add namespace-protection

other/namespace-protection/namespace-protection.yaml

@@ -0,0 +1,39 @@
+apiVersion: kyverno.io/v2beta1
+kind: ClusterPolicy
+metadata:
+  name: namespace-protection
+  annotations:
+    policies.kyverno.io/title: Namespace Protection
+    policies.kyverno.io/category: Other
+    policies.kyverno.io/severity: medium
+    policies.kyverno.io/subject: Namespace
+    kyverno.io/kyverno-version: 1.9.0
+    policies.kyverno.io/minversion: 1.9.0
+    kyverno.io/kubernetes-version: "1.24"
+    policies.kyverno.io/description: >-
+      Cases where RBAC may be applied at a higher level and where Namespace-level
+      protections may be necessary can be accomplished with a separate policy. For example,
+      one may want to protect creates, updates, and deletes on only a single Namespace. This
+      policy will block creates, updates, and deletes to any Namespace labeled with `freeze=true`.
+      Caution should be exercised when using rules which match on all kinds (`"*"`) as this will
+      involve, for larger clusters, a substantial amount of processing on Kyverno's part. Additional
+      resource requests and/or limits may be required.
+spec:
+  validationFailureAction: Enforce
+  background: false
+  rules:
+    - name: check-freeze
+      match:
+        any:
+        - resources:
+            kinds:
+            - "*"
+            namespaceSelector:
+              matchExpressions:
+                - key: freeze
+                  operator: In
+                  values:
+                  - "true"
+      validate:
+        message: "This Namespace is frozen and no modifications may be performed."
+        deny: {}