Determine causes of non-compliance

When an Azure resource is determined to be non-compliant to a policy rule, it's helpful to understand which portion of the rule the resource isn't compliant with. It's also useful to understand what change altered a previously compliant resource to make it non-compliant. There are two ways to find this information:

• Compliance details
• Change history (Preview)

Compliance details

When a resource is non-compliant, the compliance details for that resource are available from the Policy compliance page. The compliance details pane includes the following information:

• Resource details such as name, type, location, and resource ID
• Compliance state and timestamp of the last evaluation for the current policy assignment
• A list of reasons for the resource non-compliance

To view the compliance details, follow these steps:

1. Launch the Azure Policy service in the Azure portal by selecting All services, then searching for and selecting Policy.

2. On the Overview or Compliance page, select a policy in a compliance state that is Non-compliant.

3. Under the Resource compliance tab of the Policy compliance page, select and hold (or right-click) or select the ellipsis of a resource in a compliance state that is Non-compliant. Then select View compliance details.

   

4. The Compliance details pane displays information from the latest evaluation of the resource to the current policy assignment. In this example, the field Microsoft.Sql/servers/version is found to be 12.0 while the policy definition expected 14.0. If the resource is non-compliant for multiple reasons, each is listed on this pane.

   

   For an auditIfNotExists or deployIfNotExists policy definition, the details include the details.type property and any optional properties. For a list, see auditIfNotExists properties and deployIfNotExists properties. Last evaluated resource is a related resource from the details section of the definition.

   Example partial deployIfNotExists definition:

   {
       "if": {
           "field": "type",
           "equals": "[parameters('resourceType')]"
       },
       "then": {
           "effect": "DeployIfNotExists",
           "details": {
               "type": "Microsoft.Insights/metricAlerts",
               "existenceCondition": {
                   "field": "name",
                   "equals": "[concat(parameters('alertNamePrefix'), '-', resourcegroup().name, '-', field('name'))]"
               },
               "existenceScope": "subscription",
               "deployment": {
                   ...
               }
           }
       }
   }
   

   

These details explain why a resource is currently non-compliant, but don't show when the change was made to the resource that caused it to become non-compliant. For that information, see Change history (Preview) below.

Compliance reasons

Resource Manager modes and Resource Provider modes each have different reasons for non-compliance.

General Resource Manager mode compliance reasons

The following table maps each Resource Manager mode reason to the responsible condition in the policy definition:

AKS Resource Provider mode compliance reasons

The following table maps each Microsoft.Kubernetes.Data Resource Provider mode reason to the responsible state of the constraint template in the policy definition:

Component details for Resource Provider modes

For assignments with a Resource Provider mode, select the Non-compliant resource to open a deeper view. Under the Component Compliance tab is additional information specific to the Resource Provider mode on the assigned policy showing the Non-compliant Component and Component ID.

Compliance details for guest configuration

For policy definitions in the Guest Configuration category, there could be multiple settings evaluated inside the virtual machine and you'll need to view per-setting details. For example, if you're auditing for a list of security settings and only one of them has status Non-compliant, you'll need to know which specific settings are out of compliance and why.

You also might not have access to sign in to the virtual machine directly but you need to report on why the virtual machine is Non-compliant.

Azure portal

Begin by following the same steps in the section above for viewing policy compliance details.

In the Compliance details pane view, select the link Last evaluated resource.

The Guest Assignment page displays all available compliance details. Each row in the view represents an evaluation that was performed inside the machine. In the Reason column, a phrase is shown describing why the Guest Assignment is Non-compliant. For example, if you're auditing password policies, the Reason column would display text including the current value for each setting.

View configuration assignment details at scale

The guest configuration feature can be used outside of Azure Policy assignments. For example, Azure AutoManage creates guest configuration assignments, or you might assign configurations when you deploy machines.

To view all guest configuration assignments across your tenant, from the Azure portal open the Guest Assignments page. To view detailed compliance information, select each assignment using the link in the column "Name".

Change history (Preview)

As part of a new public preview, the last 14 days of change history are available for all Azure resources that support complete mode deletion. Change history provides details about when a change was detected and a visual diff for each change. A change detection is triggered when the Azure Resource Manager properties are added, removed, or altered.

1. Launch the Azure Policy service in the Azure portal by selecting All services, then searching for and selecting Policy.

2. On the Overview or Compliance page, select a policy in any compliance state.

3. Under the Resource compliance tab of the Policy compliance page, select a resource.

4. Select the Change History (preview) tab on the Resource Compliance page. A list of detected changes, if any exist, are displayed.

   

5. Select one of the detected changes. The visual diff for the resource is presented on the Change history page.

   

The visual diff aides in identifying changes to a resource. The changes detected may not be related to the current compliance state of the resource.

Change history data is provided by Azure Resource Graph. To query this information outside of the Azure portal, see Get resource changes.

Next steps

• Review examples at Azure Policy samples.
• Review the Azure Policy definition structure.
• Review Understanding policy effects.
• Understand how to programmatically create policies.
• Learn how to get compliance data.
• Learn how to remediate non-compliant resources.
• Review what a management group is with Organize your resources with Azure management groups.