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Redis cluster on minikube stays in "pending" state

Time:01-31

I have installed minikube on local windows machine. Trying to install redis cluster. I ran all cluster using kubectl create -f <resource> -n <namespace>. Following are the files that were used to create clusters.

  1. Storage class
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: local-storage
provisioner: kubernetes.io/no-provisioner
volumeBindingMode: WaitForFirstConsumer
allowVolumeExpansion: true
reclaimPolicy: Delete
  1. Persistent volumes.
kind: PersistentVolume
metadata:
  name: local-pv1
spec:
  storageClassName: local-storage
  capacity:
    storage: 1Gi
  accessModes:
    - ReadWriteOnce
  hostPath:
    path: "/storage/data1"

---

apiVersion: v1
kind: PersistentVolume
metadata:
  name: local-pv2
spec:
  storageClassName: local-storage
  capacity:
    storage: 1Gi
  accessModes:
    - ReadWriteOnce
  hostPath:
    path: "/storage/data2"

---

apiVersion: v1
kind: PersistentVolume
metadata:
  name: local-pv3
spec:
  storageClassName: local-storage
  capacity:
    storage: 2Gi
  accessModes:
    - ReadWriteOnce
  hostPath:
    path: "/storage/data3"
  1. Redis config map
apiVersion: v1
kind: ConfigMap
metadata:
  name: redis-cluster
  labels:
    app: redis-cluster
data:
  fix-ip.sh: |
    #!/bin/sh
    CLUSTER_CONFIG="/data/nodes.conf"
    echo "creating nodes"
    if [ -f ${CLUSTER_CONFIG} ]; then
      echo "[ INFO ]File:${CLUSTER_CONFIG} is Found"
    else
      touch $CLUSTER_CONFIG
    fi
    if [ -z "${POD_IP}" ]; then
      echo "Unable to determine Pod IP address!"
      exit 1
    fi
    echo "Updating my IP to ${POD_IP} in ${CLUSTER_CONFIG}"
    sed -i.bak -e "/myself/ s/[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}/${POD_IP}/" ${CLUSTER_CONFIG}
    echo "done"
    exec "$@"
  redis.conf: | 
    cluster-enabled yes
    cluster-require-full-coverage no
    cluster-node-timeout 15000
    cluster-config-file /data/nodes.conf
    cluster-migration-barrier 1
    appendonly yes
    protected-mode no
  1. Statefulset redis cluster
apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: redis
spec:
  serviceName: redis
  replicas: 3
  selector:
    matchLabels:
      app: redis
  template:
    metadata:
      labels:
        app: redis
    spec:
      initContainers:
      - name: config
        image: redis:6.2.3-alpine
        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 "slaveof $MASTER_FDQN 6379" >> /etc/redis/redis.conf
              fi
            else
              echo "sentinel found, finding master"
              MASTER="$(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:6.2.3-alpine
        command: ["redis-server"]
        args: ["/etc/redis/redis.conf"]
        ports:
        - containerPort: 6379
          name: redis
        volumeMounts:
        - name: data
          mountPath: /data
        - name: redis-config
          mountPath: /etc/redis/
      volumes:
      - name: redis-config
        emptyDir: {}
      - name: config
        configMap:
          name: redis-config
  volumeClaimTemplates:
  - metadata:
      name: data
    spec:
      accessModes: [ "ReadWriteOnce" ]
      storageClassName: "local-storage"
      resources:
        requests:
          storage: 500Mi
  1. Head less redis service
apiVersion: v1
kind: Service
metadata:
  name: redis-cluster
  namespace: redis
spec:
  type: ClusterIP
  ports:
  - port: 6379
    targetPort: 6379
    name: client
  - port: 16379
    targetPort: 16379
    name: gossip
  selector:
    app: redis-cluster

This is what comes on getting pods

redis-cluster-0   0/1     Pending   0          2d 

On describing the pods this is the message shown. Not sure if this is an issue

Warning  FailedScheduling  6m24s (x110 over 46h)  default-scheduler  0/1 nodes are available: 1 pod has unbound immediate PersistentVolumeClaims. preemption: 0/1 nodes are available: 1 Preemption is not helpful for scheduling.

CodePudding user response:

It's likely that your cluster has no storageClassName: local-storage. Check your storage classes using kubectl get sc. To fix this, you need to do any of the following:

  1. Create a storage class called local-storage
  2. Modify your manifest file's storage-class field to any pre-existing SC.
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