apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: redis
spec:
  selector:
    matchLabels:
      app: redis-sts
  serviceName: redis-service
  replicas: 3
  template:
    metadata:
      labels:
        app: redis-sts
    spec:
      terminationGracePeriodSeconds: 10
      initContainers:
      - name: init-redis
        image: redis:latest
        command:
        - bash
        - "-c"
        - |
          set -ex
          # Generate server-id from Pod ordinal index.
          [[ `hostname` =~ -([0-9]+)$ ]] || exit 1
          ordinal=${BASH_REMATCH[1]}
          echo "ordinal ${ordinal}"
          # Copy appropriate config files from config-map to emptyDir.
          mkdir -p /redis/conf/
          if [[ $ordinal -eq 0 ]]; then
            cp /mnt/redis-configmap/primary.conf /redis/conf/redis.conf
          else
            cp /mnt/redis-configmap/replica.conf /redis/conf/redis.conf
          fi
          cat /redis/conf/redis.conf
        volumeMounts:
        - name: redis-config-volume
          mountPath: /redis/conf/
        - name: redis-configmap-volume
          mountPath: /mnt/redis-configmap
      containers:
      - name: redis-container
        image: redis:latest
        command: ["redis-server"]
        args: ["/redis/conf/redis.conf"]
        volumeMounts:
        - name: redis-config-volume
          mountPath: /redis/conf/
        - name: redis-pvc
          mountPath: /redis/data
        resources:
          requests:
            cpu: 1
            memory: 4Gi
      volumes:
      - name: redis-configmap-volume
        configMap:
          name: redis-role-config
      - name: redis-config-volume
        emptyDir: {}
  volumeClaimTemplates:
  - metadata:
      name: redis-pvc
    spec:
      accessModes: [ "ReadWriteOnce" ]
      resources:
        requests:
          storage: 1Gi
---
apiVersion: v1
kind: Service
metadata:
  name: redis-service
spec:
  ports:
  - port: 6379
  clusterIP: None
  selector:
    app: redis-sts