Add validating admission policy to restrict upstream driver access (#482)

* Add validating admission policy to restrict upstream driver access Signed-off-by: Kevin Fox <[email protected]> * Update charts/spire/charts/spiffe-csi-driver/templates/policy.yaml Signed-off-by: kfox1111 <[email protected]> * Fix logic Signed-off-by: Kevin Fox <[email protected]> * Upgrade helm Signed-off-by: Kevin Fox <[email protected]> * Upgrade kind and fix node version Signed-off-by: Kevin Fox <[email protected]> * Upgrade kind and fix node version Signed-off-by: Kevin Fox <[email protected]> * Upgrade kind and fix node version Signed-off-by: Kevin Fox <[email protected]> * Upgrade kind and fix node version Signed-off-by: Kevin Fox <[email protected]> * Add version info Signed-off-by: Kevin Fox <[email protected]> * Add version info Signed-off-by: Kevin Fox <[email protected]> * Fix kind version Signed-off-by: Kevin Fox <[email protected]> * Fix kind version Signed-off-by: Kevin Fox <[email protected]> * Fix kind version Signed-off-by: Kevin Fox <[email protected]> * Fix detection Signed-off-by: Kevin Fox <[email protected]> * Just for testing... Signed-off-by: Kevin Fox <[email protected]> * Just for testing... Signed-off-by: Kevin Fox <[email protected]> * Just for testing Signed-off-by: Kevin Fox <[email protected]> * Fix policy Signed-off-by: Kevin Fox <[email protected]> * Fix policy Signed-off-by: Kevin Fox <[email protected]> * Fix policy Signed-off-by: Kevin Fox <[email protected]> * Incorperate feedback Signed-off-by: Kevin Fox <[email protected]> * Update charts/spire/charts/spiffe-csi-driver/values.yaml Co-authored-by: Faisal Memon <[email protected]> Signed-off-by: kfox1111 <[email protected]> * Update docs Signed-off-by: Kevin Fox <[email protected]> --------- Signed-off-by: Kevin Fox <[email protected]> Signed-off-by: kfox1111 <[email protected]> Co-authored-by: Faisal Memon <[email protected]>
2024-10-26 07:40:29 -07:00
parent a7368eee1f
commit a360646842
9 changed files with 144 additions and 78 deletions
@@ -40,6 +40,23 @@ Allow the release namespace to be overridden for multi-namespace deployments in
  {{- end -}}
 {{- end -}}

+{{/*
+Allow the release namespace to be overridden for multi-namespace deployments in combined charts
+*/}}
+{{- define "spiffe-csi-driver.server-namespace" -}}
+  {{- if .Values.serverNamespaceOverride -}}
+    {{- .Values.serverNamespaceOverride -}}
+  {{- else if and (dig "spire" "recommendations" "enabled" false .Values.global) (dig "spire" "recommendations" "namespaceLayout" true .Values.global) }}
+    {{- if ne (len (dig "spire" "namespaces" "server" "name" "" .Values.global)) 0 }}
+      {{- .Values.global.spire.namespaces.server.name }}
+    {{- else }}
+      {{- printf "spire-server" }}
+    {{- end }}
+  {{- else -}}
+    {{- .Release.Namespace -}}
+  {{- end -}}
+{{- end -}}
+
 {{/*
 Create chart name and version as used by the chart label.
 */}}
@@ -0,0 +1,37 @@
+{{- $upstream := eq .Values.pluginName "upstream.csi.spiffe.io" }}
+{{- $detectedValidation := semverCompare ">=1.30-0" .Capabilities.KubeVersion.GitVersion -}}
+{{- $policyEnabled := .Values.validatingAdmissionPolicy.enabled | toString }}
+{{- $auto := eq $policyEnabled "auto" }}
+{{- if or (eq $policyEnabled "true") (and $auto $upstream $detectedValidation) }}
+apiVersion: admissionregistration.k8s.io/v1
+kind: ValidatingAdmissionPolicy
+metadata:
+  name: {{ .Values.pluginName | quote }}
+spec:
+  failurePolicy: Fail
+  matchConstraints:
+    resourceRules:
+    - apiGroups:   [""]
+      apiVersions: ["v1"]
+      operations:  ["CREATE", "UPDATE"]
+      resources:   ["pods"]
+  validations:
+  - expression: |
+      !object.spec.volumes.exists(c, has(c.csi) && has(c.csi.driver) && c.csi.driver == {{ .Values.pluginName | quote }})
+    message: 'you may not use the upstream.csi.spiffe.io csi driver'
+---
+apiVersion: admissionregistration.k8s.io/v1
+kind: ValidatingAdmissionPolicyBinding
+metadata:
+  name: {{ .Values.pluginName | quote }}
+spec:
+  policyName: {{ .Values.pluginName | quote }}
+  validationActions: ["Deny"]
+  matchResources:
+    namespaceSelector:
+      matchExpressions:
+      - key: "kubernetes.io/metadata.name"
+        operator: NotIn
+        values:
+        - {{ include "spiffe-csi-driver.server-namespace" . | quote }}
+{{- end }}