kyverno/charts/kyverno-policies/templates/restricted/disallow-capabilities-strict.yaml

{{- $name := "disallow-capabilities-strict" }}
{{- if eq (include "kyverno-policies.podSecurityRestricted" (merge (dict "name" $name) .)) "true" }}
{{- include "kyverno-policies.supportedKyvernoCheck" (dict "top" . "ver" ">= 1.6.0-0") }}
apiVersion: kyverno.io/v1
kind: ClusterPolicy
metadata:
  name: {{ $name }}
  annotations:
    policies.kyverno.io/title: Disallow Capabilities (Strict)
    policies.kyverno.io/category: Pod Security Standards (Restricted)
    {{- if .Values.podSecuritySeverity }}
    policies.kyverno.io/severity: {{ .Values.podSecuritySeverity | quote }}
    {{- end }}
    policies.kyverno.io/minversion: 1.6.0
    kyverno.io/kyverno-version: 1.6.0
    kyverno.io/kubernetes-version: "1.22-1.23"
    policies.kyverno.io/subject: Pod
    policies.kyverno.io/description: >-
      Adding capabilities other than `NET_BIND_SERVICE` is disallowed. In addition,
      all containers must explicitly drop `ALL` capabilities.
spec:
  validationFailureAction: {{ .Values.validationFailureAction }}
  {{- with concat (index .Values "validationFailureActionOverrides" "all") (default list (index .Values "validationFailureActionOverrides" $name)) }}
  validationFailureActionOverrides: {{ toYaml . | nindent 4 }}
  {{- end }}
  background: {{ .Values.background }}
  failurePolicy: {{ .Values.failurePolicy }}
  rules:
    - name: require-drop-all
      match:
        any:
        - resources:
            kinds:
              - Pod
      {{- with merge (index .Values "policyExclude" "require-drop-all") (index .Values "policyExclude" $name) }}
      exclude:
        {{- toYaml . | nindent 8 }}
      {{- end }}
      {{- $preconditions1 :=  merge (index .Values "policyPreconditions" "require-drop-all") (index .Values "policyPreconditions" $name) }}
      {{- if $preconditions1 }}
      {{- with $preconditions1 }}
      preconditions:
        {{- if .all }}
        all:
        - key: "{{`{{ request.operation }}`}}"
          operator: NotEquals
          value: DELETE
        {{- toYaml .all | nindent 8 }}
        {{- else }}
          {{- toYaml . | nindent 8 }}
        {{- end }}
      {{- end }}
      {{- else }}
      preconditions:
        all:
        - key: "{{`{{ request.operation }}`}}"
          operator: NotEquals
          value: DELETE
      {{- end }}
      validate:
        message: >-
          Containers must drop `ALL` capabilities.
        foreach:
          - list: request.object.spec.[ephemeralContainers, initContainers, containers][]
            deny:
              conditions:
                all:
                - key: ALL
                  operator: AnyNotIn
                  value: "{{`{{ element.securityContext.capabilities.drop || '' }}`}}"
    - name: adding-capabilities-strict
      match:
        any:
        - resources:
            kinds:
              - Pod
      {{- with merge (index .Values "policyExclude" "adding-capabilities-strict") (index .Values "policyExclude" $name) }}
      exclude:
        {{- toYaml . | nindent 8 }}
      {{- end }}
      {{- $preconditions2 := merge (index .Values "policyPreconditions" "adding-capabilities-strict") (index .Values "policyPreconditions" $name) }}
      {{- if $preconditions2 }}
      {{- with $preconditions2 }}
      preconditions:
        {{- if .all }}
        all:
        - key: "{{`{{ request.operation }}`}}"
          operator: NotEquals
          value: DELETE
        {{- toYaml .all | nindent 8 }}
        {{- else }}
          {{- toYaml . | nindent 8 }}
        {{- end }}
      {{- end }}
      {{- else }}
      preconditions:
        all:
        - key: "{{`{{ request.operation }}`}}"
          operator: NotEquals
          value: DELETE
      {{- end }}
      validate:
        message: >-
          Any capabilities added other than NET_BIND_SERVICE are disallowed.
        foreach:
          - list: request.object.spec.[ephemeralContainers, initContainers, containers][]
            deny:
              conditions:
                all:
                - key: "{{`{{ element.securityContext.capabilities.add[] || '' }}`}}"
                  operator: AnyNotIn
                  value:
                  - NET_BIND_SERVICE
                  - ''
{{- end }}