When working with Open Policy Agent (OPA), you might find that policies created via the REST API endpoint /v1/policies/{id} are stored in memory. This means that if the OPA server is restarted, all policies will be lost. To avoid this issue and ensure your policies are persistent, you need to configure OPA to use a storage backend.

Steps to Persist Policies

  1. Choose a Storage Backend: OPA supports various storage backends, including file-based storage and databases. For simplicity, we will focus on file storage in this example.

  2. Configure OPA: You need to modify the OPA configuration file to specify the storage backend. Here’s an example configuration that uses file storage:

services:
  - name: example
    url: http://localhost:8181

bundles:
  example:
    service: example
    resource: example/bundle.tar.gz

storage:
  type: file
  path: /path/to/policies

In this configuration:

  • The storage section specifies that the type is file and provides a path where the policies will be saved.

  1. Deploy OPA: After updating the configuration, restart the OPA server. It will now save any policies you create to the specified file path.

  2. Verify Persistence: To ensure that your policies are indeed persistent, create a policy using the REST API, then restart the OPA server. After the restart, check the specified file path to confirm that your policies are still available.

Conclusion

By configuring OPA to use a file-based storage backend, you can ensure that your policies are retained even after server reboots. This setup is crucial for maintaining compliance and security in your applications.