coredns-template.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: {{ .DeployName }}
  labels:
    k8s-app: {{ .DeployName }}
spec:
  replicas: 2
  strategy:
    type: RollingUpdate
    rollingUpdate:
      maxUnavailable: 1
  selector:
    matchLabels:
      k8s-app: {{ .DeployName }}
  template:
    metadata:
      labels:
        k8s-app: {{ .DeployName }}
    spec:
      priorityClassName: system-cluster-critical
      serviceAccountName: vpc-dns
      tolerations:
        - key: "CriticalAddonsOnly"
          operator: "Exists"
      nodeSelector:
        kubernetes.io/os: linux
      affinity:
         podAntiAffinity:
           preferredDuringSchedulingIgnoredDuringExecution:
             - weight: 100
               podAffinityTerm:
                 labelSelector:
                  matchExpressions:
                  - key: k8s-app
                    operator: In
                    values: ["{{ .DeployName }}"]
                 topologyKey: kubernetes.io/hostname
      containers:
      - name: coredns
        image: {{ .CorednsImage }}
        imagePullPolicy: IfNotPresent
        resources:
          limits:
            memory: 170Mi
          requests:
            cpu: 100m
            memory: 70Mi
        args: [ "-conf", "/etc/coredns/Corefile" ]
        volumeMounts:
        - name: config-volume
          mountPath: /etc/coredns
          readOnly: true
        ports:
        - containerPort: 53
          name: dns
          protocol: UDP
        - containerPort: 53
          name: dns-tcp
          protocol: TCP
        - containerPort: 9153
          name: metrics
          protocol: TCP
        securityContext:
          allowPrivilegeEscalation: false
          capabilities:
            add:
            - NET_BIND_SERVICE
            drop:
            - ALL
          readOnlyRootFilesystem: true
      dnsPolicy: Default
      volumes:
        - name: config-volume
          configMap:
            name: vpc-dns-corefile
            items:
            - key: Corefile
              path: Corefile