kyverno/charts/kyverno-policies/templates/default/disallow-adding-capabilities.yaml

{{- $name := "disallow-add-capabilities" }}
{{- if eq (include "kyverno-policies.podSecurityBaseline" (merge (dict "name" $name) .)) "true" }}
apiVersion: kyverno.io/v1
kind: ClusterPolicy
metadata:
  name: {{ $name }}
  annotations:
    policies.kyverno.io/category: Pod Security Standards (Default)
    {{- if .Values.podSecuritySeverity }}
    policies.kyverno.io/severity: {{ .Values.podSecuritySeverity | quote }}
    {{- end }}
    policies.kyverno.io/description: >-
      Capabilities permit privileged actions without giving full root access.
      Adding capabilities beyond the default set must not be allowed.
  labels: {{ include "kyverno-policies.labels" . | nindent 4 }}
    app: kyverno
spec:
  validationFailureAction: {{ .Values.validationFailureAction }}
  background: true
  rules:
  - name: capabilities
    match:
      resources:
        kinds:
        - Pod
    validate:
      message: >-
        Adding of additional capabilities beyond the default set is not allowed.
        The fields spec.containers[*].securityContext.capabilities.add and
        spec.initContainers[*].securityContext.capabilities.add must be empty.
      pattern:
        spec:
          containers:
          - =(securityContext):
              =(capabilities):
                X(add): null
          =(initContainers):
          - =(securityContext):
              =(capabilities):
                X(add): null
{{- end -}}