Tutorial: Create a policy assignment to identify non-compliant resources

The first step in understanding compliance in Azure is to identify the status of your resources. Azure Policy supports auditing the state of your Azure Arc-enabled server with guest configuration policies. Azure Policy's guest configuration definitions can audit or apply settings inside the machine. This tutorial steps you through the process of creating and assigning a policy, identifying which of your Azure Arc-enabled servers don't have the Log Analytics agent installed.

At the end of this process, you'll successfully identify machines that don't have the Log Analytics agent for Windows or Linux installed. They're non-compliant with the policy assignment.

Prerequisites

If you don't have an Azure subscription, create a free account before you begin.

Create a policy assignment

In this tutorial, you create a policy assignment and assign the [Preview]: Log Analytics agent should be installed on your Linux Azure Arc machines policy definition.

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

    Search for Policy in All Services

  2. Select Assignments on the left side of the Azure Policy page. An assignment is a policy that has been assigned to take place within a specific scope.

    Select Assignments page from Policy Overview page

  3. Select Assign Policy from the top of the Policy - Assignments page.

    Assign a policy definition from Assignments page

  4. On the Assign Policy page, select the Scope by clicking the ellipsis and selecting either a management group or subscription. Optionally, select a resource group. A scope determines what resources or grouping of resources the policy assignment gets enforced on. Then click Select at the bottom of the Scope page.

    This example uses the Parnell Aerospace subscription. Your subscription will differ.

  5. Resources can be excluded based on the Scope. Exclusions start at one level lower than the level of the Scope. Exclusions are optional, so leave it blank for now.

  6. Select the Policy definition ellipsis to open the list of available definitions. Azure Policy comes with built-in policy definitions you can use. Many are available, such as:

    • Enforce tag and its value
    • Apply tag and its value
    • Inherit a tag from the resource group if missing

    For a partial list of available built-in policies, see Azure Policy samples.

  7. Search through the policy definitions list to find the [Preview]: Log Analytics agent should be installed on your Windows Azure Arc machines definition if you have enabled the Arc-enabled servers agent on a Windows-based machine. For a Linux-based machine, find the corresponding [Preview]: Log Analytics agent should be installed on your Linux Azure Arc machines policy definition. Click on that policy and click Select.

    Find the correct policy definition

  8. The Assignment name is automatically populated with the policy name you selected, but you can change it. For this example, leave [Preview]: Log Analytics agent should be installed on your Windows Azure Arc machines or [Preview]: Log Analytics agent should be installed on your Linux Azure Arc machines depending on which one you selected. You can also add an optional Description. The description provides details about this policy assignment. Assigned by will automatically fill based on who is logged in. This field is optional, so custom values can be entered.

  9. Leave Create a Managed Identity unchecked. This box must be checked when the policy or initiative includes a policy with the deployIfNotExists effect. As the policy used for this quickstart doesn't, leave it blank. For more information, see managed identities and how remediation security works.

  10. Click Assign.

You're now ready to identify non-compliant resources to understand the compliance state of your environment.

Identify non-compliant resources

Select Compliance in the left side of the page. Then locate the [Preview]: Log Analytics agent should be installed on your Windows Azure Arc machines or [Preview]: Log Analytics agent should be installed on your Linux Azure Arc machines policy assignment you created.

Compliance details on the Policy Compliance page

If there are any existing resources that aren't compliant with this new assignment, they appear under Non-compliant resources.

When a condition is evaluated against your existing resources and found true, then those resources are marked as non-compliant with the policy. The following table shows how different policy effects work with the condition evaluation for the resulting compliance state. Although you don't see the evaluation logic in the Azure portal, the compliance state results are shown. The compliance state result is either compliant or non-compliant.

Resource State Effect Policy Evaluation Compliance State
Exists Deny, Audit, Append*, DeployIfNotExist*, AuditIfNotExist* True Non-Compliant
Exists Deny, Audit, Append*, DeployIfNotExist*, AuditIfNotExist* False Compliant
New Audit, AuditIfNotExist* True Non-Compliant
New Audit, AuditIfNotExist* False Compliant

* The Append, DeployIfNotExist, and AuditIfNotExist effects require the IF statement to be TRUE. The effects also require the existence condition to be FALSE to be non-compliant. When TRUE, the IF condition triggers evaluation of the existence condition for the related resources.

Clean up resources

To remove the assignment created, follow these steps:

  1. Select Compliance (or Assignments) in the left side of the Azure Policy page and locate the [Preview]: Log Analytics agent should be installed on your Windows Azure Arc machines or [Preview]: Log Analytics agent should be installed on your Linux Azure Arc machines policy assignment you created.

  2. Right-click the policy assignment and select Delete assignment.

    Delete an assignment from the Compliance page

Next steps

In this tutorial, you assigned a policy definition to a scope and evaluated its compliance report. The policy definition validates that all the resources in the scope are compliant and identifies which ones aren't. Now you are ready to monitor your Azure Arc-enabled servers machine by enabling VM insights.

To learn how to monitor and view the performance, running process and their dependencies from your machine, continue to the tutorial: