2.5.10. gatekeeper 制約および制約テンプレートの統合

ConstraintTemplates と制約: policy-gatekeeper-k8srequiredlabels を使用して、マネージドクラスターで gatekeeper 制約テンプレートを作成します。

apiVersion: policy.open-cluster-management.io/v1
kind: ConfigurationPolicy
metadata:
  name: policy-gatekeeper-k8srequiredlabels
spec:
  remediationAction: enforce # will be overridden by remediationAction in parent policy
  severity: low
  object-templates:
    - complianceType: musthave
      objectDefinition:
        apiVersion: templates.gatekeeper.sh/v1beta1
        kind: ConstraintTemplate
        metadata:
          name: k8srequiredlabels
        spec:
          crd:
            spec:
              names:
                kind: K8sRequiredLabels
              validation:
                # Schema for the `parameters` field
                openAPIV3Schema:
                  properties:
                    labels:
                      type: array
                      items: string
          targets:
            - target: admission.k8s.gatekeeper.sh
              rego: |
                package k8srequiredlabels
                violation[{"msg": msg, "details": {"missing_labels": missing}}] {
                  provided := {label | input.review.object.metadata.labels[label]}
                  required := {label | label := input.parameters.labels[_]}
                  missing := required - provided
                  count(missing) > 0
                  msg := sprintf("you must provide labels: %v", [missing])
                }
    - complianceType: musthave
      objectDefinition:
        apiVersion: constraints.gatekeeper.sh/v1beta1
        kind: K8sRequiredLabels
        metadata:
          name: ns-must-have-gk
        spec:
          match:
            kinds:
              - apiGroups: [""]
                kinds: ["Namespace"]
            namespaces:
              - e2etestsuccess
              - e2etestfail
          parameters:
            labels: ["gatekeeper"]

監査テンプレート: policy-gatekeeper-audit を使用して、既存の設定ミスを検出するために適用された gatekeeper ポリシーに対して、既存のリソースを定期的に確認して評価します。

apiVersion: policy.open-cluster-management.io/v1
kind: ConfigurationPolicy
metadata:
  name: policy-gatekeeper-audit
spec:
  remediationAction: inform # will be overridden by remediationAction in parent policy
  severity: low
  object-templates:
    - complianceType: musthave
      objectDefinition:
        apiVersion: constraints.gatekeeper.sh/v1beta1
        kind: K8sRequiredLabels
        metadata:
          name: ns-must-have-gk
        status:
          totalViolations: 0

受付テンプレート: policy-gatekeeper-admission を使用して、gatekeeper 受付 Webhook によって作成される設定ミスを確認します。

apiVersion: policy.open-cluster-management.io/v1
kind: ConfigurationPolicy
metadata:
  name: policy-gatekeeper-admission
spec:
  remediationAction: inform # will be overridden by remediationAction in parent policy
  severity: low
  object-templates:
    - complianceType: mustnothave
      objectDefinition:
        apiVersion: v1
        kind: Event
        metadata:
          namespace: openshift-gatekeeper-system # set it to the actual namespace where gatekeeper is running if different
          annotations:
            constraint_action: deny
            constraint_kind: K8sRequiredLabels
            constraint_name: ns-must-have-gk
            event_type: violation