helm: add network policy

Signed-off-by: Simon L. <szaimen@e.mail.de>

nextcloud-aio-helm-chart/templates/nextcloud-aio-networkpolicy.yaml

@@ -0,0 +1,14 @@
+{{- if eq .Values.NETWORK_POLICY_ENABLED "yes" }}
+# https://github.com/ahmetb/kubernetes-network-policy-recipes/blob/master/04-deny-traffic-from-other-namespaces.md
+kind: NetworkPolicy
+apiVersion: networking.k8s.io/v1
+metadata:
+  namespace: "{{ .Values.NAMESPACE }}"
+  name: nextcloud-aio-deny-from-other-namespaces
+spec:
+  podSelector:
+    matchLabels:
+  ingress:
+  - from:
+    - podSelector: {}
+{{- end }}