audit_log_analytics_workspace_retention.json

{
  "type": "Microsoft.Authorization/policyDefinitions",
  "name": "audit_log_analytics_workspace_retention",
  "properties": {
    "metadata": {
      "category": "Monitoring"
    },
    "parameters": {
      "effect": {
        "type": "String",
        "metadata": {
          "displayName": "Effect",
          "description": "Enable or disable the execution of the policy"
        },
        "allowedValues": [
          "AuditIfNotExists",
          "Disabled"
        ],
        "defaultValue": "AuditIfNotExists"
      },
      "workspaceRetentionDays": {
        "type": "Integer",
        "metadata": {
          "description": "Log Analytics Workspace should be retained for the specified amount of days. Defaults to 15 months",
          "displayName": "Log Analytics Workspace Retention Days"
        },
        "defaultValue": 456
      }
    },
    "policyRule": {
      "if": {
        "allOf": [
          {
            "field": "type",
            "equals": "Microsoft.OperationalInsights/workspaces"
          }
        ]
      },
      "then": {
        "effect": "[parameters('effect')]",
        "details": {
          "type": "Microsoft.OperationalInsights/workspaces",
          "existenceCondition": {
            "field": "Microsoft.OperationalInsights/workspaces/retentionInDays",
            "greaterOrEquals": "[parameters('workspaceRetentionDays')]"
          }
        }
      }
    }
  }
}