Policy as Code for Services

Learn how to create and enforce OPA policies on Harness services.

Harness provides governance using Open Policy Agent (OPA), Policy Management, and Rego policies.

You can create a policy and apply it to all services in your Account, Org, or Project. The policy is evaluated on service-level events:

• On Save — evaluated when a service is created or updated.

• On Run — evaluated when a pipeline that references the service is executed.

For more details, see the Harness Governance Quickstart.

Prerequisites

• Harness Governance Overview

• Harness Governance Quickstart

• Policies use the OPA authoring language Rego. For more information, see OPA Policy Authoring.

Step 1: Add a policy

1. In Harness, go to Account Settings → Policies → New Policy.

2. Enter a Name for your policy and click Apply.

3. Add your Rego policy in the editor.

   You can write your own Rego policy or use a sample from the Library panel. Select the Library tab, choose Entity: Service from the dropdown, and pick one of the built-in samples:

   

   Service sample policies in the Library panel

   Harness ships two sample policies for services:

   • Service – Block name with prefix and deployment type: Ensures a service name contains a required prefix and uses an allowed deployment type.

   • Service – Block manifest store type: Prevents services from using a specific manifest store type (for example, GitHub).

   Below are example Rego policies you can use as a starting point.

Block services by deployment type or name prefix

package service

deny[msg] {
  input.serviceEntity.serviceDefinition.type == "Kubernetes"
  msg := "Service with Kubernetes deployment type is not allowed"
}

deny[msg] {
  startswith(input.serviceEntity.name, "BLOCKED_SERVICE_NAME")
  msg := "Service which starts with BLOCKED_SERVICE_NAME prefix is not allowed"
}

Block services that use a forbidden manifest store type

package service

deny[msg] {
  input.serviceEntity.serviceDefinition.spec.manifests[0].manifest.spec.store.type == "Github"
  msg := "Service with Github store type is not allowed for manifest"
}

1. Click Save.

Step 2: Add the policy to a policy set

After creating your policy, add it to a Policy Set before it can be enforced on services.

1. Go to Policies → Policy Sets → New Policy Set.

2. Enter a Name and optional Description for the Policy Set.

3. In Entity type, select Service.

4. In On what event should the Policy Set be evaluated, select On Save, On Run, or both depending on when you want the policy enforced.

   • On Save — the policy is evaluated every time a user creates or updates the service.

   • On Run — the policy is evaluated when a pipeline that uses the service is executed.

5. Click Continue.

   Existing services are not automatically evaluated against new policies. Policies are applied only when a service is saved (created or updated) or when a pipeline referencing the service is run.

6. In Policy evaluation criteria, click Add Policy.

7. In the Select Policy dialog, choose the scope (Project, Org, or Account) and select the policy you created.

   

   Select a policy for the policy set
8. Select the severity and action for policy violations:

   • Warn & continue — a warning is displayed if the policy is not met, but the service is saved and you can proceed.

   • Error and exit — an error is displayed and the service is not saved if the policy is not met.

9. Click Apply, then click Finish.

10. The Policy Set is automatically set to Enforced. To disable enforcement, toggle off the Enforced button.

Step 3: Apply the policy to a service

After creating and enforcing your Policy Set, it is automatically evaluated whenever a service event matches the configured trigger.

1. Go to Deployments → Services → New Service (or edit an existing service).

2. Configure the service and click Save.

3. Based on your selection in the Policy Evaluation criteria:

   • If the service meets the policy, it is saved successfully.

   • If the service violates the policy and the severity is Warn & continue, it is saved with a warning.

   • If the service violates the policy and the severity is Error and exit, the save is blocked and an error is displayed.

OnSave enforcement for Git-backed services

When a service is stored in Git, commits made directly to the Git repository bypass the Harness UI save flow. Harness now evaluates onSave policies when a Git-backed service changes via a webhook, and surfaces the result on the service detail page. A Service Validation Failed badge appears in the service header when the latest commit violates an onSave policy. If the invalid service is used in a pipeline execution, Harness fails the execution at the step where the service is referenced.

Go to Enforce onSave policies on Git entities to understand how this enforcement works across all Git-backed entity types.

See also

• Harness Governance Overview

• Policy Samples