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SignalR Service

Add real-time messaging to clients with Azure SignalR Service bindings in PowerShell.

Negotiate Function

Clients first call a negotiate endpoint to obtain connection info. Use the signalRConnectionInfo input binding:

function.json:

{
  "bindings": [
    {
      "name": "Request",
      "type": "httpTrigger",
      "direction": "in",
      "methods": ["post"]
    },
    {
      "name": "Response",
      "type": "http",
      "direction": "out"
    },
    {
      "name": "ConnectionInfo",
      "type": "signalRConnectionInfo",
      "direction": "in",
      "hubName": "notifications",
      "connectionStringSetting": "AzureSignalRConnectionString"
    }
  ]
}

run.ps1:

param($Request, $ConnectionInfo, $TriggerMetadata)

Push-OutputBinding -Name Response -Value ([HttpResponseContext]@{
    StatusCode = [System.Net.HttpStatusCode]::OK
    Body       = ($ConnectionInfo | ConvertTo-Json)
})

Broadcasting Messages

Use the signalR output binding to push messages to connected clients:

{
  "name": "SignalRMessages",
  "type": "signalR",
  "direction": "out",
  "hubName": "notifications",
  "connectionStringSetting": "AzureSignalRConnectionString"
}

Push-OutputBinding -Name SignalRMessages -Value @{
    target    = "newMessage"
    arguments = @( @{ text = "Order shipped"; timestamp = (Get-Date).ToString("o") } )
}

Set userId on the message to target a single user, or groupName to target a group.

Serverless mode

Configure the SignalR Service instance in Serverless mode so it works with Azure Functions rather than a self-hosted hub.

See Also

Sources