fix(monitoring): Add basic network policy

infrastructure/monitoring/kustomization.yaml

@@ -5,3 +5,4 @@ resources:
   - namespace.yaml
   - repository.yaml
   - release.yaml
+  - ../../shared/networkpolicies/allow-from-same-namespace.yaml

shared/networkpolicies/allow-from-same-namespace.yaml

+---
+apiVersion: networking.k8s.io/v1
+kind: NetworkPolicy
+name: allow-from-same-namespace
+data:
+  spec:
+    podSelector: {}
+    ingress:
+    - from:
+      - podSelector: {}