Ensure that logging for Azure Key Vault is 'Enabled'

Description:

Enable AuditEvent logging for key vault instances to ensure interactions with key vaults are logged and available.

Rationale:

Monitoring how and when key vaults are accessed, and by whom, enables an audit trail of interactions with confidential information, keys, and certificates managed by Azure Keyvault. Enabling logging for Key Vault saves information in an Azure storage account which the user provides. This creates a new container named insights-logs-auditevent automatically for the specified storage account. This same storage account can be used for collecting logs for multiple key vaults.

From Azure Portal

1. Go to 'Key vaults'
2. Select a Key vault
3. Select 'Diagnostic settings'
4. Click on 'Edit setting' against an existing diagnostic setting, or 'Add diagnostic setting'
5. If creating a new diagnostic setting, provide a name
6. Check 'Archive to a storage account'
7. Under Categories, check 'Audit Logs'
8. Set an appropriate value for 'Retention (days)'
9. Click 'Save'

From Azure CLI

To update an existing 'Diagnostic Settings'

az monitor diagnostic-settings update --name "" --resource --set retentionPolicy.days=90

To create a new 'Diagnostic Settings'

az monitor diagnostic-settings create --name --resource --logs "[{category:AuditEvents,enabled:true,retention-policy:{enabled:true,days:180}}]" --metrics "[{category:AllMetrics,enabled:true,retention-policy:{enabled:true,days:180}}]" <[--event-hub --event-hub-rule | --storage-account |--workspace | --marketplace-partner-id ]>

From PowerShell

Create the 'Log' settings object

$logSettings = @()
$logSettings += New-AzDiagnosticSettingLogSettingsObject -Enabled $true -RetentionPolicyDay 180 -RetentionPolicyEnabled $true -Category AuditEvent

Create the 'Metric' settings object

$metricSettings = @()
$metricSettings += New-AzDiagnosticSettingMetricSettingsObject -Enabled $true -RetentionPolicyDay 180 -RetentionPolicyEnabled $true -Category AllMetrics

Create the 'Diagnostic Settings' for each 'Key Vault'

New-AzDiagnosticSetting -Name "" -ResourceId -Log $logSettings -Metric $metricSettings [-StorageAccountId | -EventHubName -EventHubAuthorizationRuleId | -WorkSpaceId | -MarketPlacePartnerId ]