00-Redis Cluster in OpenShift.md

• Installing the Redis Operator

# create namespace for operator
oc create ns redis-operator

# register Helm repo
helm repo add ot-helm https://ot-container-kit.github.io/helm-charts/

# install redis-operator using helm
helm upgrade redis-operator ot-helm/redis-operator \
--install --namespace redis-operator

# validate operator is running
oc get pods -n redis-operator
NAME                              READY   STATUS    RESTARTS   AGE
redis-operator-78c6c95b78-4w5qp   1/1     Running   0          86m

• The redis cluster has as pre-requisite for the cluster to have persistent storage. For lab setup with external NFS server.

# create PVs
oc create -f 02-redis-pvs.yaml

# example verificaton
oc get pv
NAME   CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS      CLAIM                    STORAGECLASS   REASON   AGE
pv1    5Gi        RWO            Retain           Available                            slow                    10m
pv2    5Gi        RWO            Retain           Available                            slow                    10m
pv3    5Gi        RWO            Retain           Available                            slow                    10m
pv4    5Gi        RWO            Retain           Available                            slow                    10m
pv5    5Gi        RWO            Retain           Available                            slow                    10m
pv6    5Gi        RWO            Retain           Available                            slow                    10m

• Deploy redis cluster in redis-cluster namespace

# create CR definition
oc create -f 03-redis-cluster.yaml

# NOTE: it will bring one leader and follower at a time and
# only when those are sync, it will proceed with the next one.
# It may take several minutes for all the pods to become available.

# Sample validation
oc get pvc
NAME                                              STATUS   VOLUME   CAPACITY   ACCESS MODES   STORAGECLASS   AGE
redis-cluster-follower-redis-cluster-follower-0   Bound    pv2      5Gi        RWO            slow           22m
redis-cluster-follower-redis-cluster-follower-1   Bound    pv1      5Gi        RWO            slow           22m
redis-cluster-follower-redis-cluster-follower-2   Bound    pv4      5Gi        RWO            slow           21m
redis-cluster-leader-redis-cluster-leader-0       Bound    pv5      5Gi        RWO            slow           22m
redis-cluster-leader-redis-cluster-leader-1       Bound    pv6      5Gi        RWO            slow           22m
redis-cluster-leader-redis-cluster-leader-2       Bound    pv3      5Gi        RWO            slow           21m
oc get pods
NAME                       READY   STATUS    RESTARTS   AGE
redis-cluster-follower-0   2/2     Running   0          23m
redis-cluster-follower-1   2/2     Running   0          22m
redis-cluster-follower-2   2/2     Running   0          22m
redis-cluster-leader-0     2/2     Running   0          23m
redis-cluster-leader-1     2/2     Running   0          22m
redis-cluster-leader-2     2/2     Running   0          22m

02-redis-pvs.yaml

---
apiVersion: v1
kind: PersistentVolume
metadata:
  name: pv1
spec:
  capacity:
    storage: 5Gi
  accessModes:
    - ReadWriteOnce
  persistentVolumeReclaimPolicy: Retain
  storageClassName: slow
  nfs:
    path: /kvm-nfs/pv1
    server: 192.168.1.15
---
apiVersion: v1
kind: PersistentVolume
metadata:
  name: pv2
spec:
  capacity:
    storage: 5Gi
  accessModes:
    - ReadWriteOnce
  persistentVolumeReclaimPolicy: Retain
  storageClassName: slow
  nfs:
    path: /kvm-nfs/pv2
    server: 192.168.1.15
---
apiVersion: v1
kind: PersistentVolume
metadata:
  name: pv3
spec:
  capacity:
    storage: 5Gi
  accessModes:
    - ReadWriteOnce
  persistentVolumeReclaimPolicy: Retain
  storageClassName: slow
  nfs:
    path: /kvm-nfs/pv3
    server: 192.168.1.15
---
apiVersion: v1
kind: PersistentVolume
metadata:
  name: pv4
spec:
  capacity:
    storage: 5Gi
  accessModes:
    - ReadWriteOnce
  persistentVolumeReclaimPolicy: Retain
  storageClassName: slow
  nfs:
    path: /kvm-nfs/pv4
    server: 192.168.1.15
---
apiVersion: v1
kind: PersistentVolume
metadata:
  name: pv5
spec:
  capacity:
    storage: 5Gi
  accessModes:
    - ReadWriteOnce
  persistentVolumeReclaimPolicy: Retain
  storageClassName: slow
  nfs:
    path: /kvm-nfs/pv5
    server: 192.168.1.15
---
apiVersion: v1
kind: PersistentVolume
metadata:
  name: pv6
spec:
  capacity:
    storage: 5Gi
  accessModes:
    - ReadWriteOnce
  persistentVolumeReclaimPolicy: Retain
  storageClassName: slow
  nfs:
    path: /kvm-nfs/pv6
    server: 192.168.1.15

03-redis-cluster.yaml

# Redis Cluster
--- 
apiVersion: v1
kind: Namespace
metadata:
  name: redis-cluster
spec: {}
---
apiVersion: redis.redis.opstreelabs.in/v1beta1
kind: RedisCluster
metadata:
  name: redis-cluster
  namespace: redis-cluster
spec:
  redisLeader:
    serviceType: ClusterIP
    replicas: 3
  kubernetesConfig:
    resources:
      limits:
        cpu: 150m
        memory: 128Mi
      requests:
        cpu: 150m
        memory: 128Mi
    image: 'quay.io/opstree/redis:v6.2.5'
    imagePullPolicy: IfNotPresent
    serviceType: ClusterIP
  redisFollower:
    serviceType: ClusterIP
    replicas: 3
  storage:
    volumeClaimTemplate:
      spec:
        storageClassName: slow
        accessModes:
          - ReadWriteOnce
        resources:
          requests:
            storage: 1Gi
  redisExporter:
    enabled: true
    image: 'quay.io/opstree/redis-exporter:1.0'
  clusterSize: 3