feat/nginz: add zone-based topology constraint

changelog.d/5-internal/nginz-zone-topology

@@ -0,0 +1,2 @@
+Add zone-level topologySpreadConstraints to nginz deployment so pods are spread evenly across availability zones, ensuring traffic reaches all AZs when zone-aware routing is in use.
+topologySpreadConstraints are now configurable via values.yaml (defaulting to zone + hostname spreading), allowing chart users to customise pod scheduling without patching the chart.

charts/nginz/templates/deployment.yaml

@@ -29,13 +29,10 @@ spec:
         fluentbit.io/parser-nginz: nginz
     spec:
       terminationGracePeriodSeconds: {{ .Values.terminationGracePeriodSeconds }}
+      {{- with .Values.topologySpreadConstraints }}
       topologySpreadConstraints:
-        - maxSkew: 1
-          topologyKey: "kubernetes.io/hostname"
-          whenUnsatisfiable: ScheduleAnyway
-          labelSelector:
-            matchLabels:
-              app: nginz
+        {{- toYaml . | nindent 8 }}
+      {{- end }}
       containers:
       - name: nginz
         image: "{{ .Values.images.nginz.repository }}:{{ .Values.images.nginz.tag }}"

charts/nginz/values.yaml

@@ -20,6 +20,19 @@ config:
     wsPort: 8081
     useProxyProtocol: true
 terminationGracePeriodSeconds: 90
+topologySpreadConstraints:
+  - maxSkew: 1
+    topologyKey: "topology.kubernetes.io/zone"
+    whenUnsatisfiable: ScheduleAnyway
+    labelSelector:
+      matchLabels:
+        app: nginz
+  - maxSkew: 1
+    topologyKey: "kubernetes.io/hostname"
+    whenUnsatisfiable: ScheduleAnyway
+    labelSelector:
+      matchLabels:
+        app: nginz
 nginx_conf:
   dns_resolver: kube-dns
   cluster_domain: cluster.local