How to enable diagnostics with bicep for Azure Web PubSub?

Question

The Azure WebPub bicep documentation mentions nothing about how to enable diagnostic settings to stream logs to a log analytics workspace, but the Azure Portal has an interface for it.

https://learn.microsoft.com/en-us/azure/templates/microsoft.signalrservice/2021-10-01/webpubsub?pivots=deployment-language-bicep

I am guessing that I have to create a Microsoft.Insights/diagnosticSettings resource, buy the same thing applies here. No apparent documentation.

How do I enable diagnostics with bicep for Azure Web PubSub?

Answer 1

Thanks for getting me in the right direction @Thomas. Your category names were a bit off and I also needed a workspaceId in the properties. After many attempts I got the category names by simply exporting my manual configuration to ARM and saw that the names should be as below.

resource webPubSubDiagnosticSettings 'Microsoft.Insights/diagnosticSettings@2021-05-01-preview' = {
  name: '${webPubSubName}-DiagnosticSettings' 
  scope: webpubsub
  properties: {
    workspaceId: logAnalyticsWorkspace.id
    logs: [
      {
        category: 'ConnectivityLogs'
        enabled: true
      }
      {
        category: 'MessagingLogs'
        enabled: true
      }
      {
        category: 'HttpRequestLogs'
        enabled: true
      }
    ]
    metrics: [
      {
        enabled: true
        category: 'AllMetrics'
      }
    ]
  }
}

Answer 2

Something like that should work:

param webPubSubName string

// Get a reference to the existing signalR service
resource signalR 'Microsoft.SignalRService/webPubSub@2021-10-01' existing = {
  name:webPubSubName
}

// Get the log category to send
// See https://learn.microsoft.com/en-us/azure/azure-monitor/reference/tables/tables-resourcetype?source=recommendations#signalr-service-webpubsub
var logTypes = [
  'AzureActivity'
  'WebPubSubConnectivity'
  'WebPubSubHttpRequest'
  'WebPubSubMessaging'
]

// Send logs to azure monitor
resource webPubSubLogs 'Microsoft.Insights/diagnosticSettings@2021-05-01-preview' = {
  scope: signalR
  name: signalR.name
  properties: {
    ...
    logs: [for logType in logTypes: {
      category: logType
      enabled: true
      retentionPolicy: {
        enabled: true
        days: 0
      }
    }]
    metrics: [
      {
        category: 'AllMetrics'
        enabled: true
        retentionPolicy: {
          enabled: true
          days: 0
        }
      }
    ]
  }
}