add log analytics workspace to enable logging on IoT Hub

infra/main.bicep

@@ -35,6 +35,9 @@ param cosmosDbName string = '${prefix}cosmosdb'
 @description('Specifies the name of the Azure IoT Hub resource.')
 param iotHubName string = '${prefix}iothub'
 
+@description('Specifies the name of the Azure Log Analytics workspace.')
+param logAnalyticsWorkspaceName string = '${prefix}law'
+
 module openAi './modules/openAi.bicep' = {
   name: 'openAi'
   params: {
@@ -101,6 +104,16 @@ module iotHub './modules/iotHub.bicep' = {
     name: iotHubName
     location: location
     tags: tags
+    workspaceId: logAnalytics.outputs.id
+  }
+}
+
+module logAnalytics './modules/logAnalytics.bicep' = {
+  name: 'logAnalytics'
+  params: {
+    name: logAnalyticsWorkspaceName
+    location: location
+    tags: tags
   }
 }
 

infra/modules/iotHub.bicep

@@ -17,6 +17,9 @@ param skuName string = 'S1'
 @description('The number of IoT Hub units.')
 param skuUnits int = 1
 
+@description('Specifies the resource id of the Log Analytics workspace.')
+param workspaceId string
+
 resource iotHub 'Microsoft.Devices/IotHubs@2023-06-30' = {
   name: name
   location: location
@@ -27,6 +30,27 @@ resource iotHub 'Microsoft.Devices/IotHubs@2023-06-30' = {
   }
 }
 
+resource diagnosticSettings 'Microsoft.Insights/diagnosticSettings@2021-05-01-preview' = {
+  name: 'diagnosticSettings'
+  scope: iotHub
+  properties: {
+    workspaceId: workspaceId
+    metrics: [
+      for metric in ['AllMetrics']: {
+        category: metric
+        enabled: true
+        timeGrain: null
+      }
+    ]
+    logs: [
+      for categoryGroup in ['allLogs', 'audit']: {
+        categoryGroup: categoryGroup
+        enabled: true
+      }
+    ]
+  }
+}
+
 // Outputs
 output iotHubId string = iotHub.id
 output iotHubName string = iotHub.name

infra/modules/logAnalytics.bicep

@@ -0,0 +1,39 @@
+// Parameters
+@description('Specifies the name of the Log Analytics workspace.')
+param name string
+
+@description('Specifies the service tier of the workspace: Free, Standalone, PerNode, Per-GB.')
+@allowed([
+  'Free'
+  'Standalone'
+  'PerNode'
+  'PerGB2018'
+])
+param sku string = 'PerGB2018'
+
+@description('Specifies the workspace data retention in days. -1 means Unlimited retention for the Unlimited Sku. 730 days is the maximum allowed for all other Skus.')
+param retentionInDays int = 60
+
+@description('Specifies the location.')
+param location string = resourceGroup().location
+
+@description('Specifies the resource tags.')
+param tags object
+
+// Resources
+resource logAnalyticsWorkspace 'Microsoft.OperationalInsights/workspaces@2023-09-01' = {
+  name: name
+  tags: tags
+  location: location
+  properties: {
+    sku: {
+      name: sku
+    }
+    retentionInDays: retentionInDays
+  }
+}
+
+//Outputs
+output id string = logAnalyticsWorkspace.id
+output name string = logAnalyticsWorkspace.name
+output customerId string = logAnalyticsWorkspace.properties.customerId