Azure 中托管的 Blazor 应用未连接到 Azure SignalR 实例

Question

We have a Blazor application hosted as an Azure Web App that doesn't seem to connect to the Azure SignalR instance, and instead creates a WebSocket connection to the Web App itself. But when running the app locally, it correctly connects to the SignalR instance.

On the Azure web app:

Running locally:

For running locally, we have the connection string stored as a User Secret:

"Azure:SignalR:ConnectionString": "Endpoint=https://<HOST>.service.signalr.net;AccessKey=<KEY>;Version=1.0;"

And for Azure, we have a configuration setting:

In code, we have:

builder.Services.AddServerSideBlazor();
....
app.MapBlazorHub();

What could be preventing the Azure app from using the SignalR service?

UPDATE

Interestingly, when we publish manually from within Visual Studio, adding SignalR as a service dependency, it works correctly. However, when deploying via our CI server (Azure DevOps) it reverts back to not using the SignalR service.

We have looked at the app config in Azure and cannot see any differences - but it looks like something gets set when deploying manually from VS that doesn't get set when deploying from DevOps. The deployment task looks like this:

  - task: AzureRmWebAppDeployment@4
    displayName: 'Deploy to Azure App Service'
    condition: eq('${{ parameters.slot }}', '')
    inputs:
      ConnectionType: 'AzureRM'
      azureSubscription: '<SubName>'
      appType: 'webApp'
      WebAppName: '<AppName>'
      ResourceGroupName: '<RG>'
      packageForLinux: '$(System.ArtifactsDirectory)/drop/<App>.zip'   

Answer 1

Did you activate WebSocket on your Azure Web App?