Kube-faq

# Minimal Redis from Operator

Very much new workload inside OPenShift / OKD or Kubernetes using Redis as distributed cache or session storage.

To address this there's an operator (https://ot-container-kit.github.io/redis-operator/)

It's best to use a reald redis cluster. CPU and Memory usage is typically low:

- Top of 0.6 CPU, 0.7 Gig memory and 6 pods 

- Average of 0.1 CPU and less than 0.1 Gig memory

All values for a 3 count stateful set.

If you're using 1 Gig storage PVC's you're ending with 6 Gig storage consumption ;-)

## Install

- Install the Redis operator like it's mentioned in https://ot-container-kit.github.io/redis-operator/guide/installation.html 

- or use the Operator Tab in OpenShift / OKD

- or apply this YAML in OpenShift / OKD:

     ```yaml

apiVersion: operators.coreos.com/v1alpha1

kind: Subscription

metadata:

  name: redis-operator

  namespace: openshift-operators 

spec:

  channel: stable

  installPlanApproval: Automatic

  name: redis-operator

  source: community-operators

  sourceNamespace: openshift-marketplace

     ```

## Usage

In your namespace use the following yaml to get a redundant redis cluster.

Pay special attentions to:

- storage size

- storage class (should be block storage for best performance)

```yaml

apiVersion: redis.redis.opstreelabs.in/v1beta1

kind: RedisCluster

metadata:

  name: redis-cluster

spec:

  clusterSize: 3

  kubernetesConfig:

    image: 'quay.io/opstree/redis:v6.2.5'

    imagePullPolicy: IfNotPresent

    resources:

      limits:

        cpu: 101m

        memory: 128Mi

      requests:

        cpu: 101m

        memory: 128Mi

    serviceType: ClusterIP

  redisExporter:

    enabled: false

    image: 'quay.io/opstree/redis-exporter:1.0'

  redisFollower:

    serviceType: ClusterIP

  redisLeader:

    serviceType: ClusterIP

  storage:

    volumeClaimTemplate:

      spec:

        accessModes:

          - ReadWriteOnce

        resources:

          requests:

            storage: 1Gi

        storageClassName: rook-ceph-block

```