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Open Policy Agent Gatekeeper📜

The Open Policy Agent (OPA) Gatekeeper assists in enforcing, monitoring, and remediating policies while strengthening governance of an environment. It provides integration between OPA and Kubernetes.

OPA Gatekeeper controls the policies for Kubernetes and acts as a customizable Kubernetes Admission Webhook. Its audit functionality offers constant monitoring of existing clusters to detect policy violations.

OPA Gatekeeper functionality includes:


To install and test the Gatekeeper application, follow these steps


  • A kubernetes cluster with cluster-admin access
  • Helm


  • Clone the application repository git clone
  • Change into the policy directory and lint the chart - make sure there are no errors. cd policy && helm lint chart
  • Install the chart helm upgrade -i -n gatekeeper-system --create-namespace --wait opa-gatekeeper chart --debug
  • Confirm the application installed with no issues.

    kubectl get po -n gatekeeper-system
    NAME                                            READY   STATUS    RESTARTS   AGE
    gatekeeper-audit-7997ddc847-8pt5h               1/1     Running   0          28s
    gatekeeper-controller-manager-7fdfd7bfd-8g5sm   1/1     Running   0          28s
    gatekeeper-controller-manager-7fdfd7bfd-khc7j   1/1     Running   0          28s
    gatekeeper-controller-manager-7fdfd7bfd-nzzd8   1/1     Running   0          28s

ConstraintTemplates and Constraints📜

The repo contains ConstraintTemplate and Constraints.

  • ConstraintTemplates describe both the Rego that enforces the constraint and the schema of the constraint. It is the same context as the ConstraintTemplate being a CRD with the schema definition and the Constraints being the CRs passing parameters.

You can find ConstraintTemplates in /chart/templates/constraint-templates.

  • Constraints represent the instantiation of the ConstraintTemplates. They inform Gatekeeper that the admin wants a ConstraintTemplate to be enforced, and how.

You can find Constraint in /chart/templates/constraints.

Further information on Constraints and ConstraintTemplates:

For additional info on the architecture and how OPA fits into Big Bang see the Architecture Doc.

Last update: 2022-01-04 by Micah Nagel