apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: redis
  labels:
    app: redis
    namespace: redis
spec:
  serviceName: redis
  replicas: 1
  selector:
    matchLabels:
      app: redis
  template:
    metadata:
      labels:
        app: redis
    spec:
      initContainers:
        - name: config
          image: redis:7.0.6
          command: [ "sh", "-c" ]
          args:
            - |
              cp /tmp/redis/redis.conf /etc/redis/redis.conf
              
              echo "finding master..."
              MASTER_FDQN=`hostname  -f | sed -e 's/redis-[0-9]\./redis-0./'`
              if [ "$(redis-cli -h sentinel -p 5000 ping)" != "PONG" ]; then
                echo "master not found, defaulting to redis-0"
                if [ "$(hostname)" = "redis-0" ]; then
                  echo "this is redis-0, not updating config..."
                else
                  echo "updating redis.conf..."
                  echo "\nslaveof $MASTER_FDQN 6379" >> /etc/redis/redis.conf
                fi
              else
                echo "sentinel found, finding master"
                MASTER="$(redis-cli -h sentinel -p 5000 sentinel get-master-addr-by-name mymaster | grep -E '(^redis-\d{1,})|([0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3})')"
                echo "master found : $MASTER, updating redis.conf"
                echo "slaveof $MASTER 6379" >> /etc/redis/redis.conf
              fi
          volumeMounts:
            - name: redis-config
              mountPath: /etc/redis/
            - name: config
              mountPath: /tmp/redis/
      containers:
        - name: redis
          image: redis:7.0.6
          command: [ "redis-server" ]
          args: [ "/etc/redis/redis.conf" ]
          ports:
            - containerPort: 6379
              name: redis
          volumeMounts:
            - name: data
              mountPath: /data
            - name: redis-config
              mountPath: /etc/redis/
          resources:
            limits:
              memory: 1100Mi
            requests:
              memory: 1100Mi
      volumes:
        - name: redis-config
          emptyDir: { }
        - name: config
          configMap:
            name: redis-config
  volumeClaimTemplates:
    - metadata:
        name: data
      spec:
        storageClassName: hostpath
        accessModes:
          - ReadWriteOnce
        resources:
          requests:
            storage: 500Mi

---
apiVersion: v1                # API version
kind: Service                 # Type of the kubernetes resource
metadata:
  name: redis                 # Name of the kubernetes resource
  labels: # Labels that will be applied to this resource
    app: redis
  namespace: redis
spec:
  selector:
    app: redis                 # The service exposes Pods with label `app=redis`
  ports:
    - name: redis-port
      port: 6379
      nodePort: 30079
  type: NodePort