Google Cloud Organization Policy vs Open Policy Agent Gatekeeper

Google Cloud Organization Policy lets administrators set constraints on Google Cloud resources across organizations, folders, and projects. Descendant resources inherit policies by default, so teams can establish restrictions across a resource hierarchy. Examples include limiting resource sharing by domain, restricting IAM service account use, and limiting where new resources may be created. Organizations can define custom constraints for resource creation and updates. Policies can be managed in the Google Cloud console, CLI, or REST API; the API exposes policy and constraint resources at organization, folder, and project levels. Dry-run policies record violations in audit logs without blocking the action, while Policy Intelligence tools can test proposed changes, identify non-compliant resources, monitor workflow impact, and show policy coverage. The service is free, with the Organization Policy Service API listed at free. Policies use YAML and JSON. Changes can take up to 15 minutes to take effect, and most enforcement is not retroactive. Basic Support is included for Google Cloud customers; paid technical support tiers are also available.

Open Policy Agent Gatekeeper is a free, open-source Kubernetes policy controller for Linux and self-hosted deployments. It runs as a validating and mutating webhook, enforcing CRD-based policies evaluated by Open Policy Agent. Validation constraints can deny requests, warn, run in dry-run mode or report violations without changing resources. Mutation policies can alter matching resources during admission before validation checks the final object. An audit function periodically evaluates existing cluster resources against constraints to identify pre-existing misconfigurations. The project includes an extensible policy library with parameterized examples, and provider connections to external data such as image registries and directory services. Named integrations or backed services include Azure Policy for Kubernetes, Google Kubernetes Engine Policy Controller, Rancher, AWS EKS Blueprints and Alibaba Cloud. Installation options include prebuilt, development or locally built images and Helm. Gatekeeper requires Kubernetes resources introduced in version 1.16 and cluster-admin permissions for installation. The gator CLI is documented as beta from version 3.11.