Mount bind cache as empty dir

deployments/dns/bind.yaml

@@ -97,6 +97,8 @@ spec:
       labels:
         app: bind-master
     spec:
+      securityContext:
+        fsGroup: 999
       containers:
       - name: bind-master
         image: internetsystemsconsortium/bind9:9.18
@@ -116,6 +118,8 @@ spec:
         - name: dns-secrets
           mountPath: /etc/bind/externaldns-key.conf
           subPath: externaldns-key.conf
+        - name: bind-cache
+          mountPath: /var/cache/bind
       volumes:
       - name: dns-secrets
         secret:
@@ -123,6 +127,8 @@ spec:
       - name: config
         configMap:
           name: bind-master-config
+      - name: bind-cache
+        emptyDir: {}
 ---
 apiVersion: apps/v1
 kind: DaemonSet
@@ -140,6 +146,8 @@ spec:
     spec:
       hostNetwork: true
       dnsPolicy: ClusterFirstWithHostNet
+      securityContext:
+        fsGroup: 999
       containers:
       - name: bind9
         image: internetsystemsconsortium/bind9:9.18