Ensure that logging for Azure KeyVault 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 that the user provides. This creates a new container named insights-logs-auditevent automatically for the specified storage account, and this same storage account can be used for collecting logs for multiple key vaults.

From Azure Console

1. Go to 'Key vaults'
2. For each Key vault
3. Go to 'Diagnostic settings'
4. Click on 'Edit Settings'
5. Enable 'Archive to a storage account'
6. Check 'AuditEvent'
7. Change the retention days to be 180, 0 (for indefinite) or as appropriate

Using Azure Command Line Interface 2.0

az monitor diagnostic-settings update --name "Key vault retention policy" --resource "" --set retentionPolicy.days=90
.