Worker;
using Microsoft.Azure.Functions.Worker.Http;
using Microsoft.Extensions.Logging;

namespace FunctionApp7
{
    public class Function
    {
        private readonly ILogger _logger;

        public Function(ILoggerFactory loggerFactory)
        {
            _logger = loggerFactory.CreateLogger("negotiate");

        }

        [Function("negotiate")]
        public async Task<HttpResponseData> Negotiate(
            [HttpTrigger(AuthorizationLevel.Anonymous, "post")] HttpRequestData req,
            [SignalRConnectionInfoInput(HubName = "serverless")] MyConnectionInfo connectionInfo)
        {
            _logger.LogInformation($"SignalR Connection URL = '{connectionInfo.Url}'");
            var response = req.CreateResponse(HttpStatusCode.OK);
            response.Headers.Add("Content-Type", "text/plain; charset=utf-8");
            response.WriteStringAsync($"Connection URL = '{connectionInfo.Url}'");

            return response;
        }
    }

    public class MyConnectionInfo
    {
        public string Url { get; set; }

        public string AccessToken { get; set; }
    }
}

Program.cs

using Microsoft.Azure.Functions.Worker;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;
using static System.Net.WebRequestMethods;


var host = new HostBuilder()
    .ConfigureFunctionsWebApplication()
    .ConfigureServices(services =>
    {
        services.AddApplicationInsightsTelemetryWorkerService();
        services.ConfigureFunctionsApplicationInsights();
        services.AddSignalR().AddAzureSignalR("Endpoint = https://xxxxxxxxxservice.signalr.net;AccessKey=VndLYg4tI1xxxxxxxxxxxxxxxxxx=;Version=1.0;");
            })
    .ConfigureLogging(logging =>
    {
        logging.Services.Configure<LoggerFilterOptions>(options =>
        {
            LoggerFilterRule defaultRule = options.Rules.FirstOrDefault(rule => rule.ProviderName
                == "Microsoft.Extensions.Logging.ApplicationInsights.ApplicationInsightsLoggerProvider");
            if (defaultRule is not null)
            {
                options.Rules.Remove(defaultRule);
            }
        });
    })
    .Build();

host.Run();

Csproj

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <TargetFramework>net8.0</TargetFramework>
    <AzureFunctionsVersion>v4</AzureFunctionsVersion>
    <OutputType>Exe</OutputType>
    <ImplicitUsings>enable</ImplicitUsings>
    <Nullable>enable</Nullable>
  </PropertyGroup>
  <ItemGroup>
    <FrameworkReference Include="Microsoft.AspNetCore.App" />
    <PackageReference Include="Microsoft.Azure.Functions.Worker" Version="1.20.1" />
    <PackageReference Include="Microsoft.Azure.Functions.Worker.Extensions.Http" Version="3.1.0" />
    <PackageReference Include="Microsoft.Azure.Functions.Worker.Extensions.Http.AspNetCore" Version="1.2.0" />
    <PackageReference Include="Microsoft.Azure.Functions.Worker.Extensions.SignalRService" Version="1.13.0" />
    <PackageReference Include="Microsoft.Azure.Functions.Worker.Extensions.Timer" Version="4.1.0" />
    <PackageReference Include="Microsoft.Azure.Functions.Worker.Sdk" Version="1.16.4" />
    <PackageReference Include="Microsoft.ApplicationInsights.WorkerService" Version="2.21.0" />
    <PackageReference Include="Microsoft.Azure.Functions.Worker.ApplicationInsights" Version="1.1.0" />
  </ItemGroup>
  <ItemGroup>
    <None Update="host.json">
      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
    </None>
    <None Update="local.settings.json">
      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
      <CopyToPublishDirectory>Never</CopyToPublishDirectory>
    </None>
  </ItemGroup>
  <ItemGroup>
    <Using Include="System.Threading.ExecutionContext" Alias="ExecutionContext" />
  </ItemGroup>
</Project>

If i use connectionstring in local setting it works perfectly fine. But as mentioned document it should also work fine

[Y-Sindo]

services.AddSignalR().AddAzureSignalR() uses Azure SignalR Service in default mode, which is not working for Azure Functions. To use Azure SignalR in Azure Functions, you should use serverless mode. Will improve the document to point out that.

FYI: Service mode in Azure SignalR Service